Title of the invention: Pouch-type battery case and manufacturing apparatus for manufacturing the same, pouch-type secondary battery
technical field
[One]
Cross Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0114298 dated September 17, 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 a pouch-type battery case, a manufacturing apparatus for manufacturing the same, and a pouch-type secondary battery, and more particularly, to a pouch-type battery case having improved durability and preventing the occurrence of cracks and whitening during molding and a manufacturing apparatus for manufacturing the same, and to a pouch-type secondary battery.
background
[5]
In general, types of secondary batteries include a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and a lithium ion polymer battery. These secondary batteries are not only used in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, Portable Game Devices, Power Tools and E-bikes, but also in large products requiring high output such as electric and hybrid vehicles and surplus power generation. It is also applied and used in power storage devices that store power or renewable energy and power storage devices for backup.
[6]
In order to manufacture such a secondary battery, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to prepare a positive electrode and a negative electrode, and by laminating them on both sides of a separator, an electrode assembly having a predetermined shape (Electrode Assembly) to form Then, the electrode assembly is accommodated in the battery case and sealed after electrolyte injection.
[7]
The secondary battery is classified into a pouch type, a can type, and the like, according to a material of a case for accommodating the electrode assembly. The pouch type accommodates the electrode assembly in a pouch made of a flexible polymer material. In addition, the can type accommodates the electrode assembly in a case made of a material such as metal or plastic.
[8]
A pouch, which is a case of a pouch-type secondary battery, is manufactured by performing press working on a flexible pouch film to form a cup portion. Then, when the cup portion is formed, the electrode assembly is accommodated in the accommodating space of the cup portion and the side is sealed to manufacture a secondary battery.
[9]
Among these press working, drawing forming is performed by inserting a pouch film into a forming apparatus such as press equipment, applying pressure to the pouch film with a punch, and stretching the pouch film. However, since the pouch film is in the form of a film or sheet having a fairly thin thickness, stress was concentrated at the edges and corners when the pouch film was stretched. Therefore, there is a problem that cracks or whitening occurs in the pouch film.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[10]
An object of the present invention is to provide a pouch-type battery case capable of preventing the occurrence of cracks and whitening during molding, a manufacturing apparatus for manufacturing the same, and a pouch-type secondary battery.
[11]
The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.
means of solving the problem
[12]
In a pouch-type battery case according to an embodiment of the present invention for solving the above problems, a cup portion for accommodating an electrode assembly formed by stacking electrodes and a separator is formed therein, the cup portion comprising: a bottom portion forming a bottom; an outer wall forming a side surface and meeting the bottom part; a punch edge connecting the bottom and the outer wall, respectively; a thickness edge connecting the two adjacent outer walls to each other; and a corner formed by connecting two adjacent punch edges and the thickness edge, wherein at least one of the punch edges is rounded, and the thickness edge is formed by rounding at least one, and the corner is , at least one is rounded, and a radius of curvature is different from a radius of curvature of the punch edge and the thickness edge.
[13]
In addition, the corner may have a radius of curvature equal to or greater than a radius of curvature of at least one of the punch edge and the thickness edge.
[14]
In addition, the corner, the radius of curvature may change inside.
[15]
Also, in the corner, a radius of curvature of the central portion may be greater than a radius of curvature of the peripheral portion.
[16]
In addition, the punch edge may have a radius of curvature of 2 mm or less.
[17]
In addition, the thickness edge may have a radius of curvature of 0.5 mm to 5 mm.
[18]
In addition, the thickness edge, the radius of curvature may be formed to be greater than the radius of curvature of the punch edge.
[19]
In addition, the corner may be formed within a predetermined range from the thickness edge in the longitudinal direction and the width direction of the cup portion, and in the thickness direction from the punch edge.
[20]
In addition, the range in which the corner is formed may be formed wider as the depth of the cup part increases.
[21]
In addition, a perimeter connecting the two adjacent punch edges among the perimeters of the corner may be formed in a curved shape.
[22]
In addition, a circumference connecting the punch edge and the thickness edge among the circumferences of the corners may be formed in a curved shape.
[23]
In addition, the circumference connecting the two adjacent punch edges among the circumference of the corner may include at least one straight line.
[24]
In addition, a circumference connecting the punch edge and the thickness edge among the circumferences of the corners may include at least one straight line.
[25]
The apparatus for manufacturing a pouch-type battery case according to an embodiment of the present invention for solving the above problems includes a punch for forming a cup portion having a shape recessed in the pouch-type battery case by pressing the pouch film, wherein the punch has a bottom a pressure bottom to form; a pressing outer wall formed to meet the pressing bottom and forming a side surface; a pressing edge connecting the pressing bottom and the pressing outer wall to each other; a pressing thickness portion connecting the two adjacent pressing outer walls to each other; and a pressing corner formed by connecting two adjacent pressing edges and a pressing thickness portion, wherein at least one of the pressing corners is rounded, and a radius of curvature is different from the radius of curvature of the pressing edge and the pressing thickness portion.
[26]
The present invention also provides a secondary battery including the pouch-type battery case.
[27]
Other specific details of the invention are included in the detailed description and drawings.
Effects of the Invention
[28]
According to the embodiments of the present invention, there are at least the following effects.
[29]
When the pouch film is molded to manufacture the battery case, at least one corner of the cup part is rounded and formed, so the durability of the battery case is improved, and the occurrence of cracks and whitening during the molding of the pouch film can be prevented. .
[30]
The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.
Brief description of the drawing
[31]
1 is an enlarged perspective view illustrating a corner formed in a cup portion formed in a battery case according to the prior art and its surroundings.
[32]
2 is a perspective view showing the cup part 100 formed in the pouch-type battery case 10 according to the present invention.
[33]
3 is an enlarged perspective view illustrating the corner 150 formed in the cup part 100 formed in the battery case 10 according to an embodiment of the present invention.
[34]
4 is an enlarged perspective view showing the corner 150 formed in the cup part 100 formed in the battery case 10 according to another embodiment of the present invention.
[35]
5 is a vertical cross-sectional view showing the structure of the battery case manufacturing apparatus 20 according to the present invention.
Modes for carrying out the invention
[36]
Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.
[37]
Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.
[38]
The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.
[39]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[40]
[41]
pouch type battery case
[42]
1 is an enlarged perspective view illustrating a corner formed in a cup portion formed in a battery case according to the prior art and its surroundings.
[43]
Conventionally, all of the plurality of edges of the punch were rounded with the same radius of curvature, and accordingly, the corners of the punch were also naturally rounded with the same radius of curvature. Therefore, when the pouch film is stretched by forming the pouch film with such a punch, the corner is naturally rounded with the same radius of curvature as the punch edge.
[44]
Accordingly, as shown in FIG. 1, in the cup portion formed in the pouch-type battery case according to the prior art, the radius of curvature of the first punch edge A1, the radius of curvature of the second punch edge A2, and the first punch edge The radius of curvature of the first corner A3 connecting (A1) and the second punch edge A2 was equal to each other.
[45]
However, when the pouch film is stretched, stress is concentrated and there is a problem in that the thickness of the pouch film is reduced. In particular, since the corner is formed by the meeting of three edges, that is, two punch edges and one thick edge, it is stretched more than the punch edge or the thick edge, and the stress is concentrated more than the punch edge or the thick edge. This is that in FIG. 1 , the directions in which the first punch edge A1 and the second punch edge A2 extend are referred to as the first vector and the second vector, respectively, and the direction in which the first thickness edge A4 extends is referred to as the third vector. This is because, at the corner A3, stretching occurs in a direction in which a vector obtained by adding the first vector, the second vector, and the third vector is directed.
[46]
Therefore, as shown in FIG. 1, since the pouch film is stretched excessively, durability is lowered in the area corresponding to the corner, and a whitening phenomenon in which a specific part changes to white just before cracks occurred, eventually There was a problem that cracks easily occur.
[47]
Here, with respect to the occurrence of cracks, based on the residual ratio of the aluminum alloy included in the pouch film, if the residual ratio is 60% or more, it is judged as a good product, and if the residual ratio is less than 60%, it is judged as defective. The residual ratio means a ratio of the residual amount after molding to the residual amount before molding of the aluminum alloy at a specific point of the pouch film. In fact, when the residual ratio is less than 60%, when the cup part 100 is draw-molded on the pouch film, the frequency of cracks occurring at a specific point is high, but when the residual ratio is 60% or more, cracks do not occur. Therefore, hereinafter, the fact that cracks can easily occur means that the residual rate is relatively low and the frequency of occurrence of cracks is high.
[48]
2 is a perspective view showing the cup part 100 formed in the pouch-type battery case 10 according to the present invention.
[49]
The present invention may be an invention for solving the above problems according to the prior art. That is, according to the present invention, when the battery case 10 is manufactured by molding the pouch film, at least one corner 150 of the cup part 100 is rounded and formed, so that the durability of the battery case 10 is improved, It is possible to prevent the occurrence of cracks and whitening during the molding of the pouch film.
[50]
To this end, in the pouch-type battery case 10 according to an embodiment of the present invention, a cup part 100 for accommodating an electrode assembly formed by stacking electrodes and a separator therein is formed, and the cup part 100 has a bottom. forming a bottom portion (110); an outer wall 120 forming a side surface and meeting the bottom part 110; a punch edge 130 connecting the bottom 110 and the outer wall 120, respectively; a thickness edge 140 connecting the two adjacent outer walls 120 to each other; and a corner 150 formed by connecting the two adjacent punch edges 130 and the thickness edge 140 to each other, wherein the corner 150 is formed by rounding at least one, and a radius of curvature of the punch It is different from the radius of curvature of the edge 130 and the thickness edge 140 .
[51]
As shown in FIG. 2 , the pouch-type battery case 10 is manufactured by drawing-molding a pouch film in the form of a film or sheet. Such a pouch film may have a plurality of layered structures in which each layer is made of a different material.
[52]
As shown in FIG. 2 , the battery case 10 may include a cup part 100 having a downwardly recessed shape. The cup part 100 may be a space in which an electrode assembly (not shown) including an electrode and a separator is accommodated. 2 shows a state in which one cup part 100 is formed in the battery case 10 , but unlike this, a plurality of cup parts 100 may be formed in the battery case 10 , and a plurality of cup parts 100 are formed in the battery case 10 . The electrode assembly may be accommodated in the empty space formed by the .
[53]
The cup part 100 may include a bottom part 110 forming a bottom, and an outer wall 120 forming a side surface of the cup part 100 and meeting the bottom part 110 . As shown in FIG. 1 , the perimeter of the bottom part 110 may have a rectangular shape, and the outer wall 120 may be formed to meet each corner forming the perimeter of the bottom part 110 . At this time, the fact that the perimeter of the bottom part 110 has a rectangular shape does not mean only the case where the perimeter of the bottom part 110 has a rectangular shape with a geometric meaning. It should be interpreted as including the case of having a shape.
[54]
As shown in FIG. 2 , when the perimeter of the bottom part 110 has a rectangular shape, the outer wall 120 includes the first outer wall 122 , the second outer wall 124 , the third outer wall 126 , and the fourth outer wall. (128).
[55]
The cup part 100 includes various types of edges, and in particular includes a punch edge 130 formed to correspond to the pressing edge of the punch 26 (shown in FIG. 5 ). The punch edge 130 may connect the bottom part 110 and the outer wall 120 of the cup part 100, respectively, to form a boundary between the bottom part 110 and the outer wall 120 . As shown in FIG. 2 , a first punch edge 132 may be formed in a region where the bottom portion 110 and the first outer wall 122 meet each other, and the bottom portion 110 and the second outer wall 124 . A second punch edge 134 may be formed in the area where they meet each other. In addition, a third punch edge 136 may be formed in a region where the bottom part 110 and the third outer wall 126 meet each other, and the third punch edge 136 may be formed in a region where the bottom part 110 and the fourth outer wall 128 meet each other. Four punch edges 138 may be formed.
[56]
If the pressing edge of the punch 26 is not subjected to rounding treatment, the pressing edge of the punch 26 becomes sharp, so that when the pouch film is formed, stress is concentrated on the punch edge 130 of the cup part 100 to easily crack. There is a problem that arises. Therefore, according to an embodiment of the present invention, by performing a rounding process on the pressing edge of the punch 26, at least one of the punch edge 130 of the cup part 100 may be formed while being rounded convexly protruding to the outside. Thereby, the stress concentrated on the punch edge 130 of the cup part 100 can also be dispersed. Here, the radius of curvature of the punch edge 130 may be defined as the radius of curvature around the cross-section when the punch edge 130 is cut in a direction perpendicular to the direction in which the punch edge 130 extends. The punch edge 130 may have a radius of curvature of 2 mm or less, in particular 0.7 mm or less.
[57]
Punch edges 130 adjacent to each other may meet each other perpendicularly. That is, as shown in FIG. 2 , the first punch edge 132 and the second punch edge 134 , the second punch edge 134 and the third punch edge 136 , the third punch edge 136 and The fourth punch edge 138 , the fourth punch edge 138 and the first punch edge 132 may meet perpendicularly to each other.
[58]
In addition, the cup part 100 may include a thickness edge 140 connecting two outer walls 120 adjacent to each other. This thickness edge 140 is formed in the thickness direction of the cup part 100, and is formed while stretching between the corner of the die 22 (shown in FIG. 5) and the pressing corner of the punch 26 when the pouch film is stretched. . As shown in FIG. 2 , a first thickness edge 142 may be formed in a region where the first outer wall 122 and the second outer wall 124 meet each other, and the second outer wall 124 and the third outer wall ( A second thickness edge 144 may be formed in a region where 126 meet each other. In addition, a third thickness edge 146 may be formed in a region where the third outer wall 126 and the fourth outer wall 128 meet each other, and a region where the fourth outer wall 128 and the first outer wall 122 meet each other. The fourth thickness edge 148 may be formed. The first to fourth thickness edges 142 , 144 , 146 , and 148 may each have a thickness corresponding to the depth of the cup part 100 . More preferably, the length of the first to fourth thickness edges 142 , 144 , 146 , and 148 may be a value obtained by subtracting the width of the punch edge 130 from the depth of the cup part 100 . The lengths of the first to fourth thickness edges 142 , 144 , 146 , and 148 may be the same, but if the cup part 100 is asymmetrically formed, they may be different from each other.
[59]
According to an embodiment of the present invention, the thickness edge 140 of the cup part 100 may also be formed to be rounded convexly protruding outward. Thereby, the stress concentrated on the thickness edge 140 of the cup part 100 can also be dispersed. Here, the radius of curvature of the thickness edge 140 may be defined as the radius of curvature around the cross-section when the thickness edge 140 is cut in a direction perpendicular to the direction in which the thickness edge 140 extends.
[60]
And according to an embodiment of the present invention, the thickness edge 140 may have a radius of curvature that is different from the radius of curvature of the two punch edges 130 adjacent to each other. The thickness edge 140 may have a radius of curvature of 0.5 mm to 5 mm, particularly 0.5 mm to 3 mm, and the thickness edge 140 may have a radius of curvature greater than or equal to the radius of curvature of the punch edge 130 .
[61]
3 is an enlarged perspective view illustrating the corner 150 formed in the cup part 100 formed in the battery case 10 according to an embodiment of the present invention.
[62]
Meanwhile, unlike FIG. 2 , in FIG. 3 , the cup part 100 is illustrated as having a shape protruding toward the ground, and this illustration is for convenience of explanation and understanding. That is, FIG. 3 can be seen as an enlarged view of the first corner 152 and its periphery shown in FIG. 2 when viewed from the bottom of the battery case 10 .
[63]
As shown in FIG. 3 , the cup part 100 may include a corner 150 formed by connecting two punch edges 130 and a thickness edge 140 adjacent to each other. That is, a first corner 152 may be formed in a region where the first punch edge 132 and the second punch edge 134 and the first thickness edge 142 meet each other, and the second punch edge 134 and A second corner 154 may be formed in a region where the third punch edge 136 and the second thickness edge 144 meet each other. In addition, a third corner 156 may be formed in a region where the third punch edge 136 and the fourth punch edge 138 and the third thickness edge 146 meet each other, and the fourth punch edge 138 and A fourth corner 158 may be formed in a region where the first punch edge 132 and the fourth thickness edge 148 meet each other. And, as shown in Figure 3, the first punch edge 132, the second punch edge 134, the first thickness edge 142 and the first corner 152 may not have a concave recessed region. have.
[64]
As described above, if the pressing corner of the punch 26 is not subjected to a rounding treatment, the pressing corner of the punch 26 becomes sharp, so that the stress is concentrated on the corner 150 of the cup part 100 when the pouch film is molded. There is a problem that cracks easily occur. Therefore, according to an embodiment of the present invention, by rounding the pressing corner of the punch 26, at least one corner 150 of the cup part 100 is formed to protrude outward and rounded. In this case, the corner 150 may have a radius of curvature different from that of at least one of the punch edge 130 and the thickness edge 140 . In particular, the corner 150 may have a radius of curvature equal to or greater than the radius of curvature of at least one of the punch edge 130 and the thickness edge 140 . For example, as shown in FIG. 3 , the radius of curvature of the first corner 152 is the radius of curvature of at least one of the first punch edge 132 , the second punch edge 134 , and the first thickness edge 142 . may be more than In this way, the stress concentrating on the corner 150 of the cup part 100 can be dispersed.
[65]
Furthermore, according to an embodiment of the present invention, the radius of curvature of the corner 150 may be changed inside. That is, the radius of curvature of the center of the corner 150 and the radius of curvature of the periphery of the corner 150 may be different from each other. In particular, the radius of curvature of the center of the corner 150 may be greater than the radius of curvature of the periphery of the corner 150 . For example, as shown in FIG. 3 , the radius of curvature of the perimeter 1522 of the first corner 152 is a first punch edge 132 , a second punch edge 134 and a first thickness edge 142 . Since it is relatively adjacent to the first punch edge 132 , the second punch edge 134 , and the first thickness edge 142 may be the same as the radius of curvature of at least one. On the other hand, since the radius of curvature of the center 1521 of the corner 150 is relatively spaced apart from the first punch edge 132, the second punch edge 134 and the first thickness edge 142, the first punch edge ( 132 ), the second punch edge 134 , and the first thickness edge 142 may be larger than a radius of curvature of at least one of the edges 142 .
[66]
Accordingly, the corner 150 may have a radius of curvature equal to or greater than the radius of curvature of at least one of the punch edge 130 and the thickness edge 140 . In addition, the radius of curvature of the corner 150 may gradually increase from the periphery of the corner 150 toward the center of the corner 150 . Also, as described above, since the radius of curvature inside the corner 150 is not constant and changes, the center of the corner 150 may have an aspherical shape rather than an accurate spherical shape.
[67]
Unlike the punch edge 130 , the corner 150 must be clearly set not only with a radius of curvature, but also with a range formed in the cup part 100 . If the range in which the corner 150 is formed in the cup part 100 is excessively narrow, there is a problem in that the pouch film is still stretched excessively, resulting in whitening or cracking. On the other hand, if the range in which the corner 150 is formed in the cup part 100 is excessively wide, the space 17 between the outer wall 120 of the cup part 100 and the electrode assembly 10 decreases, so the rechargeable battery 1 ) can increase the energy density relative to the volume. In particular, according to an embodiment of the present invention, as shown in FIG. 3 , the corner 150 is the length direction lc and the width direction wc of the cup portion 100 from the thickness edge 140 , the punch edge 130 . All of them in the thickness direction dc of the cup part 100 may be formed within a predetermined range. And the range in which the corner 150 is formed may be formed wider as the depth of the cup part 100 increases. Since the corner 150 of the cup part 100 is formed in this way, stress that is more concentrated in the corner 150 may be dispersed, thereby preventing the problem of whitening and cracks occurring.
[68]
Meanwhile, as shown in FIG. 3 , according to an embodiment of the present invention, a perimeter connecting two punch edges 130 adjacent to each other among the perimeters of the corner 150 may be formed in a curved shape. In addition, the circumference connecting the punch edge 130 and the thickness edge 140 among the circumference of the corner 150 may also be formed in a curved shape. In this case, since the utilization of the internal space of the battery case 10 may increase, the capacity per unit volume of the secondary battery to which the battery case 10 is applied may increase.
[69]
4 is an enlarged perspective view showing the corner 150 formed in the cup part 100 formed in the battery case 10 according to another embodiment of the present invention.
[70]
According to another embodiment of the present invention as shown in Figure 4, the perimeter connecting the two adjacent punch edges 130 of the perimeter of the corner 150 may include at least one straight line. In addition, the circumference connecting the punch edge 130 and the thickness edge 140 among the circumference of the corner 150 may also include at least one straight line. In this case, there may be an advantage in terms of simplification of the process for manufacturing the battery case 10 .
[71]
On the other hand, with reference to FIGS. 3 and 4 , the above-described content for the first punch edge 132 and the second punch edge 134 is the same for the third punch edge 136 and the fourth punch edge 138 . It may be applied, and the contents of the first thick edge 142 may be equally applied to the second to fourth thick edges 144 , 146 , and 148 . Also, the contents of the first corner 152 may be equally applied to the second to fourth corners 154 , 156 , and 158 .
[72]
[73]
secondary battery
[74]
Meanwhile, the secondary battery according to the present invention may include an electrode assembly having a structure in which electrodes and separators are alternately disposed, and a battery case 10 accommodating the electrode assembly. At this time, the fact that the electrode assembly has a structure in which the electrodes and the separator are alternately arranged means that the electrode and the separator are alternately arranged when the electrode assembly is cut vertically, which limits the manufacturing method of the electrode assembly. it is not
[75]
Meanwhile, the contents of the battery case 10 will be replaced with the above contents with reference to the drawings.
[76]
[77]
battery case manufacturing device
[78]
5 is a vertical cross-sectional view showing the structure of the battery case manufacturing apparatus 20 according to the present invention.
[79]
The battery case manufacturing apparatus 20 according to an embodiment of the present invention includes a punch 26 for forming the cup part 100 having a shape recessed in the pouch-type battery case by pressing the pouch film, and the punch 26 ) is a pressurized bottom forming a bottom; a pressing outer wall formed to meet the pressing bottom and forming a side surface; a pressing edge connecting the pressing bottom and the pressing outer wall to each other; a pressing thickness portion connecting the two adjacent pressing outer walls to each other; and a pressing corner formed by connecting two adjacent pressing edges and a pressing thickness portion, wherein at least one of the pressing corners is rounded, and a radius of curvature is different from the radius of curvature of the pressing edge and the pressing thickness portion.
[80]
As shown in FIG. 5 , the battery case manufacturing apparatus 20 according to the present invention may include a die 22 and a stripper 24 . The die 22 and the stripper 24 may be configured to fix the pouch film in the process of forming the cup part 100 on the pouch film (not shown). That is, in order to form the cup part 100 on the pouch film, the regions other than the region pressed in the pouch film need to be fixed. The die 22 and the stripper 24 press the lower and upper surfaces of the pouch film, respectively. It may be a configuration for fixing the pouch film.
[81]
In addition, the battery case manufacturing apparatus 20 according to the present invention may further include a punch 26 for forming the cup part 100 having a recessed shape in the battery case 10 by pressing the pouch film. The punch 26 may be configured to be accommodated in a through hole formed in the central region of the upper fixing part 24 .
[82]
The area in which the cup part 100 is formed in the battery case 10 by pressing the pouch film with the punch 26 is the bottom 110 formed in the cup part 100 (refer to FIG. 1 ) of the battery case 10 described above, and the outer wall ( 120 ), the punch edge 130 , the thickness edge 140 , and the shape of the corner 150 may have a corresponding shape. Accordingly, the region in which the cup part 100 is formed in the battery case 10 by pressing the pouch film with the punch 26 is the bottom 110 formed in the cup part 100 of the battery case, the outer wall 120, and the punch. The shape of the edge 130 , the thickness edge 140 , and the corner 150 may be the same.
[83]
On the other hand, the punch 26 is formed to meet the bottom portion 110 of the cup portion 100 and is formed to meet the pressure bottom portion forming the bottom of the punch 26, and the outer wall 120 of the cup portion 100, It may include a pressurized outer wall forming the side of the punch 26 . The pressing bottom and the pressing outer wall of the punch 26 are configured to press the bottom 110 (see FIG. 1) and the outer wall 120 (see FIG. 1) of the cup part 100 of the battery case 10 described above, It may have a shape corresponding to the bottom part 110 and the outer wall 120 of the cup part 100 .
[84]
On the other hand, the pressurized outer wall may include a plurality of pressurized outer walls, the first to fourth pressurized outer walls are the first to fourth outer walls (122, 124, 126, 128, see Fig. 1) of the cup portion 100 described above. Each may have a corresponding shape.
[85]
The punch 26 may include a pressing edge connecting the pressing bottom and the pressing outer wall to each other. The pressing edge may have a shape corresponding to the punch edge 130 (refer to FIG. 1 ) of the cup part 100 described above. That is, in the area where the pressing bottom and the first to fourth pressing outer walls meet each other, shapes corresponding to the first to fourth punch edges 132, 134, 136, 138, respectively, of the cup part 100 (see FIG. 1) are formed. The branch may have first to fourth pressing edges, respectively. Accordingly, at least one of the pressing edges may be convexly protruded to the outside to be rounded.
[86]
Further, the punch 26 may include a pressing thickness portion connecting two adjacent pressing outer walls to each other. The pressure thickness portion may have a shape corresponding to the thickness edge 140 (refer to FIG. 1 ) of the cup portion 100 described above. That is, the first to fourth pressing thickness portions may have shapes respectively corresponding to the first to fourth thickness edges 142 , 144 , 146 , 148 (refer to FIG. 1 ) of the cup part 100 . Accordingly, at least one of the pressing thickness portions may be convexly protruded to the outside to be rounded.
[87]
In addition, the punch 26 may include a pressing corner formed by connecting two pressing edges adjacent to each other and a pressing thickness portion. The pressing corner may have a shape corresponding to the corner 150 of the cup part 100 described above. That is, the first to fourth pressing corners may have shapes corresponding to the first to fourth corners 152 , 154 , 156 , 158 (refer to FIG. 1 ) of the cup part 100 , respectively. Accordingly, at least one of the pressing corners may be convexly protruded to the outside to be rounded.
[88]
The pressing edge, the pressing thickness portion, and the pressing corner may each have a predetermined radius of curvature and may be convexly protruded to the outside to be rounded. And, the radius of curvature of the pressing edge may correspond to the radius of curvature of the punch edge 130 of the cup part 100 described above, and the radius of curvature of the pressing thickness part is the radius of curvature of the thickness edge 140 of the cup part 100 described above. may correspond to, and the radius of curvature of the pressing corner may correspond to the radius of curvature of the corner 150 of the cup part 100 described above.
[89]
According to an embodiment of the present invention, the thickness edge 140 has a radius of curvature different from the radius of curvature of the punch edge 130 , and in particular, since it may be formed to be greater than or equal to the radius of curvature of the punch edge 130 , the curvature of the pressed thickness portion The radius is different from the radius of curvature of the pressing edge, and in particular may be formed to be greater than or equal to the radius of curvature of the pressing edge.
[90]
And the corner 150 has a radius of curvature different from the radius of curvature of at least one of the punch edge 130 and the thickness edge 140, and in particular, the radius of curvature of at least one of the punch edge 130 and the thickness edge 140. Therefore, the pressing corner has a radius of curvature that is different from the radius of curvature of at least one of the pressing edge and the pressing thickness portion, and in particular, may be formed to be greater than or equal to the radius of curvature of at least one of the pressing edge and the pressing thickness portion.
[91]
Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.
Claims
[Claim 1]
A cup portion for accommodating an electrode assembly formed by stacking electrodes and a separator therein is formed, wherein the cup portion includes: a bottom portion forming a bottom; an outer wall forming a side surface and meeting the bottom part; a punch edge connecting the bottom and the outer wall, respectively; a thickness edge connecting the two adjacent outer walls to each other; and a corner formed by connecting two adjacent punch edges and the thickness edge, wherein at least one of the punch edges is rounded, and the thickness edge is formed by rounding at least one, and the corner is , at least one is rounded and formed, and the radius of curvature is different from the radius of curvature of the punch edge and the thickness edge.
[Claim 2]
The pouch-type battery case of claim 1, wherein the corner has a radius of curvature equal to or greater than a radius of curvature of at least one of the punch edge and the thickness edge.
[Claim 3]
The pouch-type battery case of claim 2, wherein the corner has a different radius of curvature inside it.
[Claim 4]
The pouch-type battery case of claim 3, wherein the corner has a radius of curvature of the central portion greater than the radius of curvature of the peripheral portion.
[Claim 5]
The pouch-type battery case of claim 1, wherein the punch edge has a radius of curvature of 2 mm or less.
[Claim 6]
The pouch-type battery case of claim 1, wherein the thickness edge has a radius of curvature of 0.5 mm to 5 mm.
[Claim 7]
The pouch-type battery case of claim 1, wherein the thickness edge has a radius of curvature greater than or equal to a radius of curvature of the punch edge.
[Claim 8]
The pouch-type battery case of claim 1 , wherein the corners are formed within a predetermined range from the thickness edge in the longitudinal direction and the width direction of the cup part, and in the thickness direction from the punch edge.
[Claim 9]
The pouch-type battery case according to claim 8, wherein a range in which the corners are formed becomes wider as the depth of the cup part increases.
[Claim 10]
The pouch-type battery case of claim 1, wherein a perimeter connecting two adjacent punch edges among perimeters of the corners is formed in a curved shape.
[Claim 11]
The pouch-type battery case of claim 1 , wherein a circumference connecting the punch edge and the thickness edge among the circumferences of the corners is formed in a curved shape.
[Claim 12]
The pouch-type battery case of claim 1 , wherein a perimeter connecting two adjacent punch edges among perimeters of the corner includes at least one straight line.
[Claim 13]
The pouch-type battery case of claim 1 , wherein a circumference connecting the punch edge and the thickness edge among the circumferences of the corners includes at least one straight line.
[Claim 14]
and a punch for forming a cup portion having a recessed shape in the pouch-type battery case by pressing the pouch film, wherein the punch includes: a pressure bottom portion forming a bottom; a pressing outer wall formed to meet the pressing bottom and forming a side surface; a pressing edge connecting the pressing bottom and the pressing outer wall to each other; a pressing thickness portion connecting the two adjacent pressing outer walls to each other; and a pressing corner formed by connecting two adjacent pressing edges and a pressing thickness portion, wherein at least one of the pressing corners is rounded, and the radius of curvature is different from the radius of curvature of the pressing edge and the pressing thickness part. Battery case manufacturing device.
[Claim 15]
A secondary battery comprising the pouch-type battery case according to claim 1.