Description
Title of Invention: BATTERY AND ASSEMBLED BATTERY
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Japanese Priority Patent Application JP
2013-258706 filed December 13, 2013, the entire contents of which are incorporated
herein by reference.
Technical Field
[0002] The present technology relates to a battery and an assembled battery. In detail, the
present technology relates to a battery equipped with a winding electrode and a sheath
material and an assembled battery equipped with the same.
Background Art
[0003] In recent years, miniaturization and weight reduction of portable devices such as a
mobile phone, a portable audio player, and a PDA (Personal Digital Assistant) have
been remarkably improved. The miniaturization of the battery to be mounted has
played a part of the technology improvement.
[0004] As a small battery, a battery in which a flat winding-type electrode body is housed a
film-like sheath material with high flexibility in molding has been proposed (for
example, see PTL 1). By using such a film-like sheath material, cell design appropriate
for portable electronic devices to be diversified is possible. In recent years, minia
turization of batteries using such a sheath material is desired.
Citation List
Patent Literature
[0005] PTL 1: Japanese Unexamined Patent Application Publication No. 2000-133215
Summary
Technical Problem
[0006] Therefore, it is desirable to provide a small battery equipped with a winding
electrode, a sheath material, and an assembled battery equipped with the same.
Solution to Problem
[0007] According to a first embodiment of the present technology, there is provided a
battery including a substantially cylindrically shaped winding electrode having a
hollow portion in the center, and a sheath material having flexibility which sheathes
the winding electrode, wherein a width of the hollow portion is 2.5 mm or less.
[0008] According to a second embodiment of the present technology, there is provided an
assembled battery including a plurality of batteries electrically connected in at least
one of parallel and series, wherein the batteries are equipped with a substantially cylin
drically shaped winding electrode having a hollow portion in the center and a sheath
material having flexibility which sheathes the winding electrode, and a width of the
hollow portion is 2.5 mm or less.
[0009] According to a third embodiment of the present technology, there is provided a
method of manufacturing a winding electrode for a battery, the method including
inserting a separator into a gap of a winding core, winding the winding core to wind
two portions of the separator around an outer peripheral surface of the winding core,
wherein at least one electrode is stacked on the separator, and removing the winding
core to leave a hollow portion in a central portion of the winding electrode. The
winding electrode is substantially cylindrically shaped. The hollow portion is sub
stantially cylindrically shaped with a diameter of 2.5 mm or less that extends along a
central axis of the winding electrode.
Advantageous Effects of Invention
[0010] As described above, according to the embodiments of the present technology, it is
possible to miniaturize the battery equipped with the winding electrode and the sheath
material.
Brief Description of Drawings
[001 1] [fig. 1A]Fig. 1A is a perspective view showing an example of an appearance of a
battery according to a first embodiment of the present technology.
[fig.lB]Fig. IB is an exploded perspective view showing an example of a con
figuration of the battery according to the first embodiment of the present technology.
[fig.2A]Fig. 2A is a perspective view showing an example of a shape of a positive
electrode lead provided at an end portion of one side of a winding electrode.
[fig.2B]Fig. 2B is a perspective view showing an example of a shape of a negative
electrode lead provided at an end portion of the other side of the winding electrode
[fig.3A]Fig. 3A is a top view showing an example of a shape of the battery according
to the first embodiment of the present technology.
[fig.3B]Fig. 3B is a cross- sectional view showing an example of a cross-sectional
structure taken along line IIIB-IIIB of Fig. 3A.
[fig.3C]Fig. 3C is a cross- sectional view showing an example of a cross-sectional
structure taken along line IIIC-IIIC of Fig. 3A.
[fig.4]Fig. 4 is a cross-sectional view showing an example of a configuration of a first
and a second sheath material.
[fig.5A]Fig. 5A is top view showing an example of a shape of the winding electrode.
[fig.5B]Fig. 5B is a cross- sectional view representing an example of an enlarged crosssectional
structure of the winding electrode shown in Fig. 5A.
[fig.6A]Fig. 6A is a cross-sectional view showing an example of a cross- sectional
structure taken along line VIA-VIA of Fig. 5A.
[fig.6B]Fig. 6B is a cross- sectional view showing an example of a cross-sectional
structure taken along line VIB-VIB of Fig. 5A.
[fig.7]Fig. 7 is a cross-sectional view showing an example of a cross- sectional
structure taken along line VII-VII of Fig. 5A.
[fig.8A]Fig. 8A is a plan view showing an example of a configuration of the positive
electrode in an unwound state.
[fig.8B]Fig. 8B is a cross- sectional view showing an example of a cross-sectional
structure taken along line VIIIB-VIIIB of Fig. 8A.
[fig.9A]Fig. 9A is a plan view showing an example of a configuration of the positive
electrode on which a protective layer is provided.
[fig.9B]Fig. 9B is a cross- sectional view showing an example of a cross-sectional
structure taken along line IXB-IXB of Fig. 9A.
[fig.9C]Fig. 9C is a cross- sectional view showing another example of a configuration
of the positive electrode on which the protective layer is provided
[fig. 1OA]Fig. 10A is a plan view showing an example of a configuration of the
negative electrode in the unwound state.
[fig.lOB]Fig. 10B is a cross- sectional view showing an example of a cross-sectional
structure taken along line XB-XB of Fig. 10A.
[fig. 11A]Fig. 11A is a process diagram for illustrating an example of a manufacturing
method of the battery according to the first embodiment of the present technology
[fig. 1lB]Fig. 1IB is a process diagram for illustrating an example of the manu
facturing method of the battery according to the first embodiment of the present
technology.
[fig. 1lC]Fig. 11C is a process diagram for illustrating an example of the manu
facturing method of the battery according to the first embodiment of the present
technology.
[fig. 1lD]Fig. 1ID is a process diagram for illustrating an example of the manu
facturing method of the battery according to the first embodiment of the present
technology.
[fig.l2A]Fig. 12A is a process diagram for illustrating an example of the manu
facturing method of the battery according to the first embodiment of the present
technology.
[fig.l2B]Fig. 12B is a process diagram for illustrating an example of the manu
facturing method of the battery according to the first embodiment of the present
technology.
[fig.l3A]Fig. 13A is a perspective view showing an example of an appearance of a
battery according to a first modification example of the first embodiment of the present
technology.
[fig.l3B]Fig. 13B is a cross- sectional view showing an example of a cross-sectional
structure taken along line XIIIB-XIIIB of Fig. 13A.
[fig.l3C]Fig. 13C is a cross- sectional view showing an example of a cross-sectional
structure taken along line XIIIC-XIIIC of Fig. 13A.
[fig.l4A]Fig. 14A is an exploded perspective view showing an example of a con
figuration of a battery according to a second modification example of the first em
bodiment of the present technology.
[fig.l4B]Fig. 14B is a cross- sectional view showing an example of a configuration of
the battery according to the second modification example of the first embodiment of
the present technology.
[fig.l5]Fig. 15 is a cross-sectional view showing an example of a configuration of a
battery according to a third modification example of the first embodiment of the
present technology.
[fig. 16A]Fig. 16A is a perspective view showing a first example of an appearance of a
battery according to a fourth modification example of the first embodiment of the
present technology.
[fig.l6B]Fig. 16B is an exploded perspective view showing the first example of a con
figuration of the battery according to the fourth modification example of the first em
bodiment of the present technology.
[fig.l7A]Fig. 17A is a perspective view showing a second example of an appearance
of the battery according to the fourth modification example of the first embodiment of
the present technology.
[fig.l7B]Fig. 17B is a perspective view showing a third example of an appearance of
the battery according to the fourth modification example of the first embodiment of the
present technology.
[fig.l8A]Fig. 18A is a plan view showing an example of a configuration of a sheath
material of a battery according to a fifth modification example of the first embodiment
of the present technology.
[fig.l8B]Fig. 18B is a cross- sectional view showing an example of a cross-sectional
structure taken along line XVIIIB-XVIIIB of Fig. 18A.
[fig. 19A]Fig. 19A is a plan view showing another example of a configuration of the
sheath material of the battery according to the fifth modification example of the first
embodiment of the present technology.
[fig.l9B]Fig. 19B is a cross- sectional view showing an example of a cross-sectional
structure taken along line XIXB-XIXB of Fig. 19A.
[fig.20A]Fig. 20A is a block diagram showing an example of a configuration of an
electronic device according to a second embodiment of the present technology.
[fig.20B]Fig. 20B is a block diagram showing an example of a configuration of an
electronic device according to a modification example of the second embodiment of
the present technology.
Description of Embodiments
[0012] The embodiments of the present technology will be described in the following order.
1. First Embodiment (example of battery)
1.1 Configuration of Battery
1.2 Manufacturing Method of Battery
1.3 Effect
1.4 Modification Example
2. Second Embodiment (example of assembled battery)
2.1 Configuration of Electronic Device
2.2 Modification Example
First Embodiment
[0013] (1.1 Configuration of Battery)
[0014] Fig. 1A shows an example of an appearance of a battery according to a first em
bodiment of the present technology. Fig. IB shows an example of a configuration of
the battery according to the first embodiment of the present technology. The battery is
a so-called lithium ion secondary battery, and is equipped with a substantially
cylindrical shape winding electrode 1 having a hollow portion in the center, a sheath
material 2 having flexibility which sheathes the winding electrode 1, and a positive
electrode lead 3a and a negative electrode lead 4a which are electrically connected to
the outer peripheral portion of the winding electrode 1. The sheath material 2 has a
substantially cylindrical shape space portion, and the winding electrode 1 is housed in
the space portion. Then, a joining portion 23 such as a heat fusion portion is provided
so as to surround the four sides of the winding electrode 1 that is housed in the space
portion.
[0015] Hereinafter, the positive electrode lead 3a and the negative electrode lead 4a, the
sheath material 2, and the winding electrode 1 configuring the battery will be se
quentially described.
Positive Electrode Lead and Negative Electrode Lead
[0016] The end portion of one side of the positive electrode lead 3a is electrically connected
to the outer periphery of the end portion of one side of the winding electrode 1, and the
other end of the positive electrode lead 3a is led out to the outside of the sheath
material 2 from the end portion of one side of the winding electrode 1. The sheath
material 2 is joined by sandwiching the positive electrode lead 3a at the end portion
side of one side of the winding electrode 1. Meanwhile, one end of the negative
electrode lead 4a is electrically connected to the outer periphery of the end portion of
the other side of the winding electrode 1, and the other end of the negative electrode
lead 4a is led out to the outside of the sheath material 2 from the end portion of the
other side of the winding electrode 1. The sheath material 2 is joined by sandwiching
the negative electrode lead 4a at the end portion side of the other side of the winding
electrode 1.
[0017] Fig. 2A shows an example of a shape of a positive electrode lead 3a provided at the
end portion of one side of the winding electrode 1. The positive electrode lead 3a is
bent substantially perpendicularly to an end surface ISa at the center of the end surface
ISa of one side of the winding electrode 1, and is led out to the outside of the sheath
material 2. The positive electrode lead 3a has a connecting portion 3 1 which is elec
trically connected to the outermost peripheral portion of the positive electrode included
in the winding electrode 1, a bent portion 32 which is bent so as to follow the end
surface ISa of one side of the winding electrode 1, and a led-out portion 33 which is
led out in the direction substantially perpendicular to the end surface ISa. At the
portion that is sandwiched between the sheath material 2 of the led-out portion 33, a
sealant material 3b such as a heat fusion sealing material is provided. Thus, it is
possible to improve adhesiveness between the positive electrode lead 3a led out from
the sheath material 2 and the inner side surface of the sheath material 2.
[0018] Fig. 2B shows an example of a shape of the negative electrode lead 4a provided at
the end portion of the other side of the winding electrode 1. The negative electrode
lead 4a is bent substantially perpendicularly to an end surface ISb at the center of the
end surface ISb of the other side of the winding electrode 1, and is led out to the
outside of the sheath material 2. The negative electrode lead 4a has a connecting
portion 4 1 which is electrically connected to the outermost peripheral portion of the
negative electrode included in the winding electrode 1, a bent portion 42 which is bent
so as to follow the end surface ISb of one side of the winding electrode 1, and a ledout
portion 43 which is led out in the direction substantially perpendicular to the end
surface ISb. At the portion that is sandwiched between the sheath material 2 of the ledout
portion 43, a sealant material 4b such as a heat fusion sealing material is provided.
Thus, it is possible to improve adhesiveness between the negative electrode lead 4a led
out from the sheath material 2 and the inner side surface of the sheath material 2.
[0019] The positive electrode lead 3a and the negative electrode lead 4a, for example, are
configured with a metal material such as aluminum, copper, nickel, or stainless steel.
Each of the sealant materials 3b and 4b is configured with a material having adhe
siveness with the positive electrode lead 3a and the negative electrode lead 4a, for
examples, a polyolefin resin such as polyethylene, polypropylene, modified
polyethylene, or modified polypropylene.
[0020] Each of the positive electrode lead 3a and the negative electrode lead 4a has a thin
plate shape or a net shape having a principal surface 3S or 4S. The principal surfaces
3S and 4S of the positive electrode lead 3a and the negative electrode lead 4a and the
joining portion 23 in a state of being erected substantially perpendicularly to the end
surface ISa or lSb of the winding electrode 1 and the peripheral surface preferably
have a substantially parallel relationship. This is because joining of the sheath material
2 at both end sides of the winding electrode 1 becomes easier.
[0021] When viewing the winding electrode 1 from the direction perpendicular to the end
surface ISa or the end surface lSb, the connecting portion 3 1 of the positive electrode
lead 3a and the connecting portion 4 1 of the negative electrode lead 4a, for example,
are provided at the position of being overlapped, or are provided at the position facing
the peripheral surface of the winding electrode 1. Moreover, in Fig. IB, an example of
the former is shown.
[0022] As described above, in a case where the connecting portions 3 1 and 4 1 are provided
at the position of being overlapped, the connecting portions 3 1 and 4 1 are preferably
provided so as not to be overlapped on the peripheral surface of the winding electrode
1. More specifically, each of the lengths La and Lb of the connecting portions 3 1 and
4 1 of the positive electrode lead 3a and the negative electrode lead 4a is preferably a
half or less of the length (height) L of the winding electrode 1 ((La/2) and (Lb/2) are
equal to or less than L). This is because it is possible to prevent deformation of the
winding electrode 1 due to overlapping of the connecting portions 3 1 and 41, and it is
possible to improve the roundness of the cross-sectional shape of the winding electrode
1. Here, as shown in Figs. 2A and 2B, the length L of the winding electrode 1 and the
lengths La and Lb of the connecting portions of the positive electrode lead 3a and the
negative electrode lead 4a mean the lengths in the direction of the central axis O.
Sheath Material
[0023] The sheath material 2 is equipped with a first sheath material 2 1 and a second sheath
material 22. For example, the first sheath material 2 1 and the second sheath material 22
are formed of a rectangular film having flexibility. As the film, a laminated film is
preferably used. The first sheath material 2 1 and the second sheath material 22 have
substantially the same shapes. Specifically, the first sheath material 2 1 has a first space
portion 21a of a substantially semicylindrical shape provided on a principal surface of
one side, and a peripheral portion 21b provided so as to surround the four sides of the
first space portion 21a. On the other hand, the second sheath material 22 has a second
space portion 22a of a substantially semicylindrical shape provided on a principal
surface of one side, and a peripheral portion 22b provided so as to surround the four
sides of the second space portion 22a. Here, the semicylindrical shape refers to a shape
in which a circular column is divided into two in the axial direction, so-called a
cylindrical shape. Hereinafter, among both principal surfaces of the first sheath
material 2 1 and the second sheath material 22, the principal surface of the side on
which the winding electrode 1 is housed, that is, the principal surface of the less than
the first space portion 21a and the second space portion 22a are provided, is appro
priately referred to as a housing surface.
[0024] In the state of superimposing the housing surfaces of the first sheath material 2 1 and
the second sheath material 22 such that both face each other, the peripheral portions
21b and 22b thereof are disposed so as to surround the four sides of the winding
electrode 1, and the peripheral portions are joined by the heat fusion portion or the like.
Thus, a substantially cylindrical shape space portion is formed between the first sheath
material 2 1 and the second sheath material 22. As described above, the substantially
cylindrical shape winding electrode 1 is housed in the space portion. The space portion
preferably has substantially the same size as the winding electrode 1. This is because in
a state in which the winding electrode 1 is housed in the sheath material 2, it is possible
to increase adhesiveness between them.
[0025] Fig. 3A shows an example of a shape of the battery according to the first em
bodiment of the present technology. Fig. 3B shows an example of a cross- sectional
structure taken along line IIIB-IIIB shown in Fig. 3A. Fig. 3C shows an example of a
cross- sectional structure taken along line IIIC-IIIC shown in Fig. 3A. The positive
electrode lead 3a is provided at the position facing any bottom portion of the first space
portion 21a and the second space portion 22a in the outermost peripheral portion of the
positive electrode included in the winding electrode 1. On the other hand, the negative
electrode lead 4a is provided at the position facing any bottom portion of the first space
portion 21a and the second space portion 22a in the outermost peripheral portion of the
negative electrode included in the winding electrode 1.
[0026] The joining portion 23 provided around the winding electrode 1 is equipped with
short side joining portions 24Wa and 24Wb provided at both end sides of the winding
electrode 1 and peripheral surface side joining portions 25La and 25Lb provided at the
peripheral surface side of the winding electrode 1. The peripheral surface side joining
portions 25La and 25Lb are provided at the position facing the central axis of the
winding electrode 1. In Figs. 1A and IB and Figs. 3A to 3C, examples in which the
short side joining portions 24Wa and 24Wb are erected substantially perpendicularly to
the end surface ISa or lSb, and the peripheral surface side joining portions 25La and
25Lb are erected substantially perpendicular to the peripheral surface are shown.
However, the shapes of the short side joining portions 24Wa and 24Wb, and the p e
ripheral surface side joining portions 25La and 25Lb are not limited thereto. For
example, the short side joining portions 24Wa and 24Wb and the peripheral surface
side joining portions 25La and 25Lb may be modified by being curved or bent. For
example, the positive electrode lead 3a and the negative electrode lead 4a are provided
at the positions at 90 degrees in the clockwise direction or the counter-clockwise
direction based on the positions at which the short side joining portion 24Wa and
24Wb are provided, on the peripheral surface of the winding electrode 1.
[0027] Fig. 4 is a cross-sectional view showing an example of a configuration of the first
sheath material 2 1 and the second sheath material 22. For example, the first sheath
material 2 1 and the second sheath material 22 are laminated films having moisture re
sistance and an insulating property, and have laminated structures in which a heat
fusion resin layer 5 1 which is a first resin layer, a metal layer 52, and a surface
protective layer 53 which is a second resin layer are laminated in this order. The sheath
material 2 may be further equipped with an adhesive layer 54 between the heat fusion
resin layer 5 1 and the metal layer 52, if necessary. In addition, an adhesive layer 55
may be further equipped between the metal layer 52 and the surface protective layer
53. Moreover, the surface of the heat fusion resin layer 5 1 side becomes a housing
surface of the side housing the winding electrode 1.
[0028] As the material of the heat fusion resin layer 51, resins which are fusible by heat or
ultrasonic waves are preferably used. As such resins, polyolefin-based resins such as
polypropylene (PP) and polyethylene (PE) are preferably used, and for example, unstretched
polypropylene (CPP) is used. In a case of sealing the periphery of the
winding electrode 1 by applying heat to the first sheath material 2 1 and the second
sheath material 22, the material of the heat fusion resin layer 51 is melted, and thus the
peripheries of the first sheath material 2 1 and the second sheath material 22 are joined.
[0029] The metal layer 52 is one that plays a role of preventing the entry of moisture,
oxygen, and light, and protecting the winding electrode 1 which is content. As the
material of the metal layer 52, from the viewpoint of lightness, extensibility, price, and
ease of processing, for example, metal foils formed of aluminum (Al) or an aluminum
alloy is used.
[0030] The surface protective layer 53 is intended for protecting the surfaces of the first
sheath material 2 1 and the second sheath material 22. As the material of the surface
protective layer 53, from the viewpoint of aesthetics, toughness, and flexibility, for
example, nylon (Ny) or polyethylene terephthalate (PET) is used.
[0031] As the material of the adhesive layers 54 and 55, for example, adhesives formed of a
urethane resin, an acrylic resin, or a styrene resin can be used.
[0032] Moreover, the first sheath material 2 1 and the second sheath material 22 are not
limited to those having the above-described structures. For example, as the first sheath
material 2 1 and the second sheath material 22, laminate films having a structure
different from the structures described above, polymer films such as polypropylene, or
metal films may be used. In addition, as the first sheath material 2 1 and the second
sheath material 22, from the viewpoint of aesthetics, sheath materials which are further
equipped with a colored layer, and/or include a coloring material in at least one kind
selected from among the heat fusion resin layer 51, the surface protective layer 53, and
the adhesive layers 54 and 55 may be used. More specifically, sheath materials which
are further equipped with a colored layer on the surface of the surface protective layer
53, include a colorant in the adhesive layers 54 between the metal layer 52 and the
surface protective layer 53, and include a colorant in the surface protective layer 53
itself may be used.
[0033] The thickness of the first sheath material 2 1 and the second sheath material 22 at the
end surface side of the winding electrode 1 may be different from the thickness of the
first sheath material 2 1 and the second sheath material 22 at the peripheral surface side
of the winding electrode 1. More specifically, for example, the thickness of the first
sheath material 2 1 and the second sheath material 22 at the end surface side of the
winding electrode 1 may be thinner compared to the thickness of the first sheath
material 2 1 and the second sheath material 22 at the peripheral surface side of the
winding electrode 1.
[0034] In a case where the first sheath material 2 1 and the second sheath material 22 have
laminated structures including metal layers, the thickness of the metal layers at the end
surface side of the winding electrode 1 may be different from the thickness of the
metal layers at the peripheral surface side of the winding electrode 1. More
specifically, for example, the thickness of the metal layers at the end surface side of the
winding electrode 1 may be thinner compared to the thickness of the metal layers at the
end surface side of the winding electrode 1.
[0035] The thickness of the first sheath material 2 1 and the second sheath material 22 at the
end surface side of the winding electrode 1 and metal layers included therein can be
measured, for example, in the following manner. First, by an FIB (Focused Ion Beam)
processing, a cross- section of the first sheath material 2 1 and the second sheath
material 22 is cut out, in the direction perpendicular to the fusion surface of the first
sheath material 2 1 and the second sheath material 22, so as to include the central axis
of the winding electrode 1. Next, the cross-section is observed using TEM
(Transmission Electron Microscope), and the thickness of the first sheath material 2 1
and the second sheath material 22 on the end surface side of the winding electrode 1
and metal layers included therein is determined.
[0036] The thickness of the first sheath material 2 1 and the second sheath material 22 on the
peripheral surface side of the winding electrode 1 and metal layers included therein can
be measured, for example, in the following manner. First, by the FIB processing, a
cross- section of the first sheath material 2 1 and the second sheath material 22 is cut out
in the direction perpendicular to the central axis of the winding electrode 1, so as to
include the central axis of the winding electrode 1. Next, the cross-section is observed
using TEM, and the thickness of the first sheath material 2 1 and the second sheath
material 22 at the peripheral surface side of the winding electrode 1 and metal layers
included therein is determined.
Winding Electrode
[0037] Fig. 5A shows an example of a shape of the winding electrode 1. Winding stop
portions 5a and 5b which are intended for stopping winding of the winding electrode 1
are provided on the peripheral surface of the winding electrode 1. The winding stop
portions 5a and 5b cover one turn or more of the peripheral surface of the winding
electrode 1, and preferably cover at least both end portions of the peripheral surface of
the winding electrode 1. This is because it is possible to suppress deformation of the
winding electrode 1 due to charging and discharging. As the winding stop portions 5a
and 5b, for example, a rectangular tape or the like can be used, however, there is no
limitation thereto. In Fig. 5A, an example in which both ends of the peripheral surface
of the winding electrode 1 are winding-stopped by the two winding stop portions 5a
and 5b is shown, however, the number of the winding stop portions and the ar
rangement positions of the winding stop portions are not limited thereto. For example,
the number of the winding stop portions may be one, or three or greater. In addition,
the arrangement positions of the winding stop portions may be central portions of the
peripheral surface of the winding electrode 1. In addition, the winding number of the
winding stop portions 5a and 5b wound on the peripheral surface of the winding
electrode 1 is not limited to one turn or more, and it is also possible to be less than one
turn.
[0038] Fig. 5B represents an example of an enlarged cross- sectional structure of the winding
electrode 1 shown in Fig. 5A. Fig. 6A shows an example of a cross-sectional structure
taken along line VIA-VIA of Fig. 5A. Fig. 6B shows an example of a cross-sectional
structure taken along line VIB-VIB of Fig. 5A. The winding electrode 1 is equipped
with a positive electrode 11, a negative electrode 12, a separator 13, and an electrolyte
layer 14, and the positive electrode 11, the negative electrode 12, and the separator 13
have, for example, an elongated rectangular shape. The winding electrode 1 has a
winding structure in which the positive electrode 11 and the negative electrode 12
through the separator 13 are wound in a longitudinal direction thereof. For example,
the winding electrode 1 is wound such that both the outermost peripheral electrode and
the innermost peripheral electrode become the negative electrode 12. Between the
positive electrode 11 and the separator 13, and the negative electrode 12 and the
separator 13, the electrolyte layer 14 is provided. Moreover, in Figs. 5A and 5B, in
order to facilitate understanding of the winding structure of the positive electrode 11,
the negative electrode 12, and the separator 13, the electrolyte layer 14 is not shown.
[0039] The separator 13 is folded on the inner peripheral side of the winding electrode 1 so
as to sandwich the negative electrode 12. Both ends in the longitudinal direction of the
separator 13 cover the outer periphery of the winding electrode 1, and are positioned at
the outermost periphery of the winding electrode 1. More specifically, both ends in the
longitudinal direction of the separator 13 cover the outermost periphery of the positive
electrode 11 and the negative electrode 12, in the outer periphery of the winding
electrode 1 such that the positive electrode 11 and the negative electrode 12 are not
exposed. For example, the separator 13 is wound one turn or longer than the end
portions of the positive electrode 11 and the negative electrode 12. The positive
electrode lead 3a and the negative electrode lead 4a are provided at the outermost
periphery of each of the positive electrode 11 and the negative electrode 12. The
positive electrode 11 is disposed on the outside of the separator 13 folded at the inner
peripheral side.
[0040] The winding electrode 1 has a substantially cylindrical shape, and a hollow portion
l h in the center thereof. The width D of the hollow portion l h is the width of a hollow
portion formed on the inner side surface of the innermost peripheral electrode which is
positioned at the hollow portion lh. For example, the width D of the hollow portion l h
is 2.5 mm or less, preferably 2 mm or less, and more preferably 1.5 mm or less. Here,
the width D of the hollow portion l h means a width D of the hollow portion l h in the
direction perpendicular to the central axis of the cylindrical shape winding electrode 1.
In a case where the width D of the hollow portion l h varies depending on the direction,
a width having a maximum value among widths of the hollow portion l h is defined as
the width D of the hollow portion lh. For example, the hollow portion l h is sub
stantially cylindrical shape space. In a case where the hollow portion l h is a sub
stantially cylindrical shape, the width D of the hollow portion l h is the diameter
thereof.
[0041] Fig. 7 shows an example of a cross-sectional structure taken along line VII- VII of
Fig. 5A. The width Wb in the short direction of the separator 13 is narrower than the
width Wa in the short direction of the positive electrode 11 and the negative electrode
12, and both ends in the short direction of the separator 13 are preferably positioned
closer to the outside than both ends in the short direction of the positive electrode 11
and the negative electrode 12. In a case of employing such a configuration, both ends
in the short direction of the separator 13 are preferably bent in the direction of the
central axis of the winding electrode 1. This is because it is possible to improve safety
by covering both ends in the short direction of the positive electrode 11 and the
negative electrode 12 by the separator 13. In addition, in a case of employing the
above-described configuration, at both ends in the short direction of the separator 13,
the end portions of the separator 13 adjacent to the radial direction of the winding
electrode 1 may be joined to each other by fusion or the like. In this case, the joined
portion may be bent in the direction of the central axis of the winding electrode 1.
[0042] Fig. 8A shows an example of a configuration of the positive electrode 11 in an
unwound state. Fig. 8B shows an example of a cross-sectional structure taken along
line VIIIB-VIIIB shown in Fig. 8A. For example, the positive electrode 11 is equipped
with a positive electrode current collector 11A and a positive electrode active material
layer 1IB provided on both surfaces of the positive electrode current collector 11A.
Moreover, although not shown, the positive electrode active material layer 11B may be
provided on only one surface of the positive electrode current collector 11A.
[0043] One end in the longitudinal direction of the positive electrode 11 becomes the inner
peripheral side of the winding electrode 1, and the other end in the longitudinal
direction of the positive electrode 11 becomes the outer peripheral side of the winding
electrode 1. A positive electrode current collector-exposed portion 11C is provided at
the other end of the positive electrode 11 which becomes the outer peripheral side, and
the positive electrode current collector-exposed portion 11C is not provided at one end
of the positive electrode 11 which becomes the inner peripheral side, but the positive
electrode active material layer 1IB is provided to the tip. For example, the positive
electrode current collector-exposed portion 11C is provided on both surfaces of the
other end of the positive electrode 11. The positive electrode lead 3a is provided at the
exposed portion of a surface which becomes the outer peripheral side in the positive
electrode current collector-exposed portion 11C provided at both surfaces thereof. The
sealant material 3b is preferably provided away from the long side of the positive
electrode 1 1 so as not to overlap with the positive electrode current collector-exposed
portion 11C.
[0044] As shown in Figs. 9A and 9B, the protective layer 15 which covers the positive
electrode current collector-exposed portion 11C to which the positive electrode lead 3a
is electrically connected is preferably further provided. In addition, as shown in Fig.
9C, the end portion of the positive electrode active material layer 1IB is preferably
covered with the protective layer 15. As the protective layer 15, for example, a
protective tape or the like can be used.
[0045] Fig. 10A shows an example of a configuration of the negative electrode 12 in the
unwound state. Fig. 10B shows an example of a cross-sectional structure taken along
line XB-XB shown in Fig. 10A. For example, the negative electrode 12 is equipped
with a negative electrode current collector 12A and the negative electrode active
material layer 12B provided on both surfaces of a negative electrode current collector
12A. Moreover, although not shown, the negative electrode active material layer 12B
may be provided on only one surface of the negative electrode current collector 12A.
[0046] One end in the longitudinal direction of the negative electrode 12 becomes the inner
peripheral side of the winding electrode 1, and the other end in the longitudinal
direction of the negative electrode 12 becomes the outer peripheral side of the winding
electrode 1. A negative electrode current collector-exposed portion 12C is provided at
the other end of the negative electrode 12 which becomes the outer peripheral side, and
the negative electrode current collector-exposed portion 12C is not provided at one end
of the negative electrode 12 which becomes the inner peripheral side, but the negative
electrode active material layer 12B is provided to the tip. For example, the negative
electrode current collector-exposed portion 12C is provided on both surfaces of the
other end of the negative electrode 12. The negative electrode lead 4a is provided at the
exposed portion of a surface which becomes the outer peripheral side in the negative
electrode current collector-exposed portion 12C provided at both surfaces thereof. The
protective layer is preferably further provided also in the negative electrode current
collector-exposed portion 12C in the same manner as in the positive electrode current
collector-exposed portion 11C. The sealant material 4b is preferably provided away
from the long side of the negative electrode 12 so as not to overlap with the negative
electrode current collector-exposed portion 12C.
[0047] As described above, it is possible to reduce the size of the winding electrode 1 by
providing the positive electrode lead 3a and the negative electrode lead 4a at the
outermost periphery of each of the positive electrode 11 and the negative electrode 12.
In addition, it is possible to further reduce the size of the winding electrode 1 by
providing each of the positive electrode current collector-exposed portion 11C and the
negative electrode current collector-exposed portion 12C at only the end portion of the
outermost periphery side of the positive electrode 11 or negative electrode 12.
[0048] The tip positions of the positive electrode active material layer 1IB and the negative
electrode active material layer 12B in the longitudinal direction of the winding
electrode 1 may correspond to the radial direction of the winding electrode 1. In
addition, the tip positions of the positive electrode active material layer 1IB and the
negative electrode active material layer 12B in the short direction of the positive
electrode 11 and the negative electrode 12 may correspond to the radial direction of the
winding electrode 1.
[0049] The positive electrode 11 and the negative electrode 12 are preferably thin electrodes.
Thus, even when the edge positions of the positive electrode active material layer 1IB
and the negative electrode active material layer 12B are lined up in the radial direction
of the winding electrode 1, it is possible to obtain the excellent safety. The thickness of
the positive electrode 1 1 is preferably 150 micrometers or less, more preferably 120
micrometers or less, and even more preferably 60 micrometers or greater and 110 mi
crometers or less. The thickness of the negative electrode 12 is preferably 150 mi
crometers or less, more preferably 120 micrometers or less, and even more preferably
60 micrometers or greater and 110 micrometers or less.
[0050] For example, the positive electrode current collector 11A is configured with a metal
foil such as aluminum foil, nickel foil, or stainless steel foil. For example, the positive
electrode active material layer 1IB includes one kind or two or more kinds of the
positive electrode material capable of occluding and releasing lithium as the positive
electrode active material, and is configured to include a conductive agent such as
graphite and a binder such as polyvinylidene fluoride, if necessary.
[0051] As the positive electrode material capable of occluding and releasing lithium, for
example, lithium-containing compounds such as lithium oxide, lithium phosphorus
oxide, lithium sulfide, or an intercalation compound including lithium are appropriate,
and two or more kinds thereof may be used in combination. In order to increase the
energy density, lithium-containing compounds including lithium, a transition metal
element, and oxygen (O) are preferable. Examples of such a lithium-containing
compound include a lithium composite oxide having a layered rock-salt type structure
shown in the formula (A) and a lithium composite oxide having an olivine type
structure shown in the formula (B). The lithium-containing compound more preferably
includes at least one kind of the group formed of cobalt (Co), nickel (Ni), manganese
(Mn), and iron (Fe) as a transition metal element. Examples of such a lithiumcontaining
compound include a lithium composite oxide having a layered rock-salt
type structure shown in the formula (C), (D), or (E), a lithium composite oxide having
a spinel type structure shown in the formula (F), or a lithium composite oxide having
an olivine type structure shown in the formula (G), and specific examples thereof
include LiNio.50Coo.20Mno.30O2, Li Co0 2 (a is approximately equal to 1), LibNi0 2(b is
approximately equal to 1), LiclNiC2Co 1 C20 2 (cl is approximately equal to 1, c2 is greater
than 0 and less than 1), LidMn20 4 (d is approximately equal to 1), or LLFeP0 4 (e is ap
proximately equal to 1).
[0052] LipNi l rMn Ml rO 2_y X ... (A)
(In the formula (A), Ml represents at least one kind among elements selected from
Group 2 to Group 15 excluding nickel (Ni) and manganese (Mn). X represents at least
one kind among elements of Groups 16 and 17 excluding oxygen (O). p, q, y, and z are
values in the range in which p is equal to or greater than 0 and equal to or less than 1.5,
q is equal to or greater than 0 and equal to or less than 1.0, r is equal to or greater than
0 and equal to or less than 1.0, y is equal to or greater than -0. 10 and equal to or less
than 0.20, and z is equal to or greater than 0 and equal to or less than 0.2.)
[0053] Li M2bP0 4 ... (B)
(In the formula (B), M2 represents at least one kind among elements selected from
Group 2 to Group 15. a and b are values in the range in which a is equal to or greater
than 0 and equal to or less than 2.0 and b is equal to or greater than 0.5 and equal to or
less than 2.0.)
[0054] LifMn l h Ni M3 O 2j Fk ... (C)
(In the formula (C), M3 represents at least one kind among the group formed of
cobalt (Co), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V),
chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), zirconium (Zr), molybdenum (Mo),
tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). f, g, h, j , and k are values in
the range in which f is equal to or greater than 0.8 and equal to or less than 1.2, g is
equal to or greater than 0 and equal to or less than 0.5, h is equal to or greater than 0
and equal to or less than 0.5, g + h is less than 1, j is equal to or greater than -0.1 and
equal to or less than 0.2, and k is equal to or greater than 0 and equal to or less than
0.1. Moreover, the composition of lithium varies depending upon the state of charge
and discharge, and the value of f represents a value in a completely discharged state.)
[0055] Li Ni l M4 O 2 p F ... (D)
(In the formula (D), M4 represents at least one kind among the group formed of
cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium
(Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum
(Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). m, n, p, and q are
values in the range in which m is equal to or greater than 0.8 and equal to or less than
1.2, n is equal to or greater than 0.005 and equal to or less than 0.5, p is equal to or
greater than -0.1 and equal to or less than 0.2, and q is equal to or greater than 0 and
equal to or less than 0.1. Moreover, the composition of lithium varies depending upon
the state of charge and discharge, and the value of m represents a value in a completely
discharged state.)
[0056] LirCo(l s M5sO 2 t F ... (E)
(In the formula (E), M5 represents at least one kind among the group formed of
nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium
(Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum
(Mo), tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). r, s, t, and u are values
in the range in which r is equal to or greater than 0.8 and equal to or less than 1.2, s is
equal to or greater than 0 and equal to or less than 0.5, t is equal to or greater than -0.1
and equal to or less than 0.2, and u is equal to or greater than 0 and equal to or less
than 0.1. Moreover, the composition of lithium varies depending upon the state of
charge and discharge, and the value of r represents a value in a completely discharged
state.)
[0057] Li Mn wM6wO F ... (F)
(In the formula (F), M6 represents at least one kind among the group formed of
cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti),
vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo),
tin (Sn), calcium (Ca), strontium (Sr), and tungsten (W). v, w, x, and y are values in the
range in which v is equal to or greater than 0.9 and equal to or less than 1. 1, w is equal
to or greater than 0 and equal to or less than 0.6, x is equal to or greater than 3.7 and
equal to or less than 4.1, and y is equal to or greater than 0 and equal to or less than
0.1. Moreover, the composition of lithium varies depending upon the state of charge
and discharge, and the value of v represents a value in a completely discharged state.)
[0058] Li M7P0 4 ... (G)
(In the formula (G), M7 represents at least one kind among the group formed of
cobalt (Co), manganese (Mn), iron (Fe), nickel (Ni), magnesium (Mg), aluminum (Al),
boron (B), titanium (Ti), vanadium (V), niobium (Nb), copper (Cu), zinc (Zn),
molybdenum (Mo), calcium (Ca), strontium (Sr), tungsten (W), and zirconium (Zr). z
is a value in the range in which z is equal to or greater than 0.9 and equal to or less
than 1.1. Moreover, the composition of lithium varies depending upon the state of
charge and discharge, and the value of z represents a value in a completely discharged
state.)
[0059] As the positive electrode material capable of occluding and releasing lithium, in
addition to these, inorganic compounds such as Mn0 2, V20 5, V60 i3, NiS, and MoS
which do not contain lithium can also be used.
[0060] The positive electrode material capable of occluding and releasing lithium may be
materials other than those described above. In addition, the positive electrode materials
exemplified above may be mixed in any combination of two or more kinds thereof.
[0061] For example, the negative electrode current collector 12A is configured with a metal
foil such as copper foil, nickel foil, or stainless steel foil. The negative electrode active
material layer 12B is configured to include one kind or two or more kinds of the
negative electrode material capable of occluding and releasing lithium as the negative
electrode active material, and is configured to include the same binder as in the
positive electrode active material layer 11B, if necessary.
[0062] Moreover, in this battery, the electrochemical equivalent of the negative electrode
material capable of occluding and releasing lithium is greater than the electrochemical
equivalent of the positive electrode 11, and a lithium metal is not deposited on the
negative electrode 12 during charging.
[0063] As the negative electrode material capable of occluding and releasing lithium, for
example, carbon materials such as hardly graphitizable carbon, easily graphitizable
carbon, graphite, pyrolytic carbon, coke, glassy carbon, an organic polymer compound
fired material, carbon fiber, or activated carbon can be exemplified. As the graphite,
natural graphite which was subjected to a spheroidization processing and substantially
spherically shaped artificial graphite are preferably used. As the artificial graphite, ar
tificial graphite obtained by graphitizing meso-carbon microbeads (MCMB) or ar
tificial graphite obtained by graphitizing coke raw material and pulverizing is
preferable. As the coke, pitch coke, needle coke, petroleum coke, or the like can be ex
emplified. The organic polymer compound fired material refers to one obtained by
firing polymeric material such as a phenol resin and a furan resin at an appropriate
temperature to carbonize, and in part, some are classified as hardly graphitizable
carbon, or easily graphitizable carbon. In addition, as the polymer material, polyacetylene
or polypyrrole can be exemplified. These carbon materials are preferable
since change in the crystal structure that occurs during charging and discharging is
very small, it is possible to obtain a high charge and discharge capacity, and it is
possible to obtain excellent cycle characteristics. In particular, graphite is preferable
since an electrochemical equivalent is large, and thus, it is possible to obtain a high
energy density. In addition, the hardly graphitizable carbon is preferable since
excellent characteristics can be obtained. In addition, materials of which charge and
discharge potential are low, in particular, materials of which the charge and discharge
potential are close to those of the lithium metal, are preferable since it is possible to
easily realize a high energy density of the battery.
[0064] As the negative electrode material capable of occluding and releasing lithium,
materials which are capable of occluding and releasing lithium and include at least one
kind among metal elements and metalloid elements as a constituent element can also
be exemplified. Here, the negative electrode 12 including such a negative electrode
material is referred to as an alloy-based negative electrode. This is because if using
such a material, it is possible to obtain a high energy density. In particular, if using
such a material together with the carbon material, it is possible to obtain a high energy
density, and it is possible to obtain excellent cycle characteristics, and therefore, it is
more preferable. The negative electrode material may be a simple substance, an alloy,
or a compound of a metal element or a metalloid element, and may also have one kind
or two or more kinds of phases thereof in at least a part. Moreover, the alloy in the
present technology also includes an alloy containing one or more kind of metal
elements and one or more kinds of metalloid elements in addition to an alloy formed of
two or more kinds of metal elements. In addition, a nonmetallic element may be
included. In the structure, a solid solution, eutectic crystal (eutectic mixture), an intermetallic
compound, or two or more kinds of these coexist.
[0065] Examples of the metal element or the metalloid element configuring the negative
electrode material include magnesium (Mg), boron (B), aluminum (Al), gallium (Ga),
indium (In), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), bismuth (Bi), cadmium
(Cd), silver (Ag), zinc (Zn), hafnium (Hf), zirconium (Zr), yttrium (Y), palladium (Pd),
and platinum (Pt). These may be crystalline or amorphous.
[0066] Among these, as the negative electrode material, materials including a metal element
of Group 4B in the short-form periodic table or a metalloid element as a constituent
element are preferable, and materials including at least one of silicon (Si) and tin (Sn)
as a constituent element are particularly preferable. This is because silicon (Si) and tin
(Sn) have great abilities of occluding and releasing lithium (Li), and thus, it is possible
to obtain a high energy density.
[0067] As the tin (Sn) alloy, tin (Sn) alloys including at least one of the group formed of
silicon (Si), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese (Mn), zinc
(Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony
(Sb), and chromium (Cr) as a second constituent element other than tin (Sn) can be ex
emplified. As the silicon (Si) alloy, silicon (Si) alloys including at least one of the
group formed of tin (Sn), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), manganese
(Mn), zinc (Zn), indium (In), silver (Ag), titanium (Ti), germanium (Ge), bismuth (Bi),
antimony (Sb), and chromium (Cr) as a second constituent element other than silicon
(Si) can be exemplified.
[0068] As the compound of tin (Sn) or the compound of silicon (Si), compounds including
oxygen (O) or carbon (C) can be exemplified, and in addition to tin (Sn) or silicon (Si),
may also include the second constituent element described above.
[0069] As the negative electrode material capable of occluding and releasing lithium, fur
thermore, other metal compounds or polymer materials can be exemplified. As the
other metal compounds, oxides such as Mn0 2, V20 5, and V60 i3, sulfides such as NiS
and MoS, or lithium nitrides such as LiN3 can be exemplified, and as the polymer
materials, polyacetylene, polyaniline, polypyrrole, or the like can be exemplified.
[0070] The separator 13 isolates the positive electrode 1 1 and the negative electrode 12, and
thus prevents a short circuit of current due to contact of both electrodes, and passes
lithium ions. For example, the separator 13 is configured with porous films made of a
synthetic resin such as polytetrafluoroethylene, polypropylene, or polyethylene, or
porous films made of ceramic, and has a structure in which these two or more porous
film are laminated. Among these, a porous film made of polyolefin has an excellent
short circuit prevention effect, and can improve safety of a battery by a shutdown
effect, and therefore, it is preferable. In particular, by using polyethylene, it is possible
to obtain the shutdown effect within the temperature range of 100 degrees Celsius or
higher and 160 degrees Celsius or lower, and polyethylene also has excellent electro
chemical stability, and therefore it is preferable as the material configuring the
separator 13. In addition, polypropylene is also preferable, and also, if a resin has
chemical stability, it is possible to use the resin by copolymerizing or blending the
resin with polyethylene or polypropylene.
[0071] The electrolyte layer 14 includes a non-aqueous electrolytic solution and a polymer
compound which is a holding member for holding the non-aqueous electrolytic
solution, and the polymer compound is swollen by the non-aqueous electrolytic
solution. The content ratio of the polymer compound can be appropriately adjusted. In
particular, in a case where the electrolyte is a gel-like electrolyte, it is possible to
obtain high ion conductivity, and it is possible to prevent the fluid leakage of the
battery, and therefore it is preferable.
[0072] For example, the non-aqueous electrolytic solution includes a solvent and an
electrolyte salt. Examples of the solvent include ordinary temperature molten salts such
as 4-fluoro-l,3-dioxolan-2-one, ethylene carbonate, propylene carbonate, butylene
carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl
carbonate, gamma-butyrolactone, gamma-valerolactone, 1,2-dimethoxyethane, tetrahydrofuran,
2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-l,3-dioxolane, methyl
acetate, methyl propionate, ethyl propionate, acetonitrile, glutaronitrile, adiponitrile,
methoxyacetonitrile, 3-methoxypropionitrile, N,N-dimethylformamide, Nmethylpyrrolidinone,
N-methyloxazolidinone, nitromethane, nitroethane, sulfolane,
dimethyl sulfoxide, trimethyl phosphate, triethyl phosphate, ethylene sulfite, and bistrifluoromethyl
sulfonylimide trimethylhexyl ammonium. Among these, by using in
combination at least one of the group formed of 4-fluoro-l,3-dioxolan-2-one, ethylene
carbonate, propylene carbonate, vinylene carbonate, dimethyl carbonate, ethyl methyl
carbonate, and ethylene sulfite, it is possible to obtain excellent charge and discharge
capacity characteristics and excellent charge and discharge cycle characteristics, and
therefore it is preferable. In order to improve the battery characteristics, the electrolyte
layer 14 may contain existing additives.
[0073] The electrolyte salt may include a mixture of one or two or more materials. Examples
of the electrolyte salt include lithium hexafluorophosphate (LiPF ), lithium
bis(pentafluoroethanesulfonyl) imide (Li(C2F5S0 2)2N), lithium perchlorate (LiC104),
lithium hexafluoroarsenate (LiAsF ), lithium tetrafluoroborate (LiBF4), lithium trifluoromethanesulfonate
(LiS0 3CF3), lithium bis(trifluoromethanesulfonyl) imide (Li (CF3
S0 2)2N), lithium tris(trifluoromethanesulfonyl) methide (LiC(S0 2CF3)3), lithium
chloride (LiCl), and lithium bromide (LiBr).
[0074] Examples of the polymer compound include polyacrylonitrile, polyvinylidene
fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene,
polyhexafluoropropylene, polyethylene oxide, polypropylene oxide,
polyphosphazene, polysiloxane, polyvinyl acetate, polyvinyl alcohol, polymethyl
methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrilebutadiene
rubber, polystyrene, or polycarbonate. In particular, from the viewpoint of
electrochemical stability, polyacrylonitrile, polyvinylidene fluoride, polyhexafluoro
propylene, or polyethylene oxide is preferable.
(1.2 Manufacturing Method of Battery)
[0075] Hereinafter, an example of the manufacturing method of the battery according to the
first embodiment of the present technology will be described with reference to Figs.
8A, 8B, and 10A to 12B.
[0076] First, for example, a positive electrode mixture is prepared by mixing a positive
electrode active material, a conductive agent, and a binder, and this positive electrode
mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone, whereby a paste-like
positive electrode mixture slurry is produced. Next, this positive electrode mixture
slurry is coated on the positive electrode current collector 11A and dried, and the
resultant product is compression-molded using a roll press machine or the like to form
the positive electrode active material layer 1IB, whereby the positive electrode 11 is
formed.
[0077] In addition, for example, a negative electrode mixture is prepared by mixing a
negative electrode active material and a binder, and this negative electrode mixture is
dispersed in a solvent such as N-methyl-2-pyrrolidone, whereby a paste-like negative
electrode mixture slurry is produced. Next, this negative electrode mixture slurry is
coated on the negative electrode current collector 12A and dried, and the resultant
product is compression-molded using a roll press machine or the like to form the
negative electrode active material layer 12B, whereby the negative electrode 12 is
produced.
[0078] Next, a precursor solution including a solvent, an electrolyte salt, a polymer
compound, and a mixed solvent is coated on each of the positive electrode 11 and the
negative electrode 12, and the mixed solvent is volatilized, whereby the electrolyte
layer 14 is formed. Next, as shown in Figs. 8A and 8B, the positive electrode lead 3a is
electrically connected to the positive electrode current collector-exposed portion 11C
of the positive electrode 11. Next, as shown in Figs. 10A and 10B, the negative
electrode lead 4a is electrically connected to the negative electrode current collectorexposed
portion 12C of the negative electrode 12. As the connection method, ul
trasonic welding, resistance welding, and soldering can be exemplified, and in con
sideration of the damage of the connecting portion by heat, methods in which thermal
effects by the ultrasonic welding or the resistance welding are small are preferably
used.
[0079] Next, as shown in Fig. 11A, a substantially central position in the longitudinal
direction of the separator 13 is inserted into a gap 101a of a winding core 101, and is
sandwiched by the winding core 101. Next, as shown in Fig. 1IB, by rotating the
winding core 101 in the direction indicated by an arrow 102a, the separator 13 is
wound on the peripheral surface of the winding core 101. Next, the negative electrode
12 is supplied between the separator 13 folded from a substantially middle position
from the direction indicated by an arrow 102b. Thus, the negative electrode 12 is
dragged between the separator 13 by the rotation of the winding core 101.
[0080] Next, as shown in Fig. 11C, the positive electrode 11 is supplied between the
separator 13 from the direction indicated by an arrow 102c such that the positive
electrode 1 1 and the negative electrode 12 are overlapped through the separator 13.
Thus, the positive electrode 11 is dragged between the separator 13 by the rotation of
the winding core 101. At this time, the supplying position of the positive electrode 11
is preferably adjusted such that the tip positions in the longitudinal direction of the
positive electrode 1 1 and the negative electrode 12 are matched. Next, as shown in Fig.
1ID, by maintaining the rotation of the winding core 101, the positive electrode 11, the
negative electrode 12, and the separator 13 are wound a predetermined number of
times. Thus, the winding electrode 1 is obtained.
[0081] Next, as shown in Fig. 12A, the housing surfaces of the first sheath material 2 1 and
the second sheath material 22 are overlapped such that the winding electrode 1 is
housed in the first space portion 21a of the first sheath material 2 1 and the second
space portion 22a of the second sheath material 22. Next, as shown in Fig. 12B, the p e
ripheral portions 21b of the first sheath material 2 1 and the peripheral portions 22b of
the second sheath material 22 are joined by heat fusion or the like. Thus, the joining
portion 23 is formed around the winding electrode 1, and the winding electrode 1 is
sealed by the first sheath material 2 1 and the second sheath material 22. Thus, the
battery of interest can be obtained.
(1.3 Effect)
[0082] In the battery according to the first embodiment, since the winding electrode 1 of
which the width of the hollow portion lh is 2 mm or less is housed in the film-like
sheath material 2 having flexibility, it is possible to realize a battery having small size
and being light in weight. In addition, since the battery has the positive electrode lead
3a and the negative electrode lead 4a, it is possible to easily connect the battery to a
circuit of an electronic device or the like. In addition, in a case where attaching each of
the positive electrode lead 3a and the negative electrode lead 4a to the outermost
periphery of the positive electrode 11 and the negative electrode 12 included in the
winding electrode 1, it is possible to further miniaturize the winding electrode 1.
(1.4 Modification Examples)
[0083] (Modification Example 1)
[0084] Fig. 13A shows an example of an appearance of a battery according to a first modi
fication example of the first embodiment of the present technology. Fig. 13B shows an
example of a cross-sectional structure taken along line XIIIB-XIIIB of Fig. 13A. Fig.
13C shows an example of a cross- sectional structure taken along line XIIIC-XIIIC of
Fig. 13A. The peripheral surface side joining portions 25La and 25Lb provided at the
peripheral surface side of the winding electrode 1 may be bent so as to follow the p e
ripheral surface of the winding electrode 1. In this case, the cross-sectional shape of the
battery perpendicular to the central axis of the winding electrode 1 is a substantially
circular shape. Therefore, it is possible to further miniaturize the battery.
[0085] Both of the positive electrode lead 3a and the negative electrode lead 4a are
preferably provided on any side of a half peripheral surface which is housed in the first
space portion 21a and a half peripheral surface plane which is housed in the second
space portion 22a of the peripheral surface of the winding electrode 1. In this case, the
peripheral surface side joining portions 25La and 25Lb are preferably provided so as to
follow the half peripheral surface of the side opposite to the side on which the positive
electrode lead 3a and the negative electrode lead 4a are provided. More specifically,
the peripheral surface side joining portions 25La and 25Lb are preferably bent so as to
follow the peripheral surface in the direction of the ridge line of the half peripheral
surface of the side opposite to the side on which the positive electrode lead 3a and the
negative electrode lead 4a are provided. This is because it is possible to improve the
roundness of the cross-sectional shape of the battery. Here, the half peripheral surface
refers to a surface formed by dividing the peripheral surface of the winding electrode 1
into two in the axial direction thereof.
(Modification Example 2)
[0086] Figs. 14A and 14B show an example of a configuration of a battery according to a
second modification example of the first embodiment of the present technology. The
battery according to the second modification 2 is different from the battery according
to the first embodiment in the point that both of the positive electrode lead 3a and the
negative electrode lead 4a are led out to the outside of the sheath material 2 from the
end portion of one side of the winding electrode 1. In the modification example 2, the
same places as in the first embodiment will be given the same reference numerals, and
their descriptions will not be repeated.
[0087] The sheath material 60 has a substantially cylindrical shape space portion of which
one end is open, and the winding electrode 1 is housed in the space portion. At the
open end portion of the space portion, a sheath material 26 is provided as a lid, and by
this, the sheath material 60 is sealed. The sheath materials 26 and 60 are joined by
sandwiching the positive electrode lead 3a and the negative electrode lead 4a at the end
portion side of one side of the winding electrode 1. At the part of the positive electrode
lead 3a and the negative electrode lead 4a which is sandwiched by the sheath materials
26 and 60, the sealant materials 3b and 4b are preferably provided. As the sheath
materials 26 and 60, the same laminated film as the sheath material 2 in the first em
bodiment described above can be used. The positive electrode lead 3a and the negative
electrode lead 4a are preferably provided at the position not overlapping with the
joining portion provided at the peripheral surface side of the winding electrode 1 in the
outermost periphery of the winding electrode 1. For example, the positive electrode
lead 3a and the negative electrode lead 4a are provided at the positions that are sym
metrical about the central axis of the winding electrode 1.
[0088] The sheath material 60 is equipped with a first sheath material 6 1 and a second
sheath material 62. The first sheath material 6 1 has a first space portion 61a provided
on the principal surface of one side, and a peripheral portion 61b provided at the
periphery of the first space portion 61a. The second sheath material 62 has a second
space portion 62a provided on the principal surface of one side, and a peripheral
portion 62b provided at the periphery of the second space portion 62a. The first space
portion 61a and the second space portion 62a have substantially semicylindrical
shapes, and the end portion of one side thereof is open. Each of the peripheral portions
61b and 62b has a letter-U shape, and are provided so as to surround the three sides of
the first space portion 61a and the second space portion 62a. The sheath material 26 as
a lid has a substantially circular shape, and at the peripheral portion thereof, the joining
portion for being joined with the sheath material 60 is provided.
(Modification Example 3)
[0089] Fig. 15 is a cross-sectional view showing an example of a configuration of a battery
according to a third modification example of the first embodiment of the present
technology. In the first embodiment, the positive electrode lead 3a and the negative
electrode lead 4a may be led out to the outside of the sheath material 2 from the end
portion of one side of the winding electrode 1. In this case, the first sheath materials 2 1
and 22 are joined by sandwiching the positive electrode lead 3a and the negative
electrode lead 4a at the end portion side of one side of the winding electrode 1. An in
sulating member 7 1 is provided between the positive electrode lead 3a and the negative
electrode lead 4a led out to prevent electrical contact therebetween. As the insulating
member, for example, an adhesive sheet having an insulating property or the like can
be used. At the part of the positive electrode lead 3a and the negative electrode lead 4a
which is sandwiched by the first sheath material 2 1 and the second sheath material 22,
the sealant materials 3b and 4b are preferably provided.
(Modification Example 4)
[0090] An example of the battery according to a fourth modification example of the first em
bodiment of the present technology will be described with reference to Figs. 16A to
17B. In the first embodiment described above, an example in which the positive
electrode lead 3a and the negative electrode lead 4a are led out to the outside of the
sheath material 2 from both ends of the winding electrode 1, that is, the joining
portions of the short sides of the sheath material 2, is shown, however, the led-out d i
rections of the positive electrode lead 3a and the negative electrode lead 4a are not
limited to this example. For example, as shown in Figs. 16A and 17A, the positive
electrode lead 3a and the negative electrode lead 4a may be led out from the joining
portions of the long sides of the sheath material 2.
[0091] In Fig. 16A, an example in which the positive electrode lead 3a and the negative
electrode lead 4a are led out to the outside of the sheath material 2 from the joining
portions of the different long sides of the sheath material 2 is shown. In Fig. 16B, an
example in which the positive electrode lead 3a and the negative electrode lead 4a are
led out to the outside of the sheath material 2 from the joining portions of the same
long sides of the sheath material 2 is shown. In a case of employing such a con
figuration, as shown in Fig. 16B, one end of the positive electrode lead 3a and the
negative electrode lead 4a is electrically connected so as to follow the peripheral
surface of the winding electrode 1, and the other end thereof is led out to the outside of
the sheath material 2 which is erected in the direction substantially perpendicular to the
peripheral surface of the winding electrode 1.
[0092] In addition, as shown in Fig. 17B, the electrode of one side of the positive electrode
lead 3a and the negative electrode lead 4a may be led out to the outside of the sheath
material 2 from the joining portions of the short sides of the sheath material 2, and the
electrode of the other side thereof may be led out to the outside of the sheath material 2
from the joining portions of the long sides of the sheath material 2.
(Modification Example 5)
[0093] Fig. 18A shows an example of a configuration of a sheath material of a battery
according to a fifth modification example of the first embodiment of the present
technology. Fig. 18B shows an example of a cross-sectional structure taken along line
XVIIIB-XVIIIB of Fig. 18A. The battery according to the fifth modification example
is different from the battery according to the first embodiment in the point that the first
space portion 21a and the second space portion 22a are provided in one sheath material
81. The sheath material 8 1 has an elongated rectangular shape, and in the center, a
folding portion 81a for folding the sheath material 8 1 in the longitudinal direction is
provided. At the folding portion 81a, for example, a notch extended in the short
direction of the sheath material 8 1 is provided. The first space portion 21a is provided
on a housing surface of one side of the sheath material 8 1 to be folded, and the second
space portion 22a is provided on a housing surface of the other side. Moreover, in Figs.
18A and 18B, an example in which the first space portion 21a and the second space
portion 22a are provided some distance away in the longitudinal direction is shown,
however, the first space portion 21a and the second space portion 22a may be provided
to be adjacent to each other.
[0094] In addition, as shown in Figs. 19A and 19B, the first space portion 21a and the
second space portion 22a may be provided in parallel with each other in the sheath
material 82. In this case, a folding portion 82a is provided between the first space
portion 21a and the second space portion 22a arranged in parallel with each other. The
folding portion 82a is extended in the ridge line direction of the first space portion 21a
and the second space portion 22a of a substantially semicylindrical shape.
(Modification Example 6)
[0095] The battery according to the first embodiment may be produced as described below.
First, as described above, the positive electrode 1 1 and the negative electrode 12 are
produced, and the positive electrode lead 3a and the negative electrode lead 4a are
attached to the positive electrode 11 and the negative electrode 12, respectively. Next,
the positive electrode 11 and the negative electrode 12 through the separator 13 are
laminated and wound, and a protective tape is stuck to the outermost periphery portion,
whereby a winding body which is a precursor of the winding electrode 1 is formed.
Next, the winding body is sandwiched between the sheath material 2, the outer p e
ripheral portion excluding one side is made in a bag shape by heat fusion, and the
winding body is accommodated in the sheath material 2. Next, a composition for an
electrolyte including a solvent, an electrolyte salt, a monomer which is a raw material
of a polymer compound, a polymerization initiator, and, if necessary, other materials
such as a polymerization inhibitor is prepared, and the composition is injected in the
sheath material 2.
[0096] Next, after injecting the composition for electrolyte in the sheath material 2, the
opening portion of the sheath material 2 is heat-fused to be sealed in a vacuum at
mosphere. Next, by forming a polymer compound by polymerizing the monomers by
applying heat, a gel-like electrolyte layer 14 is formed. Thus, the battery of interest can
be obtained.
(Modification Example 7)
[0097] The battery according to the first embodiment may be produced as described below.
In this producing method, the winding electrode 1 is produced in the same manner as
in the modification example 6 described above except for using the separator 13 of
which both sides are coated with the polymer compound, and is accommodated in the
bag-like sheath material 2. For example, the polymer compound which is coated on the
separator 13 is a polymer (homopolymer, copolymer, or multi-component copolymer)
which has vinylidene fluoride as the component, or the like. Specifically, binary
copolymers which have polyvinylidene fluoride, vinylidene fluoride, or hexafluoropropylene
as the component, or ternary copolymers which have vinylidene fluoride,
hexafluoropropylene, or chlorotrifluoroethylene as the component can be exemplified.
Moreover, one or two or more kinds of other polymer compounds may be used
together with a polymer which has vinylidene fluoride as the component. Next, after an
electrolytic solution is prepared and the electrolytic solution is injected in the sheath
material 2, the opening portion of the sheath material 2 is sealed by a heat fusion
method. Subsequently, heating is performed while a weight is applied to the sheath
material 2, and the separator 13 is brought into close contact with the positive electrode
11 and the negative electrode 12 through the polymer compound. Thus, the electrolytic
solution is impregnated into the polymer compound, and the polymer compound is
gelled, whereby the electrolyte layer 14 is formed.
(Modification Example 8)
[0098] In the first embodiment described above, an example using a gel-like electrolyte was
described, however, an electrolytic solution which is an liquid electrolyte may be used
instead of the gel-like electrolyte. In this case, for example, the battery may be
produced as described below. First, a winding body which is a precursor of the
winding electrode 1 is formed in the same manner as in the modification example 6.
Next, the winding body is sandwiched between the sheath material 2, the outer p e
ripheral portion excluding one side is made in a bag shape by heat fusion, and the
winding body is accommodated in the sheath material 2. Next, an electrolytic solution
is prepared, and the electrolytic solution is injected into the sheath material 2, and after
the electrolytic solution is impregnated into the winding body, the opening portion of
the sheath material 2 is heat-fused to be sealed in a vacuum atmosphere. Thus, the
battery of interest can be obtained.
Second Embodiment
[0099] (2. 1 Configuration of Electronic Device)
[0100] Fig. 20A is a block diagram showing an example of a configuration of an electronic
device according to a second embodiment of the present technology. An electronic
device 400 is equipped with an electronic circuit 401 of an electronic device main body
and a battery pack 300. The battery pack 300 is electrically connected to the electronic
circuit 401. For example, the electronic device 400 has a configuration in which the
battery pack 300 can be attached and detached by the user. Moreover, the con
figuration of the electronic device 400 is not limited thereto, and may be a con
figuration in which the battery pack 300 is built into the electronic device 400 such that
the battery pack 300 may not be removed from the electronic device 400 by the user.
[0101] When charging the battery pack 300, each of a positive electrode terminal 331a and a
negative electrode terminal 331b of the battery pack 300 is connected to a positive
electrode terminal and a negative electrode terminal of the charger (not shown). In
contrast, when discharging the battery pack 300 (when using the electronic device
400), each of the positive electrode terminal 331a and the negative electrode terminal
331b of the battery pack 300 is connected to the positive electrode terminal and the
negative electrode terminal of the electronic circuit 401.
[0102] For example, the electronic device 400 is a portable electronic device. The electronic
device 400 may be a wearable electronic device.
Electronic Circuit
[0103] For example, the electronic circuit 401 is equipped with a CPU, a peripheral logic
portion, an interface portion, memory portion, and the like, and controls the entirety of
the electronic device 400.
Battery Pack
[0104] The battery pack 300 is equipped with a secondary battery 301 and a charging and
discharging circuit 302. As the secondary battery 301, any battery in the first em
bodiment and the modification examples 1 to 8 described above can be used.
[0105] When charging, the charging and discharging circuit 302 controls the charging with
respect to the secondary battery 301. In contrast, when discharging (when using the
electronic device 400), the charging and discharging circuit 302 controls discharging
with respect to the electronic device 400.
(2.2 Modification Examples)
[0106] Fig. 2IB is a block diagram showing an example of a configuration of an electronic
device according to a modification example of the second embodiment of the present
technology. In the second embodiment, an assembled battery 310 may be used. The
assembled battery 310 is configured by electrically connecting a plurality of the
secondary batteries 301 in at least one of parallel and series. For example, the plurality
of the secondary batteries 301 are connected n in parallel and m in series (n and m are
positive integers). When the plurality of the secondary batteries 301 are electrically
connected, for example, the positive electrode lead 3a and the negative electrode lead
4a are used (for example, see Fig. 1A). Moreover, in Fig. 20B, an example in which six
secondary batteries 301 are connected 2 in parallel and 3 in series (2P3S) is shown.
[0107] The embodiments according to the present technology are described in detail above,
but the present technology is not limited to the embodiments described above and
various modifications can be made based on the technical idea behind the present
technology.
[0108] For example, the configurations, methods, processes, shapes, materials, and
numerical values exemplified in the above-described embodiments are only examples,
and configurations, methods, processes, shapes, materials, and numerical values
different from these may be used if necessary.
[0109] In addition, the configurations, methods, processes, shapes, materials, and numerical
values in the above-described embodiments can be combined with each other without
departing from the scope of the present technology.
[01 10] In addition, the present technology can also employ the following configurations.
(1) A battery equipped with a substantially cylindrical shape winding electrode
having a hollow portion in the center, and a sheath material having flexibility which
sheathes the winding electrode, in which a width of the hollow portion is 2.5 mm or
less.
(2) The battery according to (1) further equipped with a positive electrode lead and a
negative electrode lead provided at an outer peripheral portion of the winding
electrode.
(3) The battery according to (2), in which the positive electrode lead is led out to the
outside of the sheath material from an end portion of one side of the winding electrode,
and the negative electrode lead is led out to the outside of the sheath material from an
end portion of the other side of the winding electrode.
(4) The battery according to (3), in which the sheath material is joined by sandwiching
the positive electrode lead at an end portion side of one side of the winding electrode,
and is joined by sandwiching the negative electrode lead at an end portion side of the
other side of the winding electrode.
(5) The battery according to (2), in which both of the positive electrode lead and the
negative electrode lead are led out to the outside of the sheath material from the end
portion of one side of the winding electrode.
(6) The battery according to (5), in which the sheath material is joined by sandwiching
the positive electrode lead and the negative electrode lead at the end portion side of
one side of the winding electrode.
(7) The battery according to any one of (2) to (6), in which the sheath material is
equipped with a first joining portion and a second joining portion provided at a p e
ripheral surface side of the winding electrode, the positive electrode lead and the
negative electrode lead are provided on a first half peripheral surface of a peripheral
surface of the winding electrode, and the first joining portion and the second joining
portion are provided so as to follow a second half peripheral surface of the peripheral
surface of the winding electrode.
(8) The battery according to any one of (2) to (7), in which the positive electrode lead
and the negative electrode lead are bent substantially perpendicularly to an end surface
at the center of the end surface of the winding electrode, and are led out to the outside
of the sheath material.
(9) The battery according to any one of (1) to (8), in which the winding electrode is
equipped with a positive electrode, a negative electrode, and a separator, and the
separator is folded at an inner peripheral side of the winding electrode.
(10) The battery according to any one of (1) to (9), in which the sheath material is a
laminated film.
(11) The battery according to any one of (1) to (9), in which the sheath material has a
film shape.
(12) The battery according to any one of (1) to ( 11), in which a thickness of the sheath
material at an end surface side of the winding electrode and a thickness of the sheath
material at the peripheral surface side of the winding electrode are different.
(13) The battery according to any one of (1) to (12), in which the sheath material is
equipped with a first sheath material having a first space portion of a substantially
semicylindrical shape and a second sheath material having a second space portion of a
substantially semicylindrical shape, a substantially cylindrical shape space portion is
configured with the first space portion and the second space portion, and the winding
electrode is provided in the space portion.
(14) The battery according to (13), in which each of the positive electrode lead and the
negative electrode lead is provided at a position facing a bottom portion of the first
space portion or the second space portion in the outer peripheral portion of the winding
electrode.
(15) The battery according to any one of (1) to (14), in which the winding electrode is
equipped with the positive electrode, the negative electrode, and the separator, and
both ends in a width direction of the separator are positioned closer to the outside than
both ends in a width direction of the positive electrode and the negative electrode.
(16) The battery according to (15), in which the separator is fused at an end portion of
the winding electrode.
(17) The battery according to any one of (1) to (16), in which the winding electrode is
equipped with the positive electrode and the negative electrode, and thicknesses of the
positive electrode and the negative electrode are 150 micrometers or less.
(18) The battery according to any one of (1) to (17), in which the winding electrode is
equipped with an electrolyte including an electrolytic solution and a polymer
compound.
(19) The battery according to any one of (1) to (18) further equipped with a winding
stop portion covering one turn or more of the peripheral surface of the winding
electrode, in which the winding stop portion covers at least both end portions of the p e
ripheral surface of the winding electrode.
(20) An assembled battery which is equipped with the battery according to any one of
(1) to (19).
(21) An electronic device which is equipped with the battery according to any one of
(1) to (19).
In addition, the present technology can also employ the following configurations.
(1) A battery, comprising:
a substantially cylindrically shaped winding electrode having a hollow portion in the
center; and
a sheath material having flexibility which sheathes the winding electrode,
wherein a width of the hollow portion is 2.5 mm or less.
(2) The battery according to (1), wherein the hollow portion is substantially cylindrically
shaped with a diameter of 2.5 mm or less that extends along a central axis of
the winding electrode.
(3) The battery according to (1), further comprising:
a positive electrode lead and a negative electrode lead both provided at an outer p e
ripheral portion of the winding electrode.
(4) The battery according to (3),
wherein the positive electrode lead is led out to the outside of the sheath material from
an end portion of one side of the winding electrode, and
the negative electrode lead is led out to the outside of the sheath material from an end
portion of the other side of the winding electrode.
(5) The battery according to (4),
wherein the sheath material is joined by sandwiching the positive electrode lead at an
end portion side of one side of the winding electrode, and is joined by sandwiching the
negative electrode lead at an end portion side of the other side of the winding
electrode.
(6) The battery according to (3),
wherein both of the positive electrode lead and the negative electrode lead are led out
to the outside of the sheath material from the end portion of one side of the winding
electrode.
(7) The battery according to (6),
wherein the sheath material is joined by sandwiching the positive electrode lead and
the negative electrode lead at the end portion side of one side of the winding electrode.
(8) The battery according to (3),
wherein the sheath material is equipped with a first joining portion and a second
joining portion provided at a peripheral surface side of the winding electrode,
the positive electrode lead and the negative electrode lead are provided on a first half
peripheral surface side of a peripheral surface of the winding electrode, and
the first joining portion and the second joining portion are provided so as to follow a
second half peripheral surface of the peripheral surface of the winding electrode.
(9) The battery according to (3),
wherein the positive electrode lead and the negative electrode lead are bent sub
stantially perpendicularly to an end surface at the center of the end surface of the
winding electrode, and are led out to the outside of the sheath material.
(10) The battery according to (1),
wherein the winding electrode is equipped with a positive electrode, a negative
electrode, and a separator, and
the separator is folded at an inner peripheral side of the winding electrode.
(11) The battery according to (1),
wherein the winding electrode is equipped with a positive electrode, a negative
electrode, and a separator, and
wherein ends of the separator are provided at an outer peripheral side of the winding
electrode.
(12) The battery according to (1),
wherein the sheath material is a laminated film.
(13) The battery according to (1),
wherein the sheath material has a film shape.
(14) The battery according to (1),
wherein a thickness of the sheath material at an end surface side of the winding
electrode and a thickness of the sheath material at the peripheral surface side of the
winding electrode are different from each other.
(15) The battery according to (1),
wherein the sheath material is equipped with
a first sheath material having a first space portion of a substantially semicylindrical
shape,
a second sheath material having a second space portion of a substantially semicylindrical
shape, and
a substantially cylindrical shape space portion is configured with the first space portion
and the second space portion, and the winding electrode is provided in the space
portion.
(16) The battery according to (5),
wherein each of the positive electrode lead and the negative electrode lead is provided
at a position facing a bottom portion of the first space portion or the second space
portion in the outer peripheral portion of the winding electrode.
(17) The battery according to (1),
wherein the winding electrode is equipped with the positive electrode, the negative
electrode, and the separator, and
both ends in a width direction of the separator are positioned closer to the outside than
both ends in a width direction of the positive electrode and the negative electrode.
(18) The battery according to (17),
wherein the separator is fused at an end portion of the winding electrode.
(19) The battery according to (1),
wherein the winding electrode is equipped with the positive electrode and the negative
electrode, and
thicknesses of the positive electrode and the negative electrode are 150 micrometers or
less.
(20) The battery according to (1),
wherein the winding electrode is equipped with an electrolyte including an electrolytic
solution and a polymer compound.
(21) The battery according to (1), further comprising:
a winding stop portion covering one turn or more of the peripheral surface of the
winding electrode,
wherein the winding stop portion covers at least both end portions of the peripheral
surface of the winding electrode.
(22) An assembled battery, comprising:
a plurality of batteries electrically connected in at least one of parallel and series,
wherein the batteries are equipped with a substantially cylindrically shaped winding
electrode having a hollow portion in the center and a sheath material having flexibility
which sheathes the winding electrode, and a width of the hollow portion is 2.5 mm or
less.
(23) The assembled battery according to (22), wherein the hollow portion is sub
stantially cylindrically shaped with a diameter of 2.5 mm or less that extends along a
central axis of the winding electrode.
(24) A method of manufacturing a winding electrode for a battery, the method
comprising:
inserting a separator into a gap of a winding core;
winding the winding core to wind two portions of the separator around an outer p e
ripheral surface of the winding core;
wherein at least one electrode is stacked on the separator and
removing the winding core to leave a hollow portion in a central portion of the winding
electrode,
wherein the winding electrode is substantially cylindrically shaped, and
wherein the hollow portion is substantially cylindrically shaped with a diameter of 2.5
mm or less that extends along a central axis of the winding electrode.
[01 12] It should be understood by those skilled in the art that various modifications, com
binations, sub-combinations and alterations may occur depending on design re
quirements and other factors insofar as they are within the scope of the appended
claims or the equivalents thereof.
Reference Signs List
[0113] 1 Winding electrode
2 Sheath material
3a Positive electrode lead
3b Negative electrode lead
a, 4b Sealant material
5a, 5b Winding stop portion
11 Positive electrode
11A Positive electrode current collector
11B Positive electrode active material layer
llC Positive electrode current collector-exposed portion
12 Negative electrode
12A Negative electrode current collector
12B Negative electrode active material layer
12C Negative electrode current collector-exposed portion
13 Separator
14 Electrolyte layer
15 Protective layer
1 First sheath material
1a First space portion
2 Second sheath material
2a Second space portion
PCT/JP2014/005791

Claims
A battery, comprising:
a substantially cylindrically shaped winding electrode having a hollow
portion in the center; and
a sheath material having flexibility which sheathes the winding
electrode,
wherein a width of the hollow portion is 2.5 mm or less.
The battery according to Claim 1, wherein the hollow portion is sub
stantially cylindrically shaped with a diameter of 2.5 mm or less that
extends along a central axis of the winding electrode.
The battery according to Claim 1, further comprising:
a positive electrode lead and a negative electrode lead both provided at
an outer peripheral portion of the winding electrode.
The battery according to Claim 3,
wherein the positive electrode lead is led out to the outside of the
sheath material from an end portion of one side of the winding
electrode, and
the negative electrode lead is led out to the outside of the sheath
material from an end portion of the other side of the winding electrode.
The battery according to Claim 4,
wherein the sheath material is joined by sandwiching the positive
electrode lead at an end portion side of one side of the winding
electrode, and is joined by sandwiching the negative electrode lead at
an end portion side of the other side of the winding electrode.
The battery according to Claim 3,
wherein both of the positive electrode lead and the negative electrode
lead are led out to the outside of the sheath material from the end
portion of one side of the winding electrode.
The battery according to Claim 6,
wherein the sheath material is joined by sandwiching the positive
electrode lead and the negative electrode lead at the end portion side of
one side of the winding electrode.
The battery according to Claim 3,
wherein the sheath material is equipped with a first joining portion and
a second joining portion provided at a peripheral surface side of the
winding electrode,
the positive electrode lead and the negative electrode lead are provided
PCT/JP2014/005791
on a first half peripheral surface side of a peripheral surface of the
winding electrode, and
the first joining portion and the second joining portion are provided so
as to follow a second half peripheral surface of the peripheral surface of
the winding electrode.
The battery according to Claim 3,
wherein the positive electrode lead and the negative electrode lead are
bent substantially perpendicularly to an end surface at the center of the
end surface of the winding electrode, and are led out to the outside of
the sheath material.
The battery according to Claim 1,
wherein the winding electrode is equipped with a positive electrode, a
negative electrode, and a separator, and
the separator is folded at an inner peripheral side of the winding
electrode.
The battery according to Claim 1,
wherein the winding electrode is equipped with a positive electrode, a
negative electrode, and a separator, and
wherein ends of the separator are provided at an outer peripheral side of
the winding electrode.
The battery according to Claim 1,
wherein the sheath material is a laminated film.
The battery according to Claim 1,
wherein the sheath material has a film shape.
The battery according to Claim 1,
wherein a thickness of the sheath material at an end surface side of the
winding electrode and a thickness of the sheath material at the p e
ripheral surface side of the winding electrode are different from each
other.
The battery according to Claim 1,
wherein the sheath material is equipped with
a first sheath material having a first space portion of a substantially
semicylindrical shape,
a second sheath material having a second space portion of a sub
stantially semicylindrical shape, and
a substantially cylindrical shape space portion is configured with the
first space portion and the second space portion, and the winding
electrode is provided in the space portion.
PCT/JP2014/005791
The battery according to Claim 5,
wherein each of the positive electrode lead and the negative electrode
lead is provided at a position facing a bottom portion of the first space
portion or the second space portion in the outer peripheral portion of
the winding electrode.
The battery according to Claim 1,
wherein the winding electrode is equipped with the positive electrode,
the negative electrode, and the separator, and
both ends in a width direction of the separator are positioned closer to
the outside than both ends in a width direction of the positive electrode
and the negative electrode.
The battery according to Claim 17,
wherein the separator is fused at an end portion of the winding
electrode.
The battery according to Claim 1,
wherein the winding electrode is equipped with the positive electrode
and the negative electrode, and
thicknesses of the positive electrode and the negative electrode are 150
micrometers or less.
The battery according to Claim 1,
wherein the winding electrode is equipped with an electrolyte including
an electrolytic solution and a polymer compound.
The battery according to Claim 1, further comprising:
a winding stop portion covering one turn or more of the peripheral
surface of the winding electrode,
wherein the winding stop portion covers at least both end portions of
the peripheral surface of the winding electrode.
An assembled battery, comprising:
a plurality of batteries electrically connected in at least one of parallel
and series,
wherein the batteries are equipped with a substantially cylindrically
shaped winding electrode having a hollow portion in the center and a
sheath material having flexibility which sheathes the winding electrode,
and a width of the hollow portion is 2.5 mm or less.
The assembled battery according to Claim 22, wherein the hollow
portion is substantially cylindrically shaped with a diameter of 2.5 mm
or less that extends along a central axis of the winding electrode.
A method of manufacturing a winding electrode for a battery, the
PCT/JP2014/005791
method comprising:
inserting a separator into a gap of a winding core;
winding the winding core to wind two portions of the separator around
an outer peripheral surface of the winding core;
wherein at least one electrode is stacked on the separator and
removing the winding core to leave a hollow portion in a central
portion of the winding electrode,
wherein the winding electrode is substantially cylindrically shaped, and
wherein the hollow portion is substantially cylindrically shaped with a
diameter of 2.5 mm or less that extends along a central axis of the
winding electrode.