CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of the
priority of Korean Patent Application No. 10-2016-0084360,
filed on July 04, 2016, which is hereby incorporated by
􀁜􀁇 reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to an electrode, a
method for manufacturing the electrode, and a roller for
manufacturing the electrode, and more particularly, to an
􀁘􀁗􀁇 electrode for reducing a difference in ductility between a
non-coating portion and a coating portion of the electrode, a
method for manufacturing the electrode, and a roller for
manufacturing the electrode.􀁇
BACKGROUND ART
􀁘􀁜􀁇 [0003] Batteries (Cells) that generate electrical energy
through physical reaction or chemical reaction of a material
to supply power to the outside are used when it is difficult
to obtain AC power supplied to the building, or DC power is
needed due to the living environments surrounded by various
􀁙􀁗􀁇 electric and electronic devices.
[0004] Among such batteries, a primary battery and a
secondary battery, which are chemical batteries using
chemical reaction, are being generally used. The primary
battery is a consumable battery which is collectively
􀁙􀁜􀁇 referred to as a dry battery. Also, the secondary battery is
2
a rechargeable battery manufactured by using a material in
which a redox process between electric current and the
material is repeated many times. When reduction reaction is
performed on the material by the current, power is charged.
􀁜􀁇 Also, when oxidation reaction is performed on the material,
power is discharged. Such the charging-discharging is
repeatedly performed to generate electricity.
[0005] In a lithium ion battery of the secondary battery, an
active material is applied to each of a positive electrode
􀁘􀁗􀁇 conductive foil and a negative electrode conductive foil at a
predetermined thickness, and a separator is interposed
between the two conductive foils to wind the two conductive
foils and the separator several times in a jelly-roll or
cylindrical shape and thereby to manufacture an electrode
􀁘􀁜􀁇 assembly. Then, the electrode assembly is accommodated in a
cylindrical or prismatic can, a pouch, and the like and
sealed and processed.
[0006] A conventional electrode assembly, a lithium
secondary battery using the same, and a method for
􀁙􀁗􀁇 manufacturing the lithium secondary battery are disclosed in
Korean Patent Publication No. 10-2008-0037867.
[0007] To manufacture the secondary battery according to the
related art, an active material is applied to an electrode
sheet, and then, an active material coating portion is rolled.
􀁙􀁜􀁇 [0008] However, when the electrode sheet is rolled, there is
3
a problem that a phenomenon such as waviness occurs on the
electrode after the rolling due to a difference in ductility
between a coating portion coated with the active material and
a non-coating portion, which is not coated with the active
􀁜􀁇 material.
[0009] Also, the electrode has a problem that wrinkle or
folding occurs due to a difference in tension between the
coating portion and the non-coating portion when running for
coating or rolling.
􀁘􀁗􀁇 [0010] When the electrode is notched, electrode breakage or
notching failure may occur by the abovementioned phenomena.
DISCLOSURE OF THE INVENTION
TECHNICAL PROBLEM
[0011] Therefore, the present invention has been made to
􀁘􀁜􀁇 solve the abovementioned problems, an object of the present
invention is to provide an electrode for reducing a
difference in ductility between a non-coating portion and a
coating portion, a method for manufacturing the electrode,
and a roller for manufacturing the electrode.
􀁙􀁗􀁇 TECHNICAL SOLUTION
An electrode according to an embodiment of the present
invention includes an electrode foil, a coating portion
coated with an electrode active material on one surface of
the electrode foil, and a non-coating portion which is
􀁙􀁜􀁇 disposed adjacent to the coating portion on the one surface
4
of the electrode foil and is not coated with the electrode
active material and on which a pattern is disposed.
[0012] and on which a pattern that is not coated with the
electrode active material is disposed.
􀁜􀁇 [0013] The pattern may have a plurality of concave grooves
repeatedly arranged.
[0014] The pattern may have a dot shape.
[0015] The pattern may have a strip shape.
[0016] A method for manufacturing an electrode according to
􀁘􀁗􀁇 an embodiment of the present invention includes a preparation
step of preparing an electrode on which a coating portion
coated with an active material and a non-coating portion that
is not coated with the active material are formed, a pattern
formation step of forming a pattern on the non-coating
􀁘􀁜􀁇 portion, and a rolling step of rolling the electrode.
[0017] In the pattern formation step, the pattern may be
formed through punching.
[0018] In the pattern formation step, the pattern may be
formed by cutting the non-coating portion by using a knife.
􀁙􀁗􀁇 [0019] In the pattern formation step, the pattern may be
formed by partially cutting the non-coating portion.
[0020] In the pattern formation step, the pattern may be
formed by using a press.
[0021] A method for manufacturing an electrode according to
􀁙􀁜􀁇 another embodiment of the present invention includes a
5
preparation step of preparing an electrode on which a coating
portion coated with an active material and a non-coating
portion that is not coated with the active material are
formed and a rolling step of rolling the electrode so that
􀁜􀁇 the coating portion has a flat surface, and a pattern is
formed on a surface of the non-coating portion.
[0022] In the rolling step, the coating portion and the noncoating
portion may be rolled at the same time.
[0023] A rolling roller according to an embodiment of the
􀁘􀁗􀁇 present invention includes a coating surface rolling part
having a flat surface and rolling a coating portion of an
electrode and a non-coating surface rolling part which is
continuous from the coating surface rolling part and on which
a pressing part is formed on a surface thereof to roll a non􀁘􀁜􀁇
coating portion of the electrode.
[0024] The pressing part may be engraved in or embossed on a
surface of the pressing part.
ADVANTAGEOUS EFFECTS
[0025] According to the present invention, the difference in
􀁙􀁗􀁇 ductility between the non-coating portion and the coating
portion of the electrode may be reduced.
[0026] According to the present invention, the difference in
ductility between the non-coating portion and the coating
portion of the electrode may be reduced to prevent the
􀁙􀁜􀁇 waviness from occurring on the electrode when the electrode
6
is rolled.
[0027] According to the present invention, when the
electrode is rolled, the waviness and the like may be
prevented from occurring to prevent the electrode breakage or
􀁜􀁇 the notching failure from occurring when the electrode is
notched.
[0028] According to the present invention, when the
electrode having the thin thickness is manufactured, the
defects may be reduced.
􀁘􀁗􀁇 BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a plan view illustrating a portion of an
electrode foil according to an embodiment of the present
invention.
[0030] FIG. 2 is a plan view illustrating a process of
􀁘􀁜􀁇 forming a coating portion and a non-coating portion of FIG. 1
according to an embodiment of the present invention.
[0031] FIG. 3 is a flowchart illustrating a method for
manufacturing an electrode according to an embodiment of the
present invention.
􀁙􀁗􀁇 [0032] FIG. 4 is a plan view illustrating a state in which
the coating portion is formed on the electrode foil of FIG. 1,
and a pattern is not formed on the non-coating portion.
[0033] FIG. 5 is a plan view illustrating a state in which a
portion of the non-coating portion of the electrode is cut
􀁙􀁜􀁇 according to an embodiment of the present invention.
7
[0034] FIG. 6 is a flowchart illustrating a method for
manufacturing an electrode according to another embodiment of
the present invention.
[0035] FIG. 7 is a schematic front view of a roller for
􀁜􀁇 rolling the electrode according to another embodiment of the
present invention.
MODE FOR CARRYING OUT THE INVENTION
[0036] Hereinafter, an electrode, a method for manufacturing
the electrode, and a roller for manufacturing the electrode
􀁘􀁗􀁇 will be described in detail with reference to the
accompanying drawings.
[0037] Terms or words used in this specification and claims
should not be restrictively interpreted as ordinary meanings
or dictionary-based meanings, but should be interpreted as
􀁘􀁜􀁇 meanings and concepts conforming to the scope of the present
invention on the basis of the principle that an inventor can
properly define the concept of a term to describe and explain
his or her invention in the best ways. Therefore, the
embodiment described in the present specification and the
􀁙􀁗􀁇 constitutions shown in the drawings are merely the most
preferred embodiment of the present invention and do not
represent all the technical ideas of the present invention,
and thus, it will be understood that various modifications
and equivalents may be made to take the place of the
􀁙􀁜􀁇 embodiment.
8
[0038] In the drawings, the dimension of each of components
or a specific portion constituting the component is
exaggerated, omitted, or schematically illustrated for
convenience in description and clarity. Thus, the dimension
􀁜􀁇 of each element does not entirely reflect an actual size.
Moreover, detailed descriptions related to well-known
functions or configurations will be ruled out in order not to
unnecessarily obscure subject matters of the present
invention.
􀁘􀁗􀁇 [0039] FIG. 1 is a plan view illustrating a portion of an
electrode foil according to an embodiment of the present
invention, and FIG. 2 is a plan view illustrating a process
of forming a coating portion and a non-coating portion of FIG.
1 according to an embodiment of the present invention.
􀁘􀁜􀁇 [0040] Referring to FIGS. 1 and 2, an electrode 1 according
to an embodiment of the present invention includes an
electrode foil 10, a coating portion 20 coated with an
electrode active material on one surface of the electrode
foil 10 and a non-coating portion 30 which is disposed
􀁙􀁗􀁇 adjacent to the coating portion 20 on one surface of the
electrode foil 10 and is not coated with the electrode active
material and on which a pattern 31 is formed.
[0041] The electrode 1 may be one of a positive electrode
coated with a positive electrode active material and a
􀁙􀁜􀁇 negative electrode coated with a negative electrode active
9
material. The positive electrode and the negative electrode
with a separator therebetween may be stacked several times to
manufacture an electrode assembly.
[0042] Also, the electrode assembly may be manufactured by
􀁜􀁇 winding the stack, in which the positive electrode, the
separator, and the negative electrode are stacked in the form
of a jelly-roll.
[0043] The positive electrode may be an aluminum plate and
include a positive electrode coating portion coated with the
􀁘􀁗􀁇 positive electrode active material and a positive electrode
non-coating portion which is not coated with the positive
electrode active material.
[0044] The positive electrode active material may be a
lithium-containing transition metal oxide or a chalcogenide
􀁘􀁜􀁇 compound such as LiCoO2, LiNiO2, LiMnO2, and LiMnO4.
[0045] For example, the positive electrode coating portion
is formed by applying the positive electrode active material
to at least one surface of the aluminum plate, and the
remaining portion of the aluminum plate, which is not coated
􀁙􀁗􀁇 with the positive electrode active material, may be the
positive electrode non-coating portion.
[0046] The negative electrode may be a copper plate and
include a negative electrode coating portion coated with the
negative electrode active material and a negative electrode
􀁙􀁜􀁇 non-coating portion, which is not coated with the negative
10
electrode active material.
[0047] The negative electrode active material may include a
carbon material such as crystalline carbon, amorphous carbon,
carbon composite, carbon fiber, a lithium metal, or a lithium
􀁜􀁇 alloy.
[0048] For example, the negative electrode coating portion
may be formed by applying the negative electrode active
material to at least one surface of the copper plate, and the
remaining portion of the copper plate, which is not coated
􀁘􀁗􀁇 with the negative electrode active material, may be the
negative electrode non-coating portion.
[0049] For example, the separator may be manufactured by
applying a polyvinylidene fluoride-hexafluoropropylene
copolymer (PVDF-HFP co-polymer) to one base material selected
􀁘􀁜􀁇 from the group consisting of, for example, polyethylene (PE),
polystyrene (PS), polypropylene (PP), and a copolymer of
polyethylene (PE) and polypropylene.
[0050] As illustrated in FIG. 2, a pattern 31 is disposed on
the non-coating portion 30 of the electrode according to an
􀁙􀁗􀁇 embodiment of the present invention. The pattern 31 may have
a plurality of concave grooves repeatedly arranged, a dot
shape, or a stripe shape.
[0051] As described above, the pattern 31 of the non-coating
portion 30 may be recessed from the non-coating portion 30 to
􀁙􀁜􀁇 complement a thickness of the non-coating portion 30 having a
11
thickness less than that of the coating portion 20. Thus,
when the electrode is rolled, a difference in pressure
differently acting on the existing coating portion 20 and
non-coating portion 30 may be minimized to minimize a
􀁜􀁇 difference in ductility between the coating portion 20 and
the non-coating portion 30.
[0052] FIG. 3 is a flowchart illustrating a method for
manufacturing the electrode according to an embodiment of the
present invention.
􀁘􀁗􀁇 [0053] As illustrated in FIG. 3, a method for manufacturing
the electrode according to an embodiment of the present
invention includes a preparation step (S1), a pattern
formation step (S2), and a rolling step (S3).
[0054] FIG. 4 is a plan view illustrating a state in which
􀁘􀁜􀁇 the coating portion is formed on the electrode foil of FIG. 1,
and a pattern is not formed on the non-coating portion, and
FIG. 5 is a plan view illustrating a state in which a portion
of the non-coating portion of the electrode is cut according
to an embodiment of the present invention.
􀁙􀁗􀁇 [0055] As illustrated in FIGS. 3 and 4, the preparation step
(S1) is a step of applying a positive electrode active
material or a negative electrode active material to an
electrode foil 10 to prepare an electrode having a coating
portion 20 coated with an active material and a non-coating
􀁙􀁜􀁇 portion 30 which is not coated with the active material.
12
[0056] As illustrated in FIG. 2, the pattern formation step
(S2) is a step of forming a predetermined pattern 31 on the
non-coating portion 30.
[0057] The pattern 31 is formed by being rolled by a press.
􀁜􀁇 [0058] The pattern 31 may be formed by punching the noncoating
portion 30 through punching or partially cutting the
non-coating portion 30.
[0059] Alternatively, as illustrated in FIG. 5, the pattern
31 may be formed by cutting the non-coating portion 30 by
􀁘􀁗􀁇 using a knife. Here, the non-coating portion 30 may be
partially cut.
[0060] The rolling step (S3) is a step of rolling the
coating portion 20 coated with the active material and the
non-coating portion 30, on which the pattern 31 is formed, at
􀁘􀁜􀁇 the same time.
[0061] In the electrode manufactured through the abovedescribed
method for manufacturing the electrode according to
an embodiment of the present invention as described above,
since the non-coating portion 30 has ductility greater than
􀁙􀁗􀁇 that of the coating portion 20 due to the pattern 31, a
difference in ductility factor may be minimized even though
the coating portion 20 and the non-coating portion 30 are
rolled at the same time by using one rolling roller.
[0062] That is, the non-coating portion 30 may be rolled, or
􀁙􀁜􀁇 cut, or partially cut to form the pattern 31 so that the non-
13
coating portion 30 has the ductility greater than that of the
coating portion 20. Thus, when the non-coating portion and
the coating portion 20 are rolled at the same time, the
ductility of the non-coating portion 30 may increase by the
􀁜􀁇 pattern 31 even though a relatively less pressure is applied
to the non-coating portion 30 as compared with that applied
to the coating portion 20 and thereby to minimize a
difference in ductility of the coating portion 20 and the
non-coating portion 30.
􀁘􀁗􀁇 [0063] FIG. 6 is a flowchart illustrating a method for
manufacturing an electrode according to another embodiment of
the present invention, and FIG. 7 is a schematic front view
of a roller for rolling the electrode according to another
embodiment of the present invention.
􀁘􀁜􀁇 [0064] As illustrated in FIG. 6, a method for manufacturing
an electrode according to another embodiment of the present
invention may include a preparation step (S1a) and a rolling
step (S2a).
[0065] The preparation step (S1a) is a step of applying a
􀁙􀁗􀁇 positive electrode active material or a negative electrode
active material to an electrode foil 10 to prepare an
electrode having a coating portion 20 coated with an active
material and a non-coating portion 30 which is not coated
with the active material.
􀁙􀁜􀁇 [0066] The rolling step (S2a) is a step of rolling the
14
coating portion 20 and the non-coating portion at the same
time so that a surface of the coating portion 20 is flat, and
a pattern is formed on a surface of the non-coating portion
30.
􀁜􀁇 [0067] Referring to FIGS. 6 and 7, in the rolling step (S2a),
when the coating portion 20 and the non-coating portion 30
are rolled at the same time, a surface corresponding to the
coating portion 20 may be flat, and a surface corresponding
to the non-coating portion 30 may be compressed by a rolling
􀁘􀁗􀁇 roller 100 on which a pressing part 121 is formed.
[0068] As described above, when the coating portion 20
having a thickness greater by a height of the applied active
material than that of the non-coating portion 30 is rolled
together with the non-coating portion 30 at the same time, a
􀁘􀁜􀁇 surface of the rolling roller 100, which rolls the coating
portion 20, and a surface of the rolling roller 100, which
rolls the non-coating portion 30, may be different from each
other to minimize a difference in ductility acting on the
coating portion 20 and the non-coating portion 30.
􀁙􀁗􀁇 [0069] That is, the surface of the rolling roller 100, which
rolls the coating portion 20 to correspond to the coating
portion 20 may be flat, and the surface of the rolling roller
100, which rolls the non-coating portion 30 to correspond to
the non-coating portion 30 may be provided with the
􀁙􀁜􀁇 protruding pressing part 121 to complement a difference in
15
thickness of the coating portion 20 and the non-coating
portion 30, thereby minimizing a difference in ductility
acting on the coating portion 20 and the non-coating portion
30.
􀁜􀁇 [0070] As illustrated in FIG. 7, the rolling roller 100
according to another embodiment of the present invention
includes a coating surface rolling part 110 having a flat
surface and rolling the coating portion 20 of the electrode
and a non-coating surface rolling part 120 that is continuous
􀁘􀁗􀁇 from the coating surface rolling part 110 and includes a
pressing part 121 on a surface thereof to roll the noncoating
portion 30 of the electrode.
[0071] The coating surface rolling part 110 may be formed to
correspond to the coating portion 20 of the electrode so that
􀁘􀁜􀁇 the coating portion 20 is rolled to be flat.
[0072] The pressing part 121 may be engraved in or embossed
on the surface of the non-coating surface rolling part 120 so
that the non-coating portion 30 is rolled at the same time
when the coating portion 20 is rolled. As a result, a
􀁙􀁗􀁇 predetermined pattern may be formed on the non-coating
portion 30 by the pressing part 121.
[0073] That is, since the coating portion 20 has a surface
coated with the active material and thus has a thickness
greater than that of the non-coating portion 30, when the
􀁙􀁜􀁇 electrode is rolled by using the general roller, the coating
16
portion 20 and the non-coating portion 30 may have ductility
factors different from each other due to a difference in
pressure acting on the coating portion 20 and the non-coating
portion 30.
􀁜􀁇 [0074] Thus, when the pressing part 121 is formed so that
the non-coating surface rolling part 120 rolling the noncoating
portion 30 protrudes by a predetermined thickness
from the coating surface rolling part 110 in the rolling
roller 100 to allow the rolling roller 100 to roll the
􀁘􀁗􀁇 coating portion 20 and the non-coating portion 30 at the same
time, the thickness of the non-coating portion 30, which is
less than that of the coating portion 20, may be complemented
by the pressing part 121 to minimize the difference in
ductility of the coating portion 20 and the non-coating
􀁘􀁜􀁇 portion 30.
[0075] As described above, according to the present
invention, the difference in ductility between the noncoating
portion and the coating portion of the electrode may
be reduced.
􀁙􀁗􀁇 [0076] According to the present invention, the difference in
ductility between the non-coating portion and the coating
portion of the electrode may be reduced to prevent waviness
from occurring on the electrode when the electrode is rolled.
[0077] According to the present invention, when the
􀁙􀁜􀁇 electrode is rolled, the waviness and the like may be
17
prevented from occurring to prevent electrode breakage or
notching failure from occurring when the electrode is notched.
[0078] According to the present invention, when the
electrode having the thin thickness is manufactured, defects
􀁜􀁇 may be reduced.
[0079] Although the electrode, the method for manufacturing
the electrode, and the roller for manufacturing the electrode
have been described with reference to the exemplary drawings,
various changes and modifications may be made thereto by one
􀁘􀁗􀁇 skilled in the art without departing from the scope and
spirit of the invention as set forth in the appended claims.

I/We Claim:
1. An electrode comprising:
an electrode foil (10);
􀁜􀁇 a coating portion (20) coated with an electrode active
material on one surface of the electrode foil (10); and
a non-coating portion (30) which is disposed adjacent
to the coating portion (20) on the one surface of the
electrode foil (10) and is not coated with the electrode
􀁘􀁗􀁇 active material and on which a pattern (31) is disposed.
2. The electrode of claim 1, wherein the pattern (31) has
a plurality of concave grooves repeatedly arranged.
􀁘􀁜􀁇 3. The electrode of claim 1, wherein the pattern (31) has
a dot shape.
4. The electrode of claim 1, wherein the pattern (31) has
a strip shape.
􀁙􀁗􀁇
5. A method for manufacturing an electrode, the method
comprising:
a preparation step (S1) of preparing an electrode on
which a coating portion coated with an active material and a
􀁙􀁜􀁇 non-coating portion that is not coated with the active
19
material are formed;
a pattern formation step (S2) of forming a pattern on
the non-coating portion; and
a rolling step (S3) of rolling the electrode.
􀁜􀁇
6. The method of claim 5, wherein, in the pattern
formation step (S2), the pattern is formed through punching.
7. The method of claim 5, wherein, in the pattern
􀁘􀁗􀁇 formation step (S2), the pattern is formed by cutting the
non-coating portion by using a knife.
8. The method of claim 5, wherein, in the pattern
formation step (S2), the pattern is formed by partially
􀁘􀁜􀁇 cutting the non-coating portion.
9. The method of claim 5, wherein, in the pattern
formation step (S2), the pattern is formed by using a press.
􀁙􀁗􀁇 10. A method for manufacturing an electrode, the method
comprising:
a preparation step (S1a) of preparing an electrode on
which a coating portion coated with an active material and a
non-coating portion that is not coated with the active
􀁙􀁜􀁇 material are formed; and
20
a rolling step (S2a) of rolling the electrode so that
the coating portion has a flat surface, and a pattern is
formed on a surface of the non-coating portion.
􀁜􀁇 11. The method of claim 10, wherein, in the rolling step
(S2a), the coating portion and the non-coating portion are
rolled at the same time.
12. A rolling roller comprising:
􀁘􀁗􀁇 a coating surface rolling part (110) having a flat
surface and rolling a coating portion of an electrode; and
a non-coating surface rolling part (121) which is
continuous from the coating surface rolling part (110) and on
which a pressing part (121) is formed on a surface thereof to
􀁘􀁜􀁇 roll a non-coating portion of the electrode.
13. The rolling roller of claim 12, wherein the pressing
part (121) is engraved in or embossed on a surface of the
pressing part.