【Technical Field】
[1] This application claims the benefit of priority
to Korean Patent Application No. 2020-0134693 filed on
October 16, 2020, the disclosure of which is incorporated
herein by reference in its entirety.
[2] The present invention relates to an electrode
shaping apparatus having a notching pilot pin and an
electrode shaping method using the same. More
particularly, the present invention relates to an
electrode shaping apparatus having a notching pilot pin
configured to reduce a step that may occur during
notching of an electrode and an electrode shaping method
using the same.
【Background Art】
[3] A secondary battery is manufactured by mounting
an electrode assembly in a cylindrical or prismatic case
made of a metal material or a pouch case made of a
laminate sheet including aluminum, injecting an
electrolytic solution into the case, and hermetically
2
sealing the case.
[4] The electrode assembly, which has a structure in
which a positive electrode and a negative electrode are
stacked in the state in which a separator is interposed
therebetween, is classified as a jelly-roll type
electrode assembly, which is configured to have a
structure in which a long sheet type positive electrode
having an active material applied thereto and a long
sheet type negative electrode having an active material
applied thereto are wound in the state in which a
separator is interposed therebetween; a stacked type
electrode assembly which is configured to have a
structure in which a flat positive electrode and a flat
negative electrode are stacked in the state in which a
separator is interposed therebetween; a stacked and
folded type electrode assembly, which is configured to
have a structure in which unit cells are wound in a state
of being disposed on a long sheet type separator; or a
laminated and stacked type electrode assembly, which is
configured to have a structure in which unit cells are
stacked in the state in which a separator is interposed
therebetween.
[5] In the stacked type electrode assembly, the
stacked and folded type electrode assembly, or the
laminated and stacked type electrode assembly, a single-
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sided electrode plate or a double-sided electrode plate
configured such that an electrode active material is
applied to one surface or opposite surfaces of a current
collector is used.
[6] In general, a method of manufacturing the
electrode assembly includes a process of manufacturing
an electrode sheet, a process of pressing the electrode
sheet, a process of slitting the electrode sheet by a
predetermined length so as to be suitable for the
standards of a cell, a vacuum drying process, a process
of notching an electrode tab on the electrode sheet, and
a process of manufacturing an electrode assembly
including the electrode sheet and a separator.
[7] In connection therewith, FIG. 1 is a plan view
showing a portion of a conventional electrode
manufacturing process.
[8] Referring to FIG. 1, an electrode material
coating portion 120 is formed on only a portion of the
electrode sheet 110 excluding opposite side outer
peripheries 111 and a middle part of the electrode sheet
in a transfer direction A, and an electrode material noncoating portion 121 is formed on the remaining portion of
the electrode sheet excluding the electrode material
coating portion 120.
[9] The electrode sheet 110 is divided into two equal
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parts, i.e., two unit electrode sheets 130, along a
slitting line 112 at the middle part of the electrode
sheet 110 in the transfer direction A.
[10] A first side outer periphery 114 of the unit
electrode sheet 130 divided along the slitting line 112
in the transfer direction A is notched in order to form
an electrode tab 113, and a second side outer periphery
115 of the unit electrode sheet is notched in order to
form a portion to be cut for manufacture of a unit
electrode. In FIG. 1, the electrode tab 113 may be
simultaneously notched when the electrode sheet is
divided into two equal parts along the slitting line 112.
[11] In the specification of the present application,
notching includes not only a process of cutting the
electrode tab so as to fit the shape thereof but also
cutting the electrode sheet into two equal parts along
the slitting line. In addition, the electrode sheet and
a sheet include a metal electrode sheet with or without
an electrode material coating portion.
[12] When the electrode is notched, theoretically, the
electrode sheet must be cut so as to be parallel to the
transfer direction of the electrode sheet and the
electrode tab must be cut so as to be perpendicular
thereto, as shown in the upper part of FIG. 2. In the
electrode sheet 110, the electrode material coating
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portion 120 and the electrode material non-coating
portion 121 are different in thickness from each other.
When notching is performed, therefore, the electrode tab
is not correctly cut but is cut (notched) in a retarded
state, i.e., meandering defects occur (see the lower part
of FIG. 2).
[13] When a step is formed at the electrode tab due to
meandering defects, 1) an upper layer and a lower layer
are not accurately aligned with each other in a stacking
process to manufacture the electrode assembly, whereby
efficiency of a battery is reduced, 2) a protruding
portion of the electrode tab damages a separator, whereby
short circuiting may occur, and 3) when each electrode is
rotated during manufacture of the electrode assembly, a
criterion based on which the position of the electrodes
is accurately controlled and the electrodes are stacked
becomes ambiguous.
[14] Patent Document 1 discloses a method of
manufacturing an electrode plate for batteries that
continuously forms a plurality of electrode plates from a
belt type or hoop type electrode plate by punching using
a punching press constituted by an upper press and a
lower press capable of moving upwards and downwards,
wherein the upper press has a punch and a shear blade
mounted in the front thereof in a cutting direction, the
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lower press has a die having a punch hole, into which the
punch is inserted, and a shear blade mounted in the front
thereof in the cutting direction, when punching is
performed in the state in which opposite sides of
electrode plates are adjacent to each other as a common
side in a longitudinal direction of the electrode plate,
on the assumption that one of the opposite sides in a
direction in which the electrode plates are adjacent to
each other is opposite side A and the common side is side
B, a corner formed by side A and side B is chamfered, and
the lower press is configured such that a stepped upper
part having two or more steps having a hole size
increased stepwise in the punching direction is formed in
the lower part of the punch hole.
[15] Patent Document 1 does not disclose the
construction of the notching pilot pin according to the
present invention, and does not suggest a solution to the
problem to be solved by the present invention, since this
document relates to preventing clogging due to cut scraps
of the electrode plate and increasing the lifespan of the
notching punch.
[16] Patent Document 2 discloses a notching apparatus
for notching a continuous electrode sheet having an
electrode active material applied to one surface or
opposite surfaces thereof at unit electrode intervals in
7
order to manufacture a plurality of unit electrodes from
the electrode sheet, the notching apparatus including a
press configured to notch the upper end and the lower end
of the electrode sheet in the state in which the position
of the press is fixed and two or more grippers located at
the rear of the press in a direction in which the
electrode sheet is supplied, the grippers being
configured to hold and transfer the electrode sheet by
one pitch, which is a size corresponding to a unit
electrode, in response to the operation of the press,
wherein, when one of the grippers holds and transfers the
electrode sheet, the other grippers moves to positions
for holding.
[17] Patent Document 2 is characterized in that
notches are formed in the electrode sheet, and the
electrode sheet is supplied by one pitch by the first and
second grippers and is then punched, whereby notching is
performed at predetermined intervals, which, however, is
not a solution to meandering defects.
[18] Patent Document 3 discloses an electrode
manufacturing apparatus including a notching roller, the
electrode manufacturing apparatus including a transfer
unit configured to continuously transfer a first
electrode sheet having an electrode active material
applied to a long sheet type current collector in order
8
to notch and cut the first electrode sheet, a notching
roller having a cylindrical structure, the notching
roller being configured to notch one surface of the first
electrode sheet by rotation in order to manufacture a
second electrode sheet having one side outer periphery
and the other side outer periphery continuously formed,
and a cutter configured to cut the notched second
electrode sheet to a length corresponding to the width of
the electrode in order to manufacture a final electrode,
wherein the notching roller includes a first notching
portion configured to form one side outer periphery of
the second electrode sheet and a second notching portion
configured to form the other side outer periphery of the
second electrode sheet when viewed in plan.
[19] In Patent Document 3, it is described that the
notching roller is used, whereby no notching step occurs.
In the case in which the roller type roller is used,
however, deviation in thickness between an electrode
material coating portion and an electrode material noncoating portion is continuously accumulated, whereby
meandering defects may be increased, and Patent Document
3 does not recognize such a problem.
[20] Patent Document 4 relates to a press apparatus
configured to form a plurality of electrode plates of a
lithium ion polymer battery used in a hybrid electric
9
vehicle at once, wherein an upper press having a cutting
means and a lower press configured to assist the upper
press are installed, a thin flat electrode plate material
is continuously supplied therebetween to simultaneously
form a plurality of electrode plate members provided in a
battery, whereby it is possible to accurately, uniformly,
and continuously manufacture a plurality of electrode
plates at once.
[21] In Patent Document 4, a notching portion is
formed on a middle cutter blade such that punching is
performed while the boundary between the electrode plate
members is marked; however, this document does not
recognize a problem of meandering defects.
[22] In a process of manufacturing electrodes in large
quantities through notching, as described above, a
problem of a step being formed due to meandering defects
has a continuous influence on manufacture of an electrode
assembly, which is a subsequent process, and the
performance of a battery based thereon. However, such a
problem is still not recognized, and a clear solution to
such a problem has not been suggested yet.
[23] Japanese Registered Patent Publication No.
5159007 (2012.12.21) (“Patent Document 1”)
[24] Korean Registered Patent Publication No. 1326628
(2013.11.01) (“Patent Document 2”)
10
[25] Korean Registered Patent Publication No. 2026126
(2019.09.23) (“Patent Document 3”)
[26] Korean Registered Patent Publication No. 1737790
(2017.05.15) (“Patent Document 4”)
【Disclosure】
【Technical Problem】
[27] The present invention has been made in view of
the above problems, and it is an object of the present
invention to provide an electrode shaping apparatus
capable of solving a problem of a step being formed at an
electrode tab that may occur during notching and an
electrode shaping method using the same.
【Technical Solution】
[28] In order to accomplish the above object, the
present invention provides an electrode shaping apparatus
including a sheet transfer unit configured to move an
electrode sheet at a predetermined speed; a fixing unit
configured to fix the electrode sheet; and a punch unit
including a center punching unit configured to remove a
central part of the electrode sheet and a side punching
unit configured to remove a portion of an outer
periphery of the electrode sheet by notching, wherein
the center punching unit includes a hole punching member
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and a notching pilot pin.
[29] The center punching unit may include a
rectangular parallelepiped main body having a major axis
in a movement direction of the electrode sheet; the hole
punching member formed at a rear end of the main body in
the movement direction of the electrode sheet; and the
notching pilot pin formed under a front end of the main
body in the movement direction of the electrode sheet.
[30] The main body may be formed in a rectangular
parallelepiped shape having a major axis in the movement
direction of the electrode sheet, and may include a main
body punching surface configured to punch the electrode
sheet as the lower surface of the rectangular
parallelepiped.
[31] The hole punching member may include an
enlarged portion extending from the rear end of the main
body in the movement direction of the electrode sheet,
the width of the punching surface being increased at the
enlarged portion and configured to punch the electrode
sheet; a reduced portion extending from the enlarged
portion, the width of the punching surface being
decreased at the reduced portion along the major axis
and configured to punch the electrode sheet; and a pin
punching portion extending from the reduced portion, the
pin punching portion configured to punch a catching
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recess, in which the notching pilot pin is configured to
be caught, in the electrode sheet.
[32] The section of the notching pilot pin may be any
one of a circle, an arc, a wedge, a triangle, and a
quadrangle.
[33] The fixing unit may be provided in the middle
thereof with a middle groove corresponding in shape to
the center punching unit.
[34] The middle groove may have a sufficient depth
for the notching pilot pin to be inserted into the
middle groove.
[35] In addition, the present invention provides an
electrode shaping method using the electrode shaping
apparatus, the electrode shaping method including S1)
transferring an electrode sheet by a predetermined
length using the sheet transfer unit; S2) transferring
the electrode sheet or the punch unit such that the
notching pilot pin is caught in a recess formed in the
electrode sheet in a previous step of punching such that
the notching pilot pin is caught in the recess; S3)
pressing the electrode sheet using the punch unit to
punch the electrode sheet; and S4) spacing the punch
unit apart from the electrode sheet.
[36] In step S4), a distance by which the punch unit
is spaced apart from the electrode sheet may be equal to
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or less than a distance by which at least a portion of
the notching pilot pin remains inserted in the recess of
the electrode sheet.
[37] In addition, the present invention provides an
electrode shaped using the electrode shaping apparatus.
【Advantageous Effects】
[38] As is apparent from the above description, an
electrode shaping apparatus having a notching pilot pin
according to the present invention and an electrode
shaping method using the same have an effect in that it
is possible to solve a problem, which may occur during
notching, of a step being formed at an electrode tab,
compared to a conventional electrode shaping apparatus.
[39] The present invention has an effect in that it
is possible to remove meandering defects that may occur
in the conventional electrode shaping apparatus, whereby
1) an upper layer and a lower layer are accurately
aligned with each other in a stacking process to
manufacture the electrode assembly, whereby efficiency of
a battery is increased, 2) there is no protruding portion
of the electrode tab, whereby damage to a separator and
occurrence of a short circuit are prevented, and 3) when
each electrode is rotated during manufacture of the
electrode assembly, a criterion based on which the
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position of the electrodes is accurately controlled and
the electrodes are stacked becomes clear.
【Description of Drawings】
[40] FIG. 1 is a plan view showing a portion of a
conventional electrode manufacturing process.
[41] FIG. 2 is a schematic view showing meandering
defects of notching in the conventional electrode
manufacturing process.
[42] FIG. 3 is a perspective view of an electrode
shaping apparatus according to an embodiment of the
present invention.
[43] FIG. 4 is a perspective view and a sectional
view of a center punching unit according to an
embodiment of the present invention.
[44] FIG. 5 is a schematic view showing a coupling
relationship between a notching pilot pin and a catching
recess according to an embodiment of the present
invention.
【Best Mode】
[45] Now, preferred embodiments of the present
invention will be described in detail with reference to
the accompanying drawings such that the preferred
embodiments of the present invention can be easily
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implemented by a person having ordinary skill in the art
to which the present invention pertains. In describing
the principle of operation of the preferred embodiments
of the present invention in detail, however, a detailed
description of known functions and configurations
incorporated herein will be omitted when the same may
obscure the subject matter of the present invention.
[46] In addition, the same reference numbers will be
used throughout the drawings to refer to parts that
perform similar functions or operations. In the case in
which one part is said to be connected to another part in
the entire specification, not only may the one part be
directly connected to the other part, but also, the one
part may be indirectly connected to the other part via a
further part. In addition, that a certain element is
included does not mean that other elements are excluded,
but means that such elements may be further included
unless mentioned otherwise.

【CLAIMS】
【Claim 1】 An electrode shaping apparatus comprising:
a sheet transfer unit configured to move an
electrode sheet at a predetermined speed;
a fixing unit configured to fix the electrode sheet;
and
a punch unit including:
a center punching unit configured to remove a
central part of the electrode sheet; and
a side punching unit configured to remove a
portion of an outer periphery of the electrode
sheet by notching,
wherein the center punching unit comprises a hole
punching member and a notching pilot pin.
【Claim 2】 The electrode shaping apparatus according
to claim 1, wherein the center punching unit comprises:
a rectangular parallelepiped main body having a
major axis in a movement direction of the electrode
sheet;
the hole punching member formed at a rear end of
the main body in the movement direction of the electrode
sheet; and
the notching pilot pin formed under a front end of
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the main body in the movement direction of the electrode
sheet.
【Claim 3】 The electrode shaping apparatus according
to claim 2, wherein the main body is formed in a
rectangular parallelepiped shape having a major axis in
the movement direction of the electrode sheet, and
includes a main body punching surface configured to
punch the electrode sheet as a lower surface of the
rectangular parallelepiped.
【Claim 4】 The electrode shaping apparatus according
to claim 2, wherein the hole punching member comprises:
an enlarged portion extending from the rear end of
the main body in the movement direction of the electrode
sheet, a width of the punching surface being increased
at the enlarged portion and configured to punch the
electrode sheet;
a reduced portion extending from the enlarged
portion, the width of the punching surface being
decreased at the reduced portion along the major axis
and configured to punch the electrode sheet; and
a pin punching portion extending from the reduced
portion, the pin punching portion configured to punch a
catching recess, in which the notching pilot pin is
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configured to be caught, in the electrode sheet.
【Claim 5】 The electrode shaping apparatus according
to claim 2, wherein a section of the notching pilot pin
is any one of a circle, an arc, a wedge, a triangle, and
a quadrangle.
【Claim 6】 The electrode shaping apparatus according
to claim 1, wherein the fixing unit is provided in a
middle thereof with a middle groove corresponding in
shape to the center punching unit.
【Claim 7】 The electrode shaping apparatus according
to claim 6, wherein the middle groove has a sufficient
depth for the notching pilot pin to be inserted into the
middle groove.
【Claim 8】 An electrode shaping method using the
electrode shaping apparatus according to any one of
claims 1 to 7, the electrode shaping method comprising:
S1) transferring an electrode sheet by a
predetermined length using the sheet transfer unit;
S2) transferring the electrode sheet or the punch
unit such that the notching pilot pin is caught in a
recess formed in the electrode sheet in a previous step
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of punching such that the notching pilot pin is caught
in the recess;
S3) pressing the electrode sheet using the punch
unit to punch the electrode sheet; and
S4) spacing the punch unit apart from the electrode
sheet.
【Claim 9】 The electrode shaping method according to
claim 8, wherein, in step S4), a distance by which the
punch unit is spaced apart from the electrode sheet is
equal to or less than a distance by which at least a
portion of the notching pilot pin remains inserted in
the recess of the electrode sheet.
【Claim 10】 An electrode shaped using the electrode
shaping apparatus according to any one of claims 1 to 7.