TECHNICAL FIELD
Cross-reference to Related Applications
[0001] This application claims priority from Korean Patent
Application No. 10-2020-0036395, filed on March 25, 2020, the
disclosure of which is incorporated by reference herein.
Technical Field
[0002] The present invention relates to unit cell
preparation apparatus and method, and more particularly, to
unit cell preparation apparatus and method which may prevent
a displacement of an electrode from its original position
when the electrode and separator sheets are stacked to form a
unit cell.
BACKGROUND ART
[0003] In general, types of secondary batteries include a
nickel cadmium battery, a nickel hydride battery, a lithium
ion battery, and a lithium ion polymer battery. These
secondary batteries are not only applied and used in small
products such as digital cameras, P-DVDs, MP3Ps, mobile
phones, PDAs, portable game devices, power tools, and E-bikes,
but are also applied and used in large products requiring
high output, such as electric vehicles and hybrid vehicles,
and a power storage device and a power storage device for
backup which store surplus generated power or renewable
energy.
[0004] In order to prepare such a secondary battery, first,
a positive electrode collector and a negative electrode
2
collector are respectively coated with electrode active
material slurries to prepare a positive electrode and a
negative electrode, and the positive electrode and the
negative electrode are then stacked on both sides of a
separator to form an electrode assembly having a
predetermined shape. Then, after the electrode assembly is
accommodated in a battery case and an electrolyte solution is
injected, the battery case is sealed.
[0005] The electrode assembly is classified into various
types. For example, there are a simple stack type in which a
unit cell is not prepared and positive electrodes, separators,
and negative electrodes are simply crossed and continuously
stacked, a lamination & stack type (L&S) in which a unit cell
is first prepared using a positive electrode, a separator,
and a negative electrode and these unit cells are then
stacked, a stack & folding type (S&F) in which a plurality of
electrodes or unit cells are spaced apart and attached to one
surface of a separator sheet having a greater length in one
side and the separator sheet is repeatedly folded in the same
direction from one end, and a Z-folding type that
alternatingly repeats a process in which a plurality of
electrodes or unit cells are alternatingly attached to one
surface and the other surface of a separator sheet having a
greater length in one side and the separator sheet is folded
in a specific direction from one end and then folded in an
opposite direction.
[0006] Among them, in order to prepare the lamination &
stack type (L&S), stack & folding type, or Z-folding type
electrode assembly, first, a unit cell may be prepared. In
general, in order to prepare the unit cell, separators are
3
respectively stacked on upper and lower surfaces of a center
electrode while the center electrode is moved to one side by
a conveyor belt or the like, and thereafter, an upper
electrode is further stacked on an uppermost end. In
addition, in some cases, a lower electrode may be further
stacked on a lowermost end. Then, a laminating process is
performed in which heat and pressure are applied to a stack
in which the electrodes and the separators are stacked.
Since the laminating process is performed, the electrodes and
the separators may be adhered to each other to firmly form a
unit cell.
[0007] However, typically, the electrode and the separator
were not adhered to each other, but were only in contact with
each other until the laminating process was performed on the
stack in which the electrode and the separator were stacked.
Thus, there was a problem in that the electrode was out of
position in a process of transferring the stack to perform
the laminating process. Also, since the laminating process
applies high heat and pressure to the stack, there may be a
problem in that the electrode was damaged. Furthermore,
recently, a separator capable of adhering to the electrode
even with low heat and pressure has been developed, but such
a separator also had a problem in that process efficiency was
reduced while it was not economical due to excessively high
manufacturing costs.
[0008] [Prior Art Documents]
[0009] Korean Patent Application Laid-Open Publication No.
2010-0016619
DISCLOSURE OF THE INVENTION
TECHNICAL PROBLEM
4
[0010] An aspect of the present invention provides unit cell
preparation apparatus and method which may prevent a
displacement of an electrode from its original position when
the electrode and separator sheets are stacked to form a unit
cell.
[0011] The object of the present invention is not limited to
the aforesaid, but other objects not described herein will be
clearly understood by those skilled in the art from
descriptions below.
TECHNICAL SOLUTION
[0012] According to an aspect of the present invention,
there is provided an apparatus for preparing a unit cell
which includes: a lower separator reel from which a lower
separator sheet is unwound; a first nozzle for applying an
adhesive to at least a portion of one surface facing upward
of the unwound lower separator sheet; an upper separator reel
from which an upper separator sheet is unwound; a second
nozzle for applying an adhesive to at least a portion of one
surface facing upward of the unwound upper separator sheet;
and a first nip roll for turning opposite surfaces of the
upper separator sheet upside down so that the one surface of
the upper separator sheet to which the adhesive has been
applied is directed downward and adheres to an upper surface
of a first electrode stably placed on the one surface of the
lower separator sheet.
[0013] Also, the apparatus for preparing a unit cell may
further include a first header which stably places the first
electrode on the one surface of the lower separator sheet to
which the adhesive has been applied.
[0014] Furthermore, the apparatus for preparing a unit cell
5
may further include a first electrode reel from which a first
electrode sheet, which is to be the first electrode, is
unwound.
[0015] Also, the apparatus for preparing a unit cell may
further include a first vision sensor disposed above the
first electrode to photograph the first electrode, before the
first electrode adheres to the upper separator sheet.
[0016] Furthermore, the first nip rolls may be respectively
disposed on opposite surfaces of a first stack, which is
formed by sequentially stacking the lower separator sheet,
the first electrode, and the upper separator sheet, to apply
pressure to the first stack while rotating.
[0017] Also, the apparatus for preparing a unit cell may
further include a third nozzle which applies an adhesive to
at least a portion of the other surface facing upward of the
upper separator sheet.
[0018] Furthermore, the apparatus for preparing a unit cell
may further include second nip rolls respectively disposed on
opposite surfaces of a second stack, which is formed by
sequentially stacking the lower separator sheet, the first
electrode, the upper separator sheet, and a second electrode,
to apply pressure to the second stack while rotating, when
the second electrode is stably placed on the other surface of
the upper separator sheet to which the adhesive has been
applied.
[0019] Also, the apparatus for preparing a unit cell may
further include a second header which stably places the
second electrode on the other surface of the upper separator
sheet to which the adhesive has been applied.
[0020] Furthermore, the apparatus for preparing a unit cell
6
may further include a second electrode reel from which a
second electrode sheet, which is to be the second electrode,
is unwound.
[0021] Also, the apparatus for preparing a unit cell may
further include a second vision sensor disposed above the
second electrode to photograph the second electrode, before
the second electrode is stably placed on the other surface of
the upper separator sheet.
[0022] Furthermore, the apparatus for preparing a unit cell
may further include a cutter for cutting the second stack at
a predetermined interval.
[0023] Also, the apparatus for preparing a unit cell may
further include a third vision sensor disposed on a side of
the first electrode to photograph the first electrode, when
the first electrode adheres to the upper separator sheet.
[0024] Furthermore, the apparatus for preparing a unit cell
may further include a light source disposed above the upper
separator sheet to radiate light toward the upper separator
sheet, when the first electrode adheres to the upper
separator sheet.
[0025] According to another aspect of the present invention,
there is provided a method of preparing a unit cell which
includes: unwinding a lower separator sheet from a lower
separator reel; applying an adhesive by a first nozzle to at
least a portion of one surface facing upward of the unwound
lower separator sheet; stably placing a first electrode on
the one surface of the lower separator sheet to which the
adhesive has been applied; unwinding an upper separator sheet
from an upper separator reel; applying an adhesive by a
second nozzle to at least a portion of one surface facing
7
upward of the unwound upper separator sheet; and turning
opposite surfaces of the upper separator sheet upside down by
a first nip roll so that the one surface of the upper
separator sheet to which the adhesive has been applied is
directed downward and adheres to an upper surface of the
first electrode stably placed on the one surface of the lower
separator sheet.
[0026] Also, in the turning of the opposite surfaces of the
upper separator sheet upside down, the first nip rolls may be
respectively disposed on opposite surfaces of a first stack,
which is formed by sequentially stacking the lower separator
sheet, the first electrode, and the upper separator sheet, to
apply pressure to the first stack while rotating.
[0027] Furthermore, the method may further include applying
an adhesive by a third nozzle to at least a portion of the
other surface facing upward of the upper separator sheet,
after the turning of the opposite surfaces of the upper
separator sheet upside down.
[0028] Also, the method may further include stably placing a
second electrode on the other surface of the upper separator
sheet to which the adhesive has been applied, after the
applying of the adhesive by the third nozzle.
[0029] Furthermore, the method may further include
respectively disposing second nip rolls on opposite surfaces
of a second stack, which is formed by sequentially stacking
the lower separator sheet, the first electrode, the upper
separator sheet, and the second electrode, to apply pressure
to the second stack while rotating, after the stably placing
of the second electrode.
[0030] Also, the method may further include cutting the
8
second stack at a predetermined interval by a cutter, after
the applying of the pressure to the second stack.
[0031] Other specific details of the present invention are
included in the detailed description and drawings.
ADVANTAGEOUS EFFECTS
[0032] According to the embodiments of the present invention,
at least the following effects may be achieved.
[0033] When an electrode and separator sheets are stacked to
prepare a unit cell, a displacement in position of the
electrode may be prevented by applying an adhesive in advance
whenever the electrode is stably placed on the separator
sheet, even if an expensive separator is not used.
[0034] Also, since there is no need to perform a laminating
process, a laminator may be removed, and thus, a volume of an
apparatus for preparing a unit cell may be reduced and a
preparation process may be simplified.
[0035] The effects according to the present invention are
not limited to the contents as exemplified above, but more
various effects are included in the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a flowchart of a method of preparing a unit
cell according to an embodiment of the present invention;
[0037] FIG. 2 is a schematic view of an apparatus for
preparing a unit cell according to an embodiment of the
present invention;
[0038] FIG. 3 is a schematic side view illustrating in
detail the apparatus for preparing a unit cell according to
the embodiment of the present invention;
[0039] FIG. 4 is a schematic plan view illustrating in
detail the apparatus for preparing a unit cell according to
9
the embodiment of the present invention;
[0040] FIG. 5 is a schematic view of an apparatus for
preparing a unit cell according to another embodiment of the
present invention; and
[0041] FIG. 6 is a schematic side view illustrating in
detail the apparatus for preparing a unit cell according to
the another embodiment of the present invention.
MODE FOR CARRYING OUT THE INVENTION
[0042] Advantages and features of the present invention, and
implementation methods thereof will be clarified through
following embodiments described with reference to the
accompanying drawings. The present invention may, however,
be embodied in different forms and should not be construed as
limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
present invention to those skilled in the art. Further, the
present invention is only defined by scopes of claims. Like
reference numerals refer to like elements throughout.
[0043] Unless defined otherwise, all terms (including
technical and scientific terms) used herein may be intended
to have meanings understood by those skilled in the art. In
addition, terms defined in general dictionaries should not be
interpreted abnormally or exaggeratedly, unless clearly
specifically defined.
[0044] The terminology used herein is for the purpose of
describing particular example embodiments only and is not
intended to be limiting of the present invention. In the
specification, the terms of a singular form may include
plural forms unless referred to the contrary. It will be
10
further understood that the terms "comprises" and/or
"comprising" when used in this specification, specify the
presence of stated components, but do not preclude the
presence or addition of one or more other components.
[0045] Hereinafter, preferred embodiments of the present
invention will be described in detail with reference to the
accompanying drawings.
[0046] FIG. 1 is a flowchart of a method of preparing a unit
cell according to an embodiment of the present invention.
[0047] According to an embodiment of the present invention,
when an electrode 11 and separator sheets 1211 and 1221 are
stacked to prepare a unit cell 2, a displacement in position
of the electrode 11 may be prevented by applying an adhesive
in advance whenever the electrode 11 is stably placed on the
separator sheets 1211 and 1221, even if an expensive
separator is not used. Also, since there is no need to
perform a laminating process, a laminator may be removed, and
thus, a volume of an apparatus 1 for preparing a unit cell
may be reduced and a preparation process may be simplified.
[0048] For this purpose, the method of preparing a unit cell
according to the embodiment of the present invention includes
the steps of: unwinding a lower separator sheet 1211 from a
lower separator reel 121; applying an adhesive by a first
nozzle 131 to at least a portion of one surface 1212 facing
upward of the unwound lower separator sheet 1211; stably
placing a first electrode 1112 on the one surface 1212 of the
lower separator sheet 1211 to which the adhesive has been
applied; unwinding an upper separator sheet 1221 from an
upper separator reel 122; applying an adhesive by a second
nozzle 132 to at least a portion of one surface 1222 facing
11
upward of the unwound upper separator sheet 1221; and turning
opposite surfaces of the upper separator sheet 1221 upside
down by a first nip roll 161 so that the one surface 1222 of
the upper separator sheet 1221 to which the adhesive has been
applied is directed downward and adheres to an upper surface
of the first electrode 1112 stably placed on the one surface
1212 of the lower separator sheet 1211.
[0049] Also, after the turning of the opposite surfaces of
the upper separator sheet 1221 upside down, the method may
further include the steps of: applying an adhesive by a third
nozzle 133 to at least a portion of the other surface 1223
facing upward of the upper separator sheet 1221; and stably
placing a second electrode 1122 on the other surface 1223 of
the upper separator sheet 1221 to which the adhesive has been
applied.
[0050] Hereinafter, each step illustrated in the flowchart
of FIG. 1 will be described in detail with reference to FIGS.
2 to 6.
[0051] FIG. 2 is a schematic view of the apparatus 1 for
preparing a unit cell according to an embodiment of the
present invention.
[0052] As illustrated in FIG. 2, the apparatus 1 for
preparing a unit cell according to the embodiment of the
present invention may include a lower separator reel 121 from
which a lower separator sheet 1211 is unwound; a first nozzle
131 for applying an adhesive to at least a portion of one
surface 1212 facing upward of the unwound lower separator
sheet 1211; an upper separator reel 122 from which an upper
separator sheet 1221 is unwound; a second nozzle 132 for
applying an adhesive to at least a portion of one surface
12
1222 facing upward of the unwound upper separator sheet 1221;
and a first nip roll 161 for turning opposite surfaces of the
upper separator sheet 1221 upside down so that the one
surface 1222 of the upper separator sheet 1221 to which the
adhesive has been applied is directed downward and adheres to
an upper surface of the first electrode 1112 stably placed on
the one surface 1212 of the lower separator sheet 1211.
[0053] The lower separator reel 121 is a reel on which the
lower separator sheet 1211 is wound, and the lower separator
sheet 1211 is unwound from the lower separator reel 121. In
addition, the upper separator reel 122 is a reel on which the
upper separator sheet 1221 is wound, and the upper separator
sheet 1221 is unwound from the upper separator reel 122. The
first electrode 1112 is stably placed on the one surface 1212
facing upward of the lower separator sheet 1211 unwound from
the lower separator reel 121, and the upper separator sheet
1221 unwound from the upper separator reel 122 is stacked on
the upper surface of the first electrode 1112. As a result,
a first stack 21 is formed in which the lower separator sheet
1211, the first electrode 1112, and the upper separator sheet
1221 are sequentially stacked. The first stack 21 may be
formed by stacking a plurality of first electrodes 1112 on
the separator sheets 1211 and 1221 while being spaced apart
from each other in a row in a longitudinal direction of the
separator sheets 1211 and 1221 and disposed.
[0054] Transfer directions of the lower separator sheet 1211
and the upper separator sheet 1221 may be different from each
other. For example, as illustrated in FIG. 2, the lower
separator sheet 1211 may be unwound and transferred from one
side of the apparatus 1 for preparing a unit cell to the
13
other side thereof, and the upper separator sheet 1221 may be
unwound and transferred from upper side to lower side. Later,
when the adhesive is applied to the one surface 1222 of the
upper separator sheet 1221, the transfer direction of the
upper separator sheet 1221 may be changed to be the same as
the transfer direction of the lower separator sheet 1211
while the opposite surfaces of the upper separator sheet 1221
are turned upside down. However, the present invention is
not limited thereto, and the transfer directions of the lower
separator sheet 1211 and the upper separator sheet 1221 may
be the same from the beginning. In this case, even if the
opposite surfaces of the upper separator sheet 1221 are later
turned upside down, the transfer direction of the upper
separator sheet 1221 may not be changed.
[0055] The nozzle 13 applies an adhesive to the separator
sheets 1211 and 1221. It is desirable that the adhesive is
uniformly applied to surfaces 1212, 1222, and 1223 facing
upward of the separator sheets 1211 and 1221. Furthermore,
in a case in which viscosity of the adhesive is relatively
high, the adhesive may be applied to entire surfaces of the
surfaces 1212, 1222, and 1223 of the separator sheets 1211
and 1221. However, in a case in which the viscosity of the
adhesive is relatively low, if the adhesive is applied to the
entire surfaces of the surfaces 1212, 1222, and 1223 of the
separator sheets 1211 and 1221, an amount of the adhesive
applied may be excessively large. Accordingly, the adhesive
may flow to the outside of the separator sheets 1211 and 1221
to contaminate other parts, and a function of generating
power may not be smooth when a secondary battery is prepared.
Thus, the adhesive may be applied to upper surfaces of
14
regions of the separator sheets 1211 and 1221 by a spot
application method of applying the adhesive in the form of a
dot or a line application method of applying the adhesive in
the form of a line.
[0056] In contrast, if the amount of the adhesive applied is
excessively small, the electrode 11 is still not fixed to the
separator sheets 1211 and 1221 while the cell is moved, and
the electrode 11 may be out of position. Thus, it is
desirable that a spacing between regions to which the
adhesive is applied is not excessively large.
[0057] The adhesive must maintain adhesiveness even if a
separator is impregnated with an electrolyte solution. Thus,
it is desirable that the adhesive has a property of corrosion
resistance that is not modified by chemical causes. Such an
adhesive is a hot melt adhesive, wherein the adhesive may
include a modified olefin-based thermoplastic resin.
[0058] The nozzle 13 includes the first nozzle 131 for
applying an adhesive to at least a portion of the one surface
1212 facing upward of the unwound lower separator sheet 1211;
the second nozzle 132 for applying an adhesive to at least a
portion of the one surface 1222 facing upward of the unwound
upper separator sheet 1221; and the third nozzle 133 for
applying an adhesive to at least a portion of the other
surface 1223 facing upward of the upper separator sheet 1221.
Specifically, the first nozzle 131 is disposed above the
lower separator sheet 1211 and applies the adhesive to at
least a portion of the one surface 1212 facing upward. In
addition, the second nozzle 132 is disposed above the upper
separator sheet 1221 and applies the adhesive to at least a
portion of the one surface 1222 facing upward. When the
15
opposite surfaces of the upper separator sheet 1221 are later
turned upside down so that the other surface 1223 of the
upper separator sheet 1221 faces upward, the third nozzle 133
is disposed above the upper separator sheet 1221 to apply the
adhesive to at least a portion of the other surface 1223
facing upward.
[0059] The first electrode 1112 and the second electrode
1122 may be prepared by coating a slurry of an electrode
active material, a conductive agent, and a binder on an
electrode collector, drying, and then pressing the coated
electrode collector. According to an embodiment of the
present invention, the first electrode 1112 and the second
electrode 1122 may be prepared in a separate process of
preparing the electrode 11. The first electrode 1112 may be
supplied to a first electrode table 31 or first electrode
magazine (not shown) provided on one side of the apparatus 1
for preparing a unit cell, and the second electrode 1122 may
also be supplied to a second electrode table 32 or second
electrode magazine (not shown) provided on one side of the
apparatus 1 for preparing a unit cell. When the first nozzle
131 applies the adhesive to the one surface 1212 of the lower
separator sheet 1211, a first header 141 may adsorb the first
electrode 1112 and may then transfer the first electrode 1112
to stably place the first electrode 1112 on the one surface
1212 of the lower separator sheet 1211 to which the adhesive
has been applied. Later, when the opposite surfaces of the
upper separator sheet 1221 are turned upside down and the
third nozzle 133 applies the adhesive to the other surface
1223 of the upper separator sheet 1221, a second header 142
may adsorb the second electrode 1122 and may then transfer
16
the second electrode 1122 to stably place the second
electrode 1122 on the other surface 1223 of the upper
separator sheet 1221 to which the adhesive has been applied.
Herein, the first electrode 1112 and the second electrode
1122 may be the electrodes 11 having different polarities.
That is, if the first electrode 1112 is a positive electrode,
the second electrode 1122 may be a negative electrode, and,
if the first electrode 1112 is a negative electrode, the
second electrode 1122 may be a positive electrode.
[0060] A guide roll 15 guides the one surface 1222 of the
upper separator sheet 1221 to face upward when the upper
separator sheet 1221 is unwound and transferred. As
described above, the transfer directions of the upper
separator sheet 1221 and the lower separator sheet 1211 may
be different from each other, and, particularly, the upper
separator sheet 1221 may be unwound and transferred from the
upper side to the lower side. Then, the one surface 1222 of
the upper separator sheet 1221 does not face upward, or even
if the one surface 1222 of the upper separator sheet 1221
faces upward, it may be inclined with a slope. Thus, in
order for the second nozzle 132 to easily apply the adhesive
to the one surface 1222 of the upper separator sheet 1221,
the guide roll 15 may change the transfer direction so that
the one surface 1222 of the upper separator sheet 1221 is
horizontal and faces upward.
[0061] The first nip roll 161 turns the opposite surfaces of
the upper separator sheet 1221 upside down so that the one
surface 1222 of the upper separator sheet 1221 to which the
adhesive has been applied is directed downward and adheres to
the upper surface of the first electrode 1112 stably placed
17
on the one surface 1212 of the lower separator sheet 1211.
When the one surface 1222 of the upper separator sheet 1221
is horizontal and directed upward by the guide roll 15, the
second nozzle 132 applies the adhesive to the one surface
1222 of the upper separator sheet 1221. Then, the one
surface 1222 of the upper separator sheet 1221 must adhere to
the upper surface of the first electrode 1112 located below.
For this purpose, the one surface 1222 of the upper separator
sheet 1221 facing upward must be turned upside down so as to
face downward. Thus, the first nip roll 161 rotates in
contact with the other surface 1223 of the upper separator
sheet 1221, and guides the other surface 1223 of the upper
separator sheet 1221 to face upward. Accordingly, the
opposite surfaces of the upper separator sheet 1221 are
turned upside down, and the one surface 1222 of the upper
separator sheet 1221 may adhere to the upper surface of the
first electrode 1112.
[0062] When the guide roll 15 guides the one surface 1222 of
the upper separator sheet 1221 to face upward, as illustrated
in FIG. 2, the transfer direction of the upper separator
sheet 1221 may be opposite to that of the lower separator
sheet 1211. Then, the first nip roll 161 may reverse the
transfer direction of the upper separator sheet 1221 while
turning the opposite surfaces of the upper separator sheet
1221 upside down. Accordingly, the transfer direction of the
upper separator sheet 1221 may be the same as that of the
lower separator sheet 1211. However, the present invention
is not limited thereto, and, if the transfer directions of
the lower separator sheet 1211 and the upper separator sheet
1221 are the same from the beginning, the first nip roll 161
18
may turn only the opposite surfaces of the upper separator
sheet 1221 upside down without changing the transfer
direction of the upper separator sheet 1221.
[0063] A plurality of first nip rolls 161 may be formed and
disposed on opposite surfaces of the first stack 21, in which
the lower separator sheet 1211, the first electrode 1112, and
the upper separator sheet 1221 are sequentially stacked,
respectively. In addition, the first nip roll 161 may apply
pressure to the first stack 21 while rotating. Accordingly,
the inside of the first stack 21 may be adhered more strongly.
[0064] When the opposite surfaces of the upper separator
sheet 1221 are turned upside down, the other surface 1223 of
the upper separator sheet 1221 faces upward. Then, the third
nozzle 133 applies an adhesive to at least a portion of the
other surface 1223 facing upward. The second header 142 may
adsorb the second electrode 1122 and may then transfer the
second electrode 1122 to stably place the second electrode
1122 on the other surface 1223 of the upper separator sheet
1221 to which the adhesive has been applied. As a result, a
second stack 22 may be formed in which the lower separator
sheet 1211, the first electrode 1112, the upper separator
sheet 1221, and the second electrode 1122 are sequentially
stacked. The second stack 22 may be formed by stacking a
plurality of second electrodes 1122 on the separator sheets
1211 and 1221 while being spaced apart from each other in a
row in the longitudinal direction of the separator sheets
1211 and 1221 and disposed. Since the first electrode 1112
and the second electrode 1122 have different sizes, spacings
may be different. However, it is desirable that the first
electrode 1112 and the second electrode 1122 are all aligned
19
and disposed so that centers thereof coincide.
[0065] A plurality of second nip rolls 162 may be formed and
disposed on opposite surfaces of the second stack 22,
respectively. In addition, the second nip roll 162 may apply
pressure to the second stack 22 while rotating. Accordingly,
the inside of the second stack 22 may be adhered more
strongly.
[0066] The method of preparing a unit cell according to the
embodiment of the present invention may be performed as
follows, using the apparatus 1 for preparing a unit cell as
described above.
[0067] As illustrated in FIG. 2, the lower separator sheet
1211 is first unwound from the lower separator reel 121 and
is transferred from one side of the apparatus 1 for preparing
a unit cell to the other side thereof. Then, the first
nozzle 131 is disposed above the lower separator sheet 1211
to apply an adhesive to at least a portion of the one surface
1212 facing upward of the lower separator sheet 1211 (S101).
The first electrode 1112 prepared in a separate process of
preparing the electrode 11 is supplied to the first electrode
table 31 or first electrode magazine (not shown) provided on
one side of the apparatus 1 for preparing a unit cell. In
addition, the first header 141 may adsorb the first electrode
1112 and may then transfer the first electrode 1112 to stably
place the first electrode 1112 on the one surface 1212 of the
lower separator sheet 1211 to which the adhesive has been
applied (S102).
[0068] The upper separator sheet 1221 is unwound from the
upper separator reel 122 and may be transferred from upper
side to lower side. Then, the guide roll 15 guides the one
20
surface 1222 of the upper separator sheet 1221 to face upward.
Particularly, the guide roll 15 may change the transfer
direction of the upper separator sheet 1221 so that the
transfer direction of the upper separator sheet 1221 is
opposite to that of the lower separator sheet 1211. Then,
the second nozzle 132 is disposed above the upper separator
sheet 1221 to apply an adhesive to at least a portion of the
one surface 1222 facing upward of the upper separator sheet
1221 (S103).
[0069] The first nip roll 161 turns the opposite surfaces of
the upper separator sheet 1221 upside down so that the one
surface 1222 of the upper separator sheet 1221 to which the
adhesive has been applied faces downward (S104). As a result,
the one surface 1222 of the upper separator sheet 1221
adheres to the upper surface of the first electrode 1112
stably placed below the upper separator sheet 1221. In this
case, the first nip roll 161 reverses the transfer direction
of the upper separator sheet 1221 again so that the transfer
direction of the upper separator sheet 1221 may be the same
as that of the lower separator sheet 1211. At the same time,
the first nip rolls 161 are disposed on opposite surfaces of
the first stack 21, in which the lower separator sheet 1211,
the first electrode 1112, and the upper separator sheet 1221
are sequentially stacked, respectively, and may apply
pressure to the first stack 21 while rotating.
[0070] The third nozzle 133 is disposed above the upper
separator sheet 1221 with opposite surfaces turned upside
down, and applies an adhesive to at least a portion of the
other surface 1223 facing upward of the upper separator sheet
1221 (S105). The second electrode 1122 prepared in a
21
separate process of preparing the electrode 11 is supplied to
the second electrode table 32 or second electrode magazine
(not shown) provided on one side of the apparatus 1 for
preparing a unit cell. In addition, the second header 142
may adsorb the second electrode 1122 and may then transfer
the second electrode 1122 to stably place the second
electrode 1122 on the other surface 1223 of the upper
separator sheet 1221 to which the adhesive has been applied
(S106).
[0071] The second nip rolls 162 are disposed on opposite
surfaces of the second stack 22, in which the lower separator
sheet 1211, the first electrode 1112, the upper separator
sheet 1221, and the second electrode 1122 are sequentially
stacked, respectively, and may apply pressure to the second
stack 22 while rotating. In addition, a unit cell 2 may be
prepared by cutting the second stack 22 at a predetermined
interval by a cutter 17.
[0072] FIG. 3 is a schematic side view illustrating in
detail the apparatus 1 for preparing a unit cell according to
the embodiment of the present invention, and FIG. 4 is a
schematic plan view illustrating in detail the apparatus 1
for preparing a unit cell according to the embodiment of the
present invention.
[0073] As illustrated in FIGS. 3 and 4, the apparatus 1 for
preparing a unit cell according to the embodiment of the
present invention further includes a first vision sensor 181
disposed above the first electrode 1112 to photograph the
first electrode 1112 before the first electrode 1112 adheres
to the upper separator sheet 1221; a second vision sensor 182
disposed above the second electrode 1122 to photograph the
22
second electrode 1122 before the second electrode 1122 is
stably placed on the other surface 1223 of the upper
separator sheet 1221; and a third vision sensor 183 disposed
on a side of the first electrode 1112 to photograph the first
electrode 1112 when the first electrode 1112 adheres to the
upper separator sheet 1221.
[0074] The first, second, and third vision sensors 181, 182,
and 183 acquire an image by photographing a specific region
and receiving an image signal for the specific region. For
this purpose, a vision sensor generally includes an imaging
device such as a charge coupled device (CCD) or a
complementary metal-oxide semiconductor (CMOS). Particularly,
the first, second, and third vision sensors 181, 182, and 183
according to an embodiment of the present invention may
acquire images by photographing the first electrode 1112
before adhering to the upper separator sheet 1221, the second
electrode 1122, and the first electrode 1112 after adhering
to the upper separator sheet 1221, respectively.
[0075] Although not shown in the drawings, the apparatus 1
for preparing a unit cell may further include a controller
(not shown) which may determine whether the first electrode
1112 and the second electrode 1122 are defective or not
through the images of the first electrode 1112 and the second
electrode 1122. The controller may determine whether sizes,
shapes, and positions of the first electrode 1112 and the
second electrode 1122 are defective or damaged or not by
comparing the obtained images with previously stored images
of the first electrode 1112 and the second electrode 1122 of
a good product.
[0076] The first vision sensor 181 is disposed above the
23
first electrode 1112 to photograph the first electrode 1112
before the first electrode 1112 adheres to the upper
separator sheet 1221. The first vision sensor 181 may be
disposed above the first electrode table 31 to photograph the
first electrode 1112 waiting on the first electrode table 31
before the first electrode 1112 is adsorbed on the first
header 141. Accordingly, it is possible to easily determine
whether or not the first electrode 1112 is defective, and, if
the first electrode 1112 is defective, it may be removed
before being stably placed on the lower separator sheet 1211.
However, the present invention is not limited thereto, and
the first vision sensor 181 may also be disposed above the
lower separator sheet 1211 to photograph the first electrode
1112 stably placed on the lower separator sheet 1211.
[0077] The second vision sensor 182 is disposed above the
second electrode 1122 to photograph the second electrode 1122
before the second electrode 1122 is stably placed on the
other surface 1223 of the upper separator sheet 1221. The
second vision sensor 182 may be disposed above the second
electrode table 32 to photograph the second electrode 1122
waiting on the second electrode table 32 before the second
electrode 1122 is adsorbed on the second header 142.
Accordingly, it is possible to easily determine whether or
not the second electrode 1122 is defective, and, if the
second electrode 1122 is defective, it may be removed before
being stably placed on the upper separator sheet 1221.
However, the present invention is not limited thereto, and
the second vision sensor 182 may also be disposed above the
upper separator sheet 1221 to photograph the second electrode
1122 stably placed on the upper separator sheet 1221.
24
[0078] The third vision sensor 183 is disposed on the side
of the first electrode 1112 to photograph the first electrode
1112 when the first electrode 1112 adheres to the upper
separator sheet 1221. The third vision sensor 183 may
photograph the first electrode 1112 after the second
electrode 1122 is stably placed on the upper separator sheet
1221. Accordingly, it is possible to easily determine
whether or not the first electrode 1112 is defective even if
the first electrode 1112 is damaged or the first electrode
1112 is out of position in a process of stably placing the
second electrode 1122 on the upper separator sheet 1221.
[0079] When the first electrode 1112 adheres to the upper
separator sheet 1221, opposite surfaces of the first
electrode 1112 adhere to the upper separator sheet 1221 and
the lower separator sheet 1211 to be covered therewith. Then,
even if the third vision sensor 183 photographs the first
electrode 1112, a clear image may not be obtained. Thus, as
illustrated in FIGS. 3 and 4, a separate light source 19 may
be disposed above the upper separator sheet 1221. When the
first electrode 1112 adheres to the upper separator sheet
1221, the light source 19 may radiate light toward the upper
separator sheet 1221, particularly a region photographed by
the third vision sensor 183. As a result, the third vision
sensor 183 may obtain a clearer image.
[0080] If the apparatus 1 for preparing a unit cell
according to the embodiment of the present invention is used,
when the electrode 11 and the separator sheets 1211 and 1221
are stacked to prepare the unit cell 2, a displacement in
position of the electrode 11 may be prevented by applying the
adhesive in advance whenever the electrode 11 is stably
25
placed on the separator sheets 1211 and 1221, even if an
expensive separator is not used. Also, since there is no
need to perform a laminating process, a laminator may be
removed, and thus, a volume of the apparatus 1 for preparing
a unit cell may be reduced and a preparation process may be
simplified.
[0081] FIG. 5 is a schematic view of an apparatus 1a for
preparing a unit cell according to another embodiment of the
present invention.
[0082] According to an embodiment of the present invention,
the first electrode 1112 and the second electrode 1122 are
prepared in a separate process of preparing the electrode 11
and then supplied. However, the apparatus 1a for preparing a
unit cell according to the another embodiment of the present
invention further includes a first electrode reel 111 from
which a first electrode sheet 1111, which is to be the first
electrode 1112, is unwound and a second electrode reel 112
from which a second electrode sheet 1121, which is to be the
second electrode 1122, is unwound. That is, the first
electrode 1112 and the second electrode 1122 may be prepared
immediately by cutting the first electrode sheet 1111 and the
second electrode sheet 1121 in the apparatus 1a for preparing
a unit cell.
[0083] The first electrode reel 111 is a reel on which the
first electrode sheet 1111 is wound, and the first electrode
sheet 1111 is unwound from the first electrode reel 111. In
addition, the second electrode reel 112 is a reel on which
the second electrode sheet 1121 is wound, and the second
electrode sheet 1121 is unwound from the second electrode
reel 112. The first electrode sheet 1111 is cut to form a
26
plurality of first electrodes 1112, and the second electrode
sheet 1121 is cut to form a plurality of second electrodes
1122.
[0084] FIG. 6 is a schematic side view illustrating in
detail the apparatus 1a for preparing a unit cell according
to the another embodiment of the present invention.
[0085] According to another embodiment of the present
invention, as illustrated in FIG. 6, the first vision sensor
181 is disposed above the first electrode 1112 to photograph
the first electrode 1112 before the first electrode 1112
adheres to the upper separator sheet 1221. When a first
cutter 171 cuts the first electrode sheet 1111 to form the
first electrode 1112, the first vision sensor 181 may
photograph the first electrode 1112 before the first
electrode 1112 is stably placed on the one surface 1212 of
the lower separator sheet 1211. When a second cutter 172
cuts the second electrode sheet 1121 to form the second
electrode 1122, the second vision sensor 182 may photograph
the second electrode 1122 before the second electrode 1122 is
stably placed on the other surface 1223 of the upper
separator sheet 1221. When the first electrode 1112 adheres
to the upper separator sheet 1221, the third vision sensor
183 is disposed on a side of the first electrode 1112 to
photograph the first electrode 1112. Thus, it is possible to
determine whether sizes, shapes, and positions of the first
electrode 1112 and the second electrode 1122 are defective or
damaged or not.
[0086] A method of preparing a unit cell according to
another embodiment of the present invention may be performed
as follows, using the apparatus 1a for preparing a unit cell
27
as described above.
[0087] When the first nozzle 131 applies an adhesive to at
least a portion of the one surface 1212 facing upward of the
lower separator sheet 1211 (S101), the first cutter 171 cuts
the first electrode sheet 1111 unwound from the first
electrode reel 111 to form the first electrode 1112. The
first electrode 1112 may be immediately stably placed on the
one surface 1212 of the lower separator sheet 1211 (S102).
When the second nozzle 132 applies an adhesive to at least a
portion of the one surface 1222 facing upward of the upper
separator sheet 1221 (S103), the first nip roll 161 turns
opposite surfaces of the upper separator sheet 1221 upside
down (S104). Thereafter, when the third nozzle 133 applies
an adhesive to at least a portion of the other surface 1223
facing upward of the upper separator sheet 1221 with opposite
surfaces turned upside down (S105), the second cutter 172
cuts the second electrode sheet 1121 unwound from the second
electrode reel 112 to form the second electrode 1122. The
second electrode 1122 may be immediately stably placed on the
other surface 1223 of the upper separator sheet 1221 (S106).
The unit cell 2 may be prepared by cutting the thus-formed
second stack 22 at a predetermined interval with the third
cutter 173.
[0088] It will be understood by those of ordinary skill in
the art that various changes in form and details may be made
therein without departing from the spirit and scope of the
invention as defined by the following claims. Accordingly,
it is to be understood that the invention has been described
by way of illustration and not limitation. Thus, the scope
of the invention is defined by the following claims rather
28
than the foregoing detailed description, and it is to be
interpreted that all changes or modifications derived from
the meaning, scope and equivalent concept of the appended
claims are within the scope of the present invention.
[0089] [Description of the Symbols]
[0090] 1: Unit Cell Preparation Apparatus 2: Unit Cell
[0091] 11: Electrode 13: Nozzle
[0092] 15: Guide Roll 17: Cutter
[0093] 19: Light Source 21: First Stack
[0094] 22: Second Stack 31: First Electrode Table
[0095] 32: Second Electrode Table 111: First Electrode Reel
[0096] 112: Second Electrode Reel 121: Lower Separator Reel
[0097] 122: Upper Separator Reel 131: First Nozzle
[0098] 132: Second Nozzle 133: Third Nozzle
[0099] 141: First Header 142: Second Header
[00100] 161: First Nip Roll 162: Second Nip Roll
[00101] 171: First Cutter 172: Second Cutter
[00102] 173: Third Cutter 181: First Vision Sensor
[00103] 182: Second Vision Sensor 183: Third Vision Sensor
[00104] 1111: First Electrode Sheet 1112: First Electrode
[00105] 1121: Second Electrode Sheet 1122: Second Electrode
[00106] 1211: Lower Separator Sheet 1212: One Surface of the
Lower Separator Sheet
[00107] 1221: Upper Separator Sheet 1222: One Surface of the
Upper Separator Sheet
[00108] 1223: The Other Surface of the Upper Separator Sheet

CLAIMS
1. An apparatus for preparing a unit cell, the
apparatus comprising:
a lower separator reel from which a lower separator
sheet is unwound;
a first nozzle for applying an adhesive to at least a
portion of one surface facing upward of the unwound lower
separator sheet;
an upper separator reel from which an upper separator
sheet is unwound;
a second nozzle for applying an adhesive to at least a
portion of one surface facing upward of the unwound upper
separator sheet; and
a first nip roll for turning opposite surfaces of the
upper separator sheet upside down so that the one surface of
the upper separator sheet to which the adhesive has been
applied is directed downward and adheres to an upper surface
of a first electrode stably placed on the one surface of the
lower separator sheet.
2. The apparatus for preparing a unit cell of claim
1, further comprising a first header which stably places the
first electrode on the one surface of the lower separator
sheet to which the adhesive has been applied.
3. The apparatus for preparing a unit cell of claim
1, further comprising a first electrode reel from which a
first electrode sheet, which is to be the first electrode, is
unwound.
30
4. The apparatus for preparing a unit cell of claim
1, further comprising a first vision sensor disposed above
the first electrode to photograph the first electrode, before
the first electrode adheres to the upper separator sheet.
5. The apparatus for preparing a unit cell of claim
1, wherein the first nip rolls are respectively disposed on
opposite surfaces of a first stack, which is formed by
sequentially stacking the lower separator sheet, the first
electrode, and the upper separator sheet, to apply pressure
to the first stack while rotating.
6. The apparatus for preparing a unit cell of claim
1, further comprising a third nozzle which applies an
adhesive to at least a portion of the other surface facing
upward of the upper separator sheet.
7. The apparatus for preparing a unit cell of claim
6, further comprising second nip rolls respectively disposed
on opposite surfaces of a second stack, which is formed by
sequentially stacking the lower separator sheet, the first
electrode, the upper separator sheet, and a second electrode,
to apply pressure to the second stack while rotating, when
the second electrode is stably placed on the other surface of
the upper separator sheet to which the adhesive has been
applied.
8. The apparatus for preparing a unit cell of claim
7, further comprising a second header which stably places the
31
second electrode on the other surface of the upper separator
sheet to which the adhesive has been applied.
9. The apparatus for preparing a unit cell of claim
7, further comprising a second electrode reel from which a
second electrode sheet, which is to be the second electrode,
is unwound.
10. The apparatus for preparing a unit cell of claim
7, further comprising a second vision sensor disposed above
the second electrode to photograph the second electrode,
before the second electrode is stably placed on the other
surface of the upper separator sheet.
11. The apparatus for preparing a unit cell of claim
7, further comprising a cutter for cutting the second stack
at a predetermined interval.
12. The apparatus for preparing a unit cell of claim
1, further comprising a third vision sensor disposed on a
side of the first electrode to photograph the first electrode,
when the first electrode adheres to the upper separator sheet.
13. The apparatus for preparing a unit cell of claim
12, further comprising a light source disposed above the
upper separator sheet to radiate light toward the upper
separator sheet, when the first electrode adheres to the
upper separator sheet.
14. A method of preparing a unit cell, the method
32
comprising:
unwinding a lower separator sheet from a lower
separator reel;
applying an adhesive by a first nozzle to at least a
portion of one surface facing upward of the unwound lower
separator sheet;
stably placing a first electrode on the one surface of
the lower separator sheet to which the adhesive has been
applied;
unwinding an upper separator sheet from an upper
separator reel;
applying an adhesive by a second nozzle to at least a
portion of one surface facing upward of the unwound upper
separator sheet; and
turning opposite surfaces of the upper separator sheet
upside down by a first nip roll so that the one surface of
the upper separator sheet to which the adhesive has been
applied is directed downward and adheres to an upper surface
of the first electrode stably placed on the one surface of
the lower separator sheet.
15. The method of claim 14, wherein, in the turning
of the opposite surfaces of the upper separator sheet upside
down, the first nip rolls are respectively disposed on
opposite surfaces of a first stack, which is formed by
sequentially stacking the lower separator sheet, the first
electrode, and the upper separator sheet, to apply pressure
to the first stack while rotating.
16. The method of claim 14, further comprising
33
applying an adhesive by a third nozzle to at least a portion
of the other surface facing upward of the upper separator
sheet, after the turning of the opposite surfaces of the
upper separator sheet upside down.
17. The method of claim 16, further comprising stably
placing a second electrode on the other surface of the upper
separator sheet to which the adhesive has been applied, after
the applying of the adhesive by the third nozzle.
18. The method of claim 17, further comprising
respectively disposing second nip rolls on opposite surfaces
of a second stack, which is formed by sequentially stacking
the lower separator sheet, the first electrode, the upper
separator sheet, and the second electrode, to apply pressure
to the second stack while rotating, after the stably placing
of the second electrode.
19. The method of claim 18, further comprising
cutting the second stack at a predetermined interval by a
cutter, after the applying of the pressure to the second
stack.