Title of Invention: Secondary Battery Electrode and Electrode Manufacturing Method
technical field
[One]
Cross Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0092474 dated July 30, 2019, and all contents disclosed in the documents of the Korean patent application are incorporated as a part of this specification.
[3]
technical field
[4]
The present invention relates to an electrode for a secondary battery and a method for manufacturing the electrode, and more particularly, to an electrode for a secondary battery having an atypical shape and a method for manufacturing the electrode.
background
[5]
Secondary batteries capable of repetitive charging and discharging generally have a regular shape such as a rectangular parallelepiped or a cylinder, but as the shapes of electronic devices become diversified and the need to maximize the utility of the internal space of electronic devices increases, electronic devices The shape of the secondary battery mounted therein is also required to be atypical unlike the prior art.
[6]
In the case of a secondary battery having an atypical shape, it is generally manufactured by manufacturing an electrode assembly having an atypical shape, accommodating it in a packaging material such as a pouch-type packaging material, and sealing the electrode assembly.
[7]
However, when the shape of the electrode constituting the electrode assembly is out of the desired shape, there is a problem in that the electrode is damaged while the electrode assembly is accommodated in the exterior material. In particular, in the process of cutting the electrode using a mold to manufacture an electrode having an atypical shape, when the electrode is defective in a region where the electrode is notched due to undesirable movement of the mold or electrode, the electrode described above damage problems occurred frequently.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[8]
Accordingly, the problem to be solved by the present invention is to solve the problem of electrode damage that occurs in the process of manufacturing a secondary battery having an atypical shape.
means of solving the problem
[9]
According to one aspect of the present invention for achieving the above object, a portion of the electrode sheet is cut along the first cutting line N1 including the closed curve, and the shape corresponding to the closed curve of the first cutting line N1 is A first cutting step to form an electrode having; and the second cutting, which is made after the first cutting step and is separate from the electrode formed in the first cutting step by further cutting a part of the electrode sheet along a second cutting line N2 including a closed curve a second cutting step of forming an electrode having a shape corresponding to the closed curve of the line (N2); Including, wherein the first cutting line (N1) and the second cutting line (N2) cross each other to form an intersecting region (C1) on the electrode sheet, in the intersecting region (C1), the first The cutting line N1 is formed as a straight line SL1, and one end of the straight line SL1 is connected to a curve CL constituting a part of the first cutting line N1, and the straight line SL1 is the A method of manufacturing an electrode connected by a tangent to the curve CL is provided.
[10]
In the crossing region C1 , the second cutting line N2 may be formed as a straight line SL2 crossing the straight line SL1 of the first cutting line N1 .
[11]
In the first cutting step and the second cutting step, the overall shape of the first cutting line N1 and the overall shape of the second cutting line N2 may be the same.
[12]
Each of the electrodes formed in the first cutting step and the second cutting step has a first width (W1) and a first body portion extending in a first direction (D1) by a first length (L1); and a second body portion having a second width (W2) smaller than the first length (L1) and extending from one end of the first body portion by a second length (L2) in a second direction (D2); may include
[13]
The crossing region C1 may be formed at one end adjacent to the electrode formed in the first cutting step among both ends of the second body portion of the electrode formed in the second cutting step in the second length L2 direction. can
[14]
In the electrode formed in the first cutting step and the second cutting step, the first direction D1 and the second direction D2 may be perpendicular to each other.
[15]
In the first cutting step and the second cutting step, a plurality of electrodes may be formed, respectively.
[16]
The electrodes formed in the first cutting step and the second cutting step include an electrode tab having a shape protruding in one direction, and the plurality of electrodes formed in the plurality of electrodes respectively formed in the first cutting step and the second cutting step At least some of the electrode tabs may protrude in opposite directions.
[17]
The electrode formed in the first cutting step and the electrode formed in the second cutting step may be in contact with an area where the first cutting line N1 and the second cutting line N2 overlap as a boundary.
[18]
According to another aspect of the present invention for achieving the above object, the first body portion having a first width (W1) and extending by a first length (L1) in the first direction (D1); and a second body portion having a second width (W2) smaller than the first length (L1) and extending from one end of the first body portion by a second length (L2) in a second direction (D2); Including, at least one of the corners of one end of the second body portion in the second length (L2) direction is formed with a region where two straight lines meet, and one end of any one of the two straight lines is connected to a curved line , The one straight line is provided with an electrode for a secondary battery connected to the curve and a tangent line.
[19]
An angle θ where the two straight lines meet may be an obtuse angle.
Effects of the Invention
[20]
According to the present invention, it is possible to solve the problem of electrode damage that occurs in the process of manufacturing a secondary battery having an atypical shape.
Brief description of the drawing
[21]
1 is a plan view illustrating a first cutting line formed in an electrode sheet by a first cutting step in an electrode manufacturing method according to the present invention.
[22]
2 is a plan view illustrating a second cut line formed in an electrode sheet by a second cutting step in the method for manufacturing an electrode according to the present invention.
[23]
3 is an enlarged plan view of one of the intersection regions of the first cut line and the second cut line in the electrode manufacturing method according to the present invention.
[24]
FIG. 4 is an enlarged plan view illustrating an intersection area of ​​a first cut line and a second cut line in an electrode manufacturing method according to a comparative example.
Modes for carrying out the invention
[25]
Hereinafter, an electrode manufacturing method and an electrode for a secondary battery according to the present invention will be described with reference to the drawings.
[26]
[27]
Electrode manufacturing method
[28]
1 is a plan view illustrating a first cut line formed on an electrode sheet by a first cutting step in an electrode manufacturing method according to the present invention, and FIG. 2 is a second cutting step in the electrode manufacturing method according to the present invention. It is a plan view showing the second cutting line formed on the electrode sheet by the
[29]
1 , the electrode manufacturing method according to the present invention may include a first cutting step of cutting a portion of the electrode sheet 10 to form the electrode 100 . In more detail, in the first cutting step, the electrode sheet 10 may be cut along the first cutting line N1 . In FIG. 1 , the first cutting line N1 is indicated by a dashed dotted line.
[30]
In this case, the first cutting line N1 may include a closed curve, and in the first cutting step, the electrode 100 may have a shape corresponding to the closed curve included in the first cutting line N1 . 1 illustrates a case in which two electrodes 100 are formed symmetrically on the electrode sheet 10 by the first cutting step.
[31]
On the other hand, as shown in FIG. 2, the electrode manufacturing method according to the present invention is made after the first cutting step, and a part of the electrode sheet 10 is further cut to separate from the electrode formed in the first cutting step. A second cutting step of forming an electrode may be further included. In more detail, in the second cutting step, the electrode sheet 10 may be cut along the second cutting line N2 . In FIG. 2 , the first cutting line N1 formed in the first cutting step is illustrated by a dashed-dotted line, and in the second cutting step, the second cutting line N2 is illustrated by a dotted dashed line.
[32]
Like the first cutting line N1 , the second cutting line N2 may also include a closed curve. Even in the second cutting step, the electrode 100 corresponds to the closed curve included in the second cutting line N2 . may have a shape.
[33]
Also, each of the first cutting line N1 and the second cutting line N2 may include a plurality of closed curves. That is, according to the present invention, in the first cutting step and the second cutting step, a plurality of electrodes 100 may be formed, respectively. 1 and 2 show a case in which two electrodes 100 are formed symmetrically to each other on the electrode sheet 10 by the first cutting step and the second cutting step, respectively.
[34]
In this case, the second cutting step may be performed after the first cutting step is performed on the electrode sheet 10 and the electrode sheet 10 moves in one direction. In addition, the mold (not shown) for cutting the electrode sheet 10 in the first cutting step and the mold cutting the electrode sheet 10 in the second cutting step may be the same. Accordingly, in the first cutting step and the second cutting step of the electrode manufacturing method according to the present invention, the overall shape of the first cutting line N1 and the overall shape of the second cutting line N2 may be identical to each other. Accordingly, the shape of the electrode formed in the first cutting step and the shape of the electrode formed in the second cutting step may also be the same.
[35]
On the other hand, the structure of the electrode formed in the first cutting step and the second cutting step is as follows. That is, as shown in FIGS. 1 and 2 , the electrode 100 formed in the first cutting step and the second cutting step is formed from the body 110 and the body 110 forming the body of the electrode, respectively. The electrode tab 120 having a shape protruding in the direction may be included. At this time, the body portion 110 has a first width W1 and is smaller than the first body portion 112 extending in the first direction D1 by a first length L1 and the first length L1. A second body portion 114 having a second width W2 and extending from one end of the first body portion 112 in the second direction D2 by a second length L2 may be included. It may be understood that the body portion 110 has an L-shape as shown in FIGS. 1 and 2 . Accordingly, as shown in FIGS. 1 and 2 , the first direction D1 and the second direction D2 in the body part 110 may be perpendicular to each other.
[36]
Meanwhile, at least some of the plurality of electrode tabs 120 respectively formed on the plurality of electrodes 100 formed in the first cutting step and the second cutting step may protrude in opposite directions. 1 and 2, the electrode tab 120 of the electrode 100 formed on the electrode sheet 10 among the two electrodes 100 formed in the first cutting step and the second cutting step, respectively, protrudes upward, , the electrode tab 120 of the electrode 100 formed under the electrode sheet 10 is shown to protrude downward.
[37]
Meanwhile, according to the present invention, as shown in FIG. 2 , the first cutting line N1 and the second cutting line N2 may overlap each other in some areas. In this case, the electrode formed in the first cutting step and the electrode formed in the second cutting step may be in contact with each other with the boundary between the area where the first cutting line N1 and the second cutting line N2 overlap. In FIG. 2 , a boundary at which the electrode formed by the first cutting line N1 and the electrode formed by the second cutting line N2 are in contact with each other is illustrated by a dashed-dotted line, which is greater than the second cutting line N2. It should be noted that, since the first cutting line N1 is formed first, it is only illustrated with a dashed-dotted line for convenience, and it is actually an area where the first cutting line N1 and the second cutting line N2 overlap.
[38]
Continuing to refer to FIG. 2 , according to the present invention, the first cutting line N1 and the second cutting line N2 respectively formed in the first cutting step and the second cutting step may cross each other. Accordingly, cross regions C1 , C2 , and C3 that are regions where the first cutting line N1 and the second cutting line N2 intersect each other may be formed on the electrode sheet 10 . A plurality of intersection regions may be formed. FIG. 2 shows a case in which a total of six intersection regions are formed. At this time, in the present specification, two crossing regions formed at positions symmetric to each other will be denoted by the same reference numerals, respectively.
[39]
At this time, referring to FIG. 2 , at least some of the crossing regions are the electrodes formed in the first cutting step among both ends in the second length L2 direction of the second body 114 of the electrode formed in the second cutting step. It may be formed at one end (ie, the right end of the second body portion of the electrode formed in the second cutting step) adjacent to the . In the present specification, the cross region formed at one end adjacent to the electrode formed in the first cutting step among both ends in the second length (L2) direction of the second body portion 114 of the electrode formed in the second cutting step is denoted by a reference number. Let's name it C1. Unless otherwise specified below, the term 'intersection area' means an intersection area designated by reference numeral C1.
[40]
3 is an enlarged plan view of one of the intersection regions of the first cut line and the second cut line in the electrode manufacturing method according to the present invention.
[41]
As shown in FIG. 2 , the first cutting line N1 formed in the first cutting step and the second cutting line N2 formed in the second cutting step intersect each other, thereby forming an intersecting region C1 on the electrode sheet. can be formed.
[42]
According to the present invention, in the intersection region C1 , the first cutting line N1 and the second cutting line N2 may cross each other in a straight line. Hereinafter, a straight line formed in the intersection region C1 of the first cutting line N1 is referred to as reference numeral SL1, and a straight line formed in the intersection area C1 of the second cutting line N2 is referred to as reference numeral SL2. to name
[43]
Meanwhile, according to the present invention, as shown in FIG. 3 , one end of the straight line SL1 formed in the intersection region C1 of the first cutting line N1 is curved ( CL), and the straight line SL1 may be connected to the curved line CL by a tangent line. That is, according to the present invention, the slope of the straight line SL1 formed in the intersection region C1 of the first cutting line N1 and the slope of the tangent line of the curve CL at the point where the straight line SL1 intersects are the same. can
[44]
According to the present invention, it is possible to minimize the problem of electrode damage in the process of manufacturing a secondary battery using an electrode, particularly, an electrode having an atypical shape.
[45]
FIG. 4 is an enlarged plan view illustrating an intersection area of ​​a first cut line and a second cut line in an electrode manufacturing method according to a comparative example.
[46]
According to the comparative example, in a region where the first cutting line N1' and the second cutting line N2' intersect each other, the first cutting line N1' is formed in a curved shape having a point of inflection, When the slope of the first cutting line N1' at the inflection point is the same as the slope of the second cutting line N2', the point where the first cutting line N1' and the second cutting line N2' intersect is the second At the inflection point of the first cutting line N1 ′, that is, when the second cutting line N2 ′ is formed along a solid line with reference to FIG. 2 , an electrode having a soft edge may be manufactured.
[47]
However, if the first cutting line N1' and the second cutting line N2' do not intersect at the inflection point due to undesirable movement of the electrode sheet or the mold, an electrode having a quality with angular edges can be manufactured. there is.
[48]
In particular, when the second cutting line N2' is formed below the point where the inflection point is formed in the first cutting line N1', that is, referring to FIG. 2 , the second cutting line N2' is formed along the dotted line. When formed, electrodes with sharp edges can be manufactured. In particular, as shown in FIG. 4 , when the slope of the first cutting line N1 ′ is greatly changed as the distance from the inflection point increases, the first cutting line N1 ′ and the second cutting line N2 ′ intersect. Since the curved region of the indented shape is formed around the edge (the inner region of the circle shown in FIG. 4) formed in the region to be formed, a sharper edge may be formed. In particular, when a sharp corner is formed on the electrode, it is easy to cause a problem in that the electrode is damaged while the electrode assembly including the electrode is accommodated in the casing.
[49]
However, according to the present invention, even if the point at which the first cut line N1 and the second cut line N2 intersect each other changes due to undesirable movement of the electrode sheet or the mold, an electrode having a corner having a certain quality is formed. can be manufactured.
[50]
That is, according to the present invention, the region where the first cutting line N1 and the second cutting line N2 intersect each other is a straight line, and at the same time, a straight line ( Since SL1) is tangentially connected to the curve CL, the sharpness of the edge of the electrode in the intersection region C1 is remarkably improved compared to the comparative example, so that the problem of electrode damage can be solved.
[51]
Meanwhile, according to the present invention, among angles formed by the intersection of the first cutting line N1 and the second cutting line N2 in the intersection region C1, the angle θ formed in the region where the electrode is formed may be an obtuse angle.
[52]
Electrode for secondary battery
[53]
1 to 4 , the electrode 10 for a secondary battery according to the present invention may include a body 110 and an electrode tab 120 protruding from the body in one direction. At this time, the body 110 has a first width W1 and a first body portion 112 extending by a first length L1 in the first direction D1, and a first body portion smaller than the first length L1. The second body portion 114 may include a second body portion 114 having a second width W2 and extending from one end portion of the first body portion by a second length L2 in the second direction D2. It may be understood that the body portion 110 has an L-shape as described above.
[54]
At this time, as shown in FIGS. 1 and 2 , a region where two straight lines meet may be formed in at least one of the corners of one end of the second body part 114 in the second length L2 direction, and the two One end of any one of the straight lines may be connected to a curved line, and the one straight line may be connected to the curved line by a tangent line.
[55]
Also, as shown in FIG. 3 , an angle θ where two straight lines meet may be an obtuse angle.
[56]
Although the present invention has been described with reference to limited examples and drawings, the present invention is not limited thereto, and it is described below with the technical idea of ​​the present invention by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various implementations are possible within the equivalent scope of the claims.
[57]
[Explanation of code]
[58]
10: electrode sheet
[59]
100: electrode
[60]
110: body part
[61]
112: first body part
[62]
114: second body part
[63]
120: electrode tab
[64]
A1, A2: overlapping area
[65]
C1, C2, C3: intersection area
[66]
D1: first direction
[67]
D2: second direction
[68]
L1: first length
[69]
L2: second length
[70]
N1: first cut line
[71]
N2: second cutting line
[72]
W1: first width
[73]
W2: second width
[74]
SL1: straight line of the first cutting line
[75]
SL2: straight line of the second cutting line
[76]
CL: curve of the first cut line
Claims
[Claim 1]
a first cutting step of cutting a portion of the electrode sheet along a first cutting line N1 including a closed curve to form an electrode having a shape corresponding to the closed curve of the first cutting line N1; and the second cutting, which is made after the first cutting step and is separate from the electrode formed in the first cutting step by further cutting a part of the electrode sheet along a second cutting line N2 including a closed curve a second cutting step of forming an electrode having a shape corresponding to the closed curve of the line (N2); Including, wherein the first cutting line (N1) and the second cutting line (N2) cross each other to form an intersecting region (C1) on the electrode sheet, in the intersecting region (C1), the first The cutting line N1 is formed as a straight line SL1, and one end of the straight line SL1 is connected to a curve CL constituting a part of the first cutting line N1, and the straight line SL1 is the A method of manufacturing an electrode connected by a curve (CL) and a tangent line.
[Claim 2]
The method according to claim 1, wherein in the crossing region (C1), the second cutting line (N2) is formed as a straight line (SL2) intersecting the straight line (SL1) of the first cutting line (N1).
[Claim 3]
The method according to claim 1, wherein in the first cutting step and the second cutting step, the overall shape of the first cutting line (N1) and the overall shape of the second cutting line (N2) are the same.
[Claim 4]
The method according to claim 1, wherein the electrode formed in the first cutting step and the second cutting step, each of the first body portion having a first width (W1) and extending in the first direction (D1) by a first length (L1); and a second body portion having a second width (W2) smaller than the first length (L1) and extending from one end of the first body portion by a second length (L2) in a second direction (D2); Electrode manufacturing method comprising a.
[Claim 5]
5 . The method of claim 4 , wherein the crossing region C1 is one adjacent to the electrode formed in the first cutting step among both ends of the second body portion of the electrode formed in the second cutting step in the second length L2 direction. A method of manufacturing an electrode formed at the tip.
[Claim 6]
The method according to claim 4, wherein in the electrode formed in the first cutting step and the second cutting step, the first direction (D1) and the second direction (D2) are perpendicular to each other.
[Claim 7]
The method according to claim 1, wherein in the first cutting step and the second cutting step, the electrodes are each formed in plurality.
[Claim 8]
The method according to claim 7, The electrode formed in the first cutting step and the second cutting step includes an electrode tab having a shape protruding in one direction, and a plurality of each formed in the first cutting step and the second cutting step. At least some of the plurality of electrode tabs formed on the electrode protrude in opposite directions to each other.
[Claim 9]
The electrode as set forth in claim 5, wherein the electrode formed in the first cutting step and the electrode formed in the second cutting step are in contact with an overlapping region of the first cutting line (N1) and the second cutting line (N2) as a boundary. manufacturing method.
[Claim 10]
a first body portion having a first width (W1) and extending by a first length (L1) in a first direction (D1); and a second body portion having a second width (W2) smaller than the first length (L1) and extending from one end of the first body portion by a second length (L2) in a second direction (D2); Including, at least one of the corners of one end of the second body portion in the second length (L2) direction is formed with a region where two straight lines meet, and one end of any one of the two straight lines is connected to a curved line , The one straight line is a secondary battery electrode connected to the curve and a tangent line.
[Claim 11]
The electrode for a secondary battery of claim 10 , wherein the angle (θ) where the two straight lines meet is an obtuse angle.