Secondary battery pouch forming device and secondary battery pouch manufactured thereby

Abstract

The present invention relates to a secondary battery pouch forming device and a secondary battery pouch manufactured thereby, which allows the pouch bridge portion to stretch well when the pouch is folded, thereby preventing damage to the cells, improving cell positioning accuracy, and preventing wrinkles from forming in the cell seal portion, thereby producing high-quality secondary batteries.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0110313, filed on August 31, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a secondary battery pouch forming device and a secondary battery pouch manufactured thereby, which allows the pouch bridge portion to stretch well when the pouch is folded, thereby preventing damage to the cells, improving cell positioning accuracy, and preventing wrinkles from forming in the cell seal portion, thereby producing high-quality secondary batteries. [Background technology]

[0003] In recent years, with the depletion of fossil fuels causing rising energy prices and increasing concerns about environmental pollution, the demand for environmentally friendly alternative energy sources has become an essential factor for future life. Therefore, research into various electricity production technologies such as solar, wind, and tidal power has continued, and there has also been great interest in power storage devices such as batteries to more efficiently use the electrical energy produced in this way.

[0004] Furthermore, with the increasing technological development and demand for battery-based electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly increasing, and as a result, much research is being conducted on batteries that can meet various demands.

[0005] In particular, there is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries, which have advantages in terms of materials such as high energy density, discharge voltage, and output stability.

[0006] Depending on the shape of the battery case, secondary batteries can be classified into cylindrical batteries and prismatic batteries in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch batteries in which the electrode assembly is housed in a pouch-shaped case made of an aluminum laminate sheet.

[0007] Fig. 1 is a cross-sectional view showing a portion of a conventional pouch-type secondary battery, specifically, a cross-sectional view showing a secondary battery pouch and an electrode assembly contained therein.

[0008] The pouch-type secondary battery 1 includes an electrode assembly 20 formed by alternately stacking electrodes and separators, and a pouch 10 into which the electrode assembly is inserted. The pouch includes cup portions 11 and 12 having a recessed shape to directly accommodate the electrode assembly. The pouch cup portion may be provided with a left cup portion 11 and a right cup portion 12 to surround the electrode assembly from both sides.

[0009] The portion connecting the left cup portion 11 and the right cup portion 12 to each other may be a pouch bridge portion 13. The left cup portion 11 may be folded onto the top of the right cup portion 12 around the pouch bridge portion 13. Through this folding process, the pouch cup portions 11 and 12 form a receiving space, and the electrode assembly 20 may be received in this receiving space.

[0010] Referring to FIG. 1 , in the past, when the left cup portion 11 was folded over the right cup portion 12, the pouch bridge portion 13 did not stretch well. As the capacity of secondary batteries increased, the pouch depth increased, resulting in an increase in the thickness of the pouch. This resulted in a problem of the pouch bridge portion 13 not stretching well when the pouch was folded after being formed, as shown in FIG. 1 . If the pouch bridge portion 13 did not stretch well and protruded toward the electrode assembly 20, cell damage could occur due to the pouch bridge portion 13 damaging the electrode assembly 20. Furthermore, if the pouch bridge portion 13 did not stretch well, the cell's appearance would not be precisely formed, making it difficult to accurately measure its position using a vision camera or the like. This could result in reduced positional accuracy. Furthermore, if the pouch bridge portion 13 did not stretch well, the reduced accuracy could lead to wrinkles when sealing the periphery of the pouch. Therefore, there was a strong need to ensure that the pouch bridge portion 13 stretches well when the pouch is folded. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the problems described above, and the object of the present invention is to provide a secondary battery pouch molding device and a secondary battery pouch manufactured by the device, which allows the pouch bridge portion to stretch well when the pouch is folded, thereby preventing damage to the cells, improving cell positioning accuracy, and preventing wrinkles from forming in the cell seal portion, thereby producing secondary batteries of high quality. [Means for solving the problem]

[0012] The secondary battery pouch molding device of the present invention includes a die having a storage groove formed on a base surface on which the pouch is placed for forming the cup portion of the pouch, and a punch that is inserted into the storage groove of the die and forms the cup portion of the pouch, the die including a left side storage groove portion having a concave shape, a right side storage groove portion having a concave shape formed on the side of the left side storage groove portion, and a bridge portion that connects the left side storage groove portion and the right side storage groove portion between the left side storage groove portion and the right side storage groove portion, and the bridge portion is formed concavely so that the height of the center portion is lower than the height of both end portions based on the length direction.

[0013] The bridge portion may have a height that decreases continuously from both ends to the center.

[0014] The bridge portion may be formed such that a cross section cut along an imaginary vertical plane that passes through the bridge portion and separates the left and right receiving groove portions is partially or completely U-shaped.

[0015] The bridge portion may be formed such that a cross section cut along an imaginary vertical plane that passes through the bridge portion and separates the left and right receiving grooves is partially or entirely circular or elliptical.

[0016] The height of the center of the bridge portion may be 9 mm to 10 mm, and the heights of both ends of the bridge portion may be 11 mm to 12 mm.

[0017] The punch may include a punch protrusion having a protruding shape corresponding to the concave shape of the bridge portion.

[0018] The secondary battery pouch molding device of the present invention includes a die having a storage groove formed on a base surface on which the pouch is placed for forming the cup portion of the pouch, and a punch that is inserted into the storage groove of the die to form the cup portion of the pouch, the die including a left side storage groove portion having a concave shape, a right side storage groove portion having a concave shape formed on the side of the left side storage groove portion, and a bridge portion that connects the left side storage groove portion and the right side storage groove portion between the left side storage groove and the right side storage groove portion, and the left side storage groove portion and the right side storage groove portion have bottom surfaces that are formed horizontally in the central region and inclined in the end region, based on a direction parallel to the longitudinal direction of the bridge portion.

[0019] In the end regions, the bottom surfaces of the left and right receiving grooves may be formed to be inclined so that the height increases as they approach the bridge portion.

[0020] In the end regions, the bottom surfaces of the left and right storage grooves may be inclined at angles of 1 to 10 degrees with respect to the horizontal plane.

[0021] Each of the left and right storage grooves includes a bottom surface and a side wall surface extending upward from the periphery of the bottom surface, and the height of the side wall surface of the left storage groove measured based on the bottom surface of the left storage groove may be the same in the central region and both end regions.

[0022] The height of the side wall surface of the right receiving groove portion measured based on the bottom surface of the right receiving groove portion may be the same in the central region and both end regions.

[0023] The left and right receiving grooves may be formed symmetrically with respect to the bridge portion.

[0024] The secondary battery pouch molding device of the present invention includes a die having a storage groove formed on a base surface on which the pouch is placed for forming the cup portion of the pouch, and a punch that is inserted into the storage groove of the die to form the cup portion of the pouch, the die including a left side storage groove portion having a concave shape, a right side storage groove portion having a concave shape formed on the side of the left side storage groove portion, and a bridge portion that connects the left side storage groove portion and the right side storage groove portion between the left side storage groove and the right side storage groove portion, the bridge portion being formed concavely so that the height of the central portion is lower than the height of both end portions based on the longitudinal direction, and the left side storage groove portion and the right side storage groove portion are formed so that the bottom surfaces are horizontal in the central region and inclined in the both end regions based on a direction parallel to the longitudinal direction of the bridge portion.

[0025] The secondary battery pouch of the present invention includes a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed, and a pouch bridge portion between the left cup portion and the right cup portion that connects the two cup portions, and the pouch bridge portion is formed in a concave shape so that the height of the central portion is lower than the height of both end portions based on the longitudinal direction.

[0026] The height of the center of the pouch bridge portion may be 2 mm to 4 mm, and the heights of both ends of the pouch bridge portion may be 4 mm to 6 mm.

[0027] The secondary battery pouch of the present invention includes a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed, and a pouch bridge portion between the left cup portion and the right cup portion that connects the two cup portions, and the left cup portion and the right cup portion have bottom surfaces that are formed horizontally in the central region and inclined in the end region, based on a direction parallel to the longitudinal direction of the pouch bridge portion.

[0028] The secondary battery pouch of the present invention includes a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed, and a pouch bridge portion between the left cup portion and the right cup portion and connecting the two cup portions, wherein the pouch bridge portion is formed concavely so that the height of the central portion is lower than the height of both end portions based on the longitudinal direction, and the left cup portion and the right cup portion have bottom surfaces formed horizontally in the central region and inclined in the both end regions based on a direction parallel to the longitudinal direction of the pouch bridge portion. [Effects of the Invention]

[0029] The secondary battery pouch molding device of the present invention and the secondary battery pouch manufactured thereby allow the pouch bridge portion to stretch well when the pouch is folded, thereby preventing damage to the cells, improving cell positioning accuracy, and preventing wrinkles from forming in the cell seal portion, thereby enabling the production of high-quality secondary batteries. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a cross-sectional view showing a portion of a conventional pouch-type secondary battery. [Figure 2] FIG. 2 is a perspective view showing a die of the secondary battery pouch forming device according to the first embodiment of the present invention. [Figure 3] 3 is a cross-sectional view of the bridge portion taken along line CC' in FIG. 2. FIG. [Figure 4(a)] FIG. 2 is a perspective view showing a punch of the secondary battery pouch forming device according to the first embodiment of the present invention. [Figure 4(b)] FIG. 5 is a cross-sectional view of the punch shown in FIG. 4(a). [Figure 5] 1 is a perspective view showing a secondary battery pouch manufactured by a secondary battery pouch forming apparatus according to a first embodiment of the present invention. FIG. [Figure 6] FIG. 10 is a perspective view showing a die of a secondary battery pouch forming device according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view taken along the line S1 in FIG. 6. [Figure 8]FIG. 7 is a cross-sectional view taken along the lines S2 and S3 in FIG. 6. [Figure 9] FIG. 10 is a perspective view showing a secondary battery pouch manufactured by a secondary battery pouch forming apparatus according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view taken along the P1 position in FIG. 9. [Figure 11] 10 is a cross-sectional view taken along the lines P2 and P3 in FIG. 9. [Figure 12] FIG. 10 is a perspective view showing a die of a secondary battery pouch forming device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the preferred embodiments of the present invention. However, the present invention may be embodied in various different forms and is not limited to the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or related known technologies that may unnecessarily obscure the gist of the present invention will be omitted, and in this specification, when assigning reference symbols to components in each drawing, the same or similar reference symbols will be assigned to the same or similar components throughout the specification.

[0033] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best explain their inventions.

[0034] First embodiment Fig. 2 is a perspective view showing a die of the secondary battery pouch forming apparatus according to the first embodiment of the present invention. Fig. 3 is a cross-sectional view of the bridge portion taken along line CC' in Fig. 2. Fig. 4(a) is a perspective view showing a punch of the secondary battery pouch forming apparatus according to the first embodiment of the present invention, and Fig. 4(b) is a cross-sectional view of the punch shown in Fig. 4(a). Fig. 5 is a perspective view showing a secondary battery pouch manufactured by the secondary battery pouch forming apparatus according to the first embodiment of the present invention.

[0035] 2 to 5, a secondary battery pouch forming apparatus 100 according to a first embodiment of the present invention can include a die 110 and a punch 150.

[0036] The die 110 may have a base surface 113 on which the pouch rests, with a receiving groove formed therein for forming the cup portion 133 of the pouch.

[0037] Specifically, the die 110 includes a left-side storage groove portion 111 having a concave shape, a right-side storage groove portion 112 formed on the side of the left-side storage groove portion 111 and having a concave shape, and a bridge portion 120 connecting the left-side storage groove portion 111 and the right-side storage groove portion 112 between the left-side storage groove portion 111 and the right-side storage groove portion 112.

[0038] The punch 150 may be configured to be inserted into the receiving groove of the die 110 to form the cup portion of the pouch. A flat pouch base material may be placed on the base surface 113, and the punch 150 may be lowered to form the pouch. The punch 150 may form a pouch having a shape corresponding to the shape of the die 110. The punch 150 may be inserted into the concave groove of the die 110 to form the pouch. A pouch formed in this manner may have a shape similar to the secondary battery pouch 130 shown in FIG. 5.

[0039] In the secondary battery pouch forming apparatus 100 according to the first embodiment of the present invention, the bridge portion 120 is formed in a concave shape such that the height of the central portion 121 in the length direction (L) is lower than the height of both end portions 122. Referring to Figures 2 and 3, the height of the bridge portion 120 may continuously decrease from both end portions 122 to the central portion 121.

[0040] 3, the cross section of the bridge portion 120 cut along an imaginary vertical plane that passes through the bridge portion 120 and separates the left and right receiving grooves may have a partial or complete U-shape. When cut along the imaginary vertical plane, the cross section of the bridge portion 120 may have the shape shown in FIG. 3. As shown in FIG. 3, the cross section of the bridge portion 120 taken along line CC' may have a curved shape, and in particular, the cross section may have a partial or complete U-shape.

[0041] In addition, the bridge portion 120 may be formed such that a cross section cut along an imaginary vertical plane that passes through the bridge portion 120 and separates the left and right receiving grooves is partially or entirely circular or elliptical.

[0042] 3, the height (h1) of the central portion 121 of the bridge portion 120 may be 9 mm to 10 mm, and the height (h2) of each of the ends 122 of the bridge portion 120 may be 11 mm to 12 mm. As a result, the bridge portion 120 may have a shape in which the height of each of the ends 122 is even greater and the height decreases toward the central portion 121.

[0043] Referring to FIG. 4(a), the punch 150 may include a punch protrusion 151 having a protruding shape corresponding to the concave shape of the bridge portion 120. The punch protrusion 151 may be a portion located at a position corresponding to the bridge portion 120 of the die 110. A pouch base material may be positioned and pressed between the punch protrusion 151 and the bridge portion 120 of the die 110. As a result, the pouch bridge portion 140 may be formed into a shape corresponding to the shape of the bridge portion 120 of the die 110. If the portion of the punch 150 corresponding to the bridge portion 120 is flat rather than protruding, the space at the center portion 121 may be insufficient compared to both ends 122 of the bridge portion 120. Therefore, when the punch 150 is formed into a protruding shape, such as a U-shape, the height difference can be compensated for.

[0044] 4(b) shows a cross section of the punch protrusion 151 shown in FIG. 4(a). The cross section of the punch protrusion 151 may have a shape corresponding to the cross section of the bridge portion 120 of the die 110. That is, the cross section of the punch protrusion 151 may be formed in a shape such as a partial or complete U-shape, or may be formed in a shape such as a partial or complete circle or ellipse.

[0045] When a pouch is formed using the secondary battery pouch forming apparatus 100 described above, the secondary battery pouch 130 shown in FIG. 5 can be manufactured.

[0046] Referring to FIG. 5, the secondary battery pouch 130 manufactured by the secondary battery pouch forming apparatus 100 according to the first embodiment of the present invention may include a pouch cup portion 133 and a pouch bridge portion 140.

[0047] Here, the pouch cup portion 133 may include two cup portions, a left cup portion 131 and a right cup portion 132. The pouch cup portion 133 may be configured to have two cup portions, a left cup portion 131 and a right cup portion 132. The pouch bridge portion 140 may be configured to connect the two cup portions between the left cup portion 131 and the right cup portion 132.

[0048] The portion formed by the left storage groove portion 111 of the die 110 may be the left cup portion 131, and the portion formed by the right storage groove portion 112 may be the right cup portion 132. The portion formed by the bridge portion 120 of the die 110 may be the pouch bridge portion 140.

[0049] Therefore, the pouch bridge portion 140 of the secondary battery pouch 130 manufactured by the secondary battery pouch forming apparatus 100 according to the first embodiment of the present invention can be formed in a concave shape so that the height of the central portion 141 is lower than the height of both end portions 142 based on the length direction (L').

[0050] Specifically, the height of the central portion 141 of the pouch bridge portion may be 2 mm to 4 mm, and the height of both end portions 142 of the pouch bridge portion may be 4 mm to 6 mm. As a result, the pouch bridge portion may have a shape in which the height of both end portions 142 is even higher and the height decreases toward the central portion 141.

[0051] In the pouch bridge portion 140, when the height of the central portion 141 is formed in a concave shape so that the height of the end portions 142 is lower than the height of the end portions 142, the pouch bridge portion 140 can be easily stretched when the pouch is folded.

[0052] Referring to FIG. 1, conventionally, the pouch bridge portion 140 has a poor stretchability. That is, as shown in FIG. 1, the pouch bridge portion 140 has a shape that protrudes toward the inside (I) of the secondary battery, like a V-shape rotated 90 degrees counterclockwise. In this case, as shown in FIG. 1, interference occurs between the internal electrode assembly and the pouch bridge portion 140, which can result in damage to the electrode assembly. In particular, there is a problem in that the center portion 141 of the pouch bridge portion 140 does not stretch well. Since both end portions 142 of the pouch bridge portion 140 have outer corners, they are subjected to stronger tension during folding and stretch well, whereas the center portion 141 receives less tension and does not stretch well.

[0053] However, in the secondary battery pouch 130 manufactured by the secondary battery pouch forming apparatus 100 according to the present invention, the width of the pouch bridge portion 140 at the center 141 of the pouch bridge portion 140 may be formed relatively shorter. That is, both end portions 142 of the pouch bridge portion 140 formed by the higher portions of the bridge portion 120 of the die 110 may be formed with a longer width, and the center portion 141 of the pouch bridge portion 140 formed by the lower portions of the bridge portion 120 of the die 110 may be formed with a shorter width. Therefore, the center portion 141 of the pouch bridge portion 140 can stretch more even when a small tension is applied during folding.

[0054] Therefore, in the secondary battery pouch 130 manufactured by the secondary battery pouch forming apparatus 100 according to the first embodiment of the present invention, the pouch bridge portion 140 can stretch significantly when the pouch is folded. In this case, compared to the pouch shown in Fig. 1, the pouch bridge portion 140 can move further outward (E) and stretch in a straight line. This prevents interference with the electrode assembly, thereby preventing damage to the electrode assembly.

[0055] In addition to preventing damage to the electrode assembly and the resulting damage to the cells, the secondary battery pouch forming device and secondary battery according to the first embodiment of the present invention can also achieve the effects of improving cell positioning accuracy and preventing wrinkles from forming in the cell seal portion.

[0056] When the pouch bridge portion 140 is stretchable, the appearance of the cell is precisely formed, allowing for precise position measurement using a vision camera or the like. This can improve positional accuracy. In addition, when the pouch bridge portion 140 is stretchable, the improved accuracy can prevent the problem of wrinkles occurring when sealing the periphery of the pouch.

[0057] As a result, the secondary battery pouch forming apparatus and secondary battery according to the first embodiment of the present invention can realize a secondary battery of excellent quality.

[0058] Second embodiment Fig. 6 is a perspective view showing a die of a secondary battery pouch forming apparatus according to a second embodiment of the present invention. Fig. 7 is a cross-sectional view taken at position S1 in Fig. 6. Fig. 8 is a cross-sectional view taken at positions S2 and S3 in Fig. 6. Fig. 9 is a perspective view showing a secondary battery pouch manufactured by the secondary battery pouch forming apparatus according to the second embodiment of the present invention. Fig. 10 is a cross-sectional view taken at position P1 in Fig. 9. Fig. 11 is a cross-sectional view taken at positions P2 and P3 in Fig. 9.

[0059] The second embodiment of the present invention differs from the first embodiment in that the left and right storage grooves of the die have a partly inclined bottom surface.

[0060] The second embodiment will be described focusing on the differences and omitting as much as possible the content common to the first embodiment. In other words, if content not explained in the second embodiment is necessary, it is clear that it can be regarded as the content of the first embodiment.

[0061] The secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention can include a die 210 and a punch.

[0062] The die 210 may have a base surface 213 on which the pouch is placed, and a receiving groove for forming the cup portion of the pouch formed on the base surface 213.

[0063] Specifically, the die 210 includes a left-side storage groove portion 211 having a concave shape, a right-side storage groove portion 212 formed on the side of the left-side storage groove portion 211 and having a concave shape, and a bridge portion 220 connecting the left-side storage groove portion 211 and the right-side storage groove portion 212 between the left-side storage groove portion 211 and the right-side storage groove portion 212.

[0064] The punch may be configured to be inserted into the receiving groove of the die 210 to form the cup portion of the pouch. The punch has a shape corresponding to the groove portion of the die 210, and can be inserted into the concave groove portion of the die 210 to form the pouch. The pouch formed in this manner can have a shape like the secondary battery pouch 230 shown in FIGS. 9 to 11.

[0065] Referring to Figure 6, in the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the left side accommodating groove portion 211 and the right side accommodating groove portion 212 are formed with a horizontal bottom surface in the central region 214 and an inclined bottom surface in both end regions 215, based on a direction parallel to the longitudinal direction (L) of the bridge portion 220.

[0066] Fig. 7 is a cross-sectional view taken at position S1 in Fig. 6. The cross-sectional view taken at position S1 may refer to a cross-sectional view taken at the central region 214. As shown in the cross-sectional view of Fig. 7, the bottom surface of the receiving groove in the central region 214 is not inclined, i.e., is formed horizontally.

[0067] 8 is a cross-sectional view taken along the S2 and S3 positions in FIG. 6. The cross-sectional view taken along the S2 and S3 positions may refer to a cross-sectional view taken along the both end regions 215. As shown in the cross-sectional view of FIG. 8, the bottom surfaces of the receiving grooves in the both end regions 215 are inclined. In the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the cross sections of the receiving grooves at the S2 and S3 positions may be the same, and this cross-sectional view may be the cross-sectional view shown in FIG. 8.

[0068] 8, in both end regions 215, bottom surface 211-1 of the left accommodating groove portion and bottom surface 212-1 of the right accommodating groove portion may be inclined so that their heights increase toward bridge portion 220. Specifically, in both end regions 215, the inclination angle (θ) formed by bottom surface 211-1 of the left accommodating groove portion and bottom surface 212-1 of the right accommodating groove portion with respect to the horizontal plane may be 1 to 10 degrees.

[0069] In the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the left-side accommodating groove 211 and the right-side accommodating groove 212 each include a bottom surface and a side wall surface 211-2 extending upward from the periphery of the bottom surface. Both the bottom surface and the side surface can be concave.

[0070] The height of the side wall surface 211-2 of the left receiving groove portion 211 measured based on the bottom surface 211-1 of the left receiving groove portion may be the same in the central region 214 and both end regions 215. This will be described in detail as follows.

[0071] 7, the height of the side wall surface 211-2 of the left accommodating groove portion 211 measured based on the bottom surface 211-1 of the left accommodating groove portion in the central region 214 may be t1. Then, referring to Fig. 8, the height of the side wall surface 211-2 of the left accommodating groove portion 211 measured based on the bottom surface 211-1 of the left accommodating groove portion in the both end regions 215 may be t2. In this case, t1 and t2 may have the same value (t1 = t2).

[0072] In the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the height of the side wall surface 211-2 of the right accommodating groove portion 212 measured based on the bottom surface 212-1 of the right accommodating groove portion may be the same in the central region 214 and the both end regions 215. This will be described in detail as follows.

[0073] 7, the height of the sidewall of the right accommodating groove 212 measured based on the bottom surface 212-1 of the right accommodating groove in the central region 214 may be t3. Then, referring to Fig. 8, the height of the sidewall of the right accommodating groove 212 measured based on the bottom surface 212-1 of the right accommodating groove in the both end regions 215 may be t4. In this case, t3 and t4 may have the same value (t3 = t4).

[0074] In the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the left accommodating groove 211 and the right accommodating groove 212 may be formed to have shapes symmetrical to each other with respect to the bridge portion 220. Specifically, being symmetrical to each other with respect to the bridge portion 220 may mean that the left accommodating groove 211 and the right accommodating groove 212 have shapes symmetrical to each other with respect to an imaginary plane that cuts the bridge portion 220 vertically.

[0075] In this case, t1 = t3 and t2 = t4 may be true. As mentioned above, t1 = t2 and t3 = t4, so that t1 = t2 = t3 = t4 can be true. That is, t1, t2, t3, and t4 can all have the same value.

[0076] When a pouch is formed using the secondary battery pouch forming apparatus 200 described above, the secondary battery pouch 230 shown in FIGS. 9 to 11 can be manufactured.

[0077] Referring to FIG. 9, a secondary battery pouch 230 manufactured by a secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention may include a pouch cup portion 233 and a pouch bridge portion 240.

[0078] Here, the pouch cup portion 233 may include two cup portions, a left cup portion 231 and a right cup portion 232. The pouch cup portion 233 may be configured to have two cup portions, a left cup portion 231 and a right cup portion 232. The pouch bridge portion 240 may be configured to connect the two cup portions between the left cup portion 231 and the right cup portion 232.

[0079] The portion formed by the left storage groove portion 211 of the die 210 may be the left cup portion 231, and the portion formed by the right storage groove portion 212 may be the right cup portion 232. The portion formed by the bridge portion 220 of the die 210 may be the pouch bridge portion 240.

[0080] 9 to 11, the left cup portion 231 and the right cup portion 232 have horizontal bottom surfaces in the central region 234 and inclined bottom surfaces in both end regions 235, based on a direction parallel to the length direction (L') of the pouch bridge portion 240. This is because the shape of the pouch cup portion 233 is formed to correspond to the shape of the receiving groove portion of the die 210.

[0081] Fig. 10 is a cross-sectional view taken at position P1 in Fig. 9. The cross-sectional view taken at position P1 may refer to a cross-sectional view taken at the central region 234. As shown in the cross-sectional view of Fig. 10, the bottom surface of the receiving groove in the central region 234 is not inclined, i.e., is formed horizontally.

[0082] 11 is a cross-sectional view taken along the P2 and P3 positions in FIG. 9. The cross-sectional view taken along the P2 and P3 positions may refer to a cross-sectional view taken along the both end regions 235. As shown in the cross-sectional view of FIG. 11, the bottom surfaces of the receiving grooves in the both end regions 235 are inclined. In the secondary battery pouch 230 manufactured by the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the cross sections of the receiving grooves at the P2 and P3 positions may be the same, and this cross-sectional view may be the cross-sectional view shown in FIG. 11.

[0083] 11, in both end regions 235, a bottom surface 231-1 of the left cup portion 231 and a bottom surface 232-1 of the right cup portion 232 may be inclined so that the height increases toward the pouch bridge portion 240. Specifically, in both end regions 235, the inclination angle (θ′) formed by the bottom surface 231-1 of the left cup portion 231 and the bottom surface 232-1 of the right cup portion 232 with respect to the horizontal plane may be 1 to 10 degrees.

[0084] In the secondary battery pouch 230 manufactured by the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the left cup portion 231 and the right cup portion 232 each include a bottom surface and a side wall surface 231-2 extending upward from the periphery of the bottom surface. Both the bottom surface and the side surface can be concave.

[0085] The height of the side wall surface 231-2 of the left cup part 231 measured based on the bottom surface 231-1 of the left cup part 231 may be the same in the central region 234 and both end regions 235. This will be described in detail as follows.

[0086] 10, the height of the side wall surface 231-2 of the left cup part 231 measured based on the bottom surface 231-1 of the left cup part 231 in the central region 234 may be y1. Then, referring to FIG. 11, the height of the side wall surface 231-2 of the left cup part 231 measured based on the bottom surface 231-1 of the left cup part 231 in the both end regions 235 may be y2. In this case, y1 and y2 may have the same value (y1=y2).

[0087] In the secondary battery pouch 230 manufactured by the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the height of the side wall surface of the right cup portion 232, measured based on the bottom surface 232-1 of the right cup portion 232, may be the same in the central region 234 and the both end regions 235. This will be described in detail as follows.

[0088] 10, the height of the sidewall of the right cup part 232 measured based on the bottom surface 232-1 of the right cup part 232 in the central region 234 may be y3. Then, referring to FIG. 11, the height of the sidewall of the right cup part 232 measured based on the bottom surface 232-1 of the right cup part 232 in the both end regions 235 may be y4. In this case, y3 and y4 may have the same value (y3=y4).

[0089] In the secondary battery pouch 230 manufactured by the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the left cup portion 231 and the right cup portion 232 may be formed to have shapes that are symmetrical to each other with respect to the pouch bridge portion 240. Specifically, being symmetrical to each other with respect to the pouch bridge portion 240 may mean that the left cup portion 231 and the right cup portion 232 have shapes that are symmetrical to each other with respect to an imaginary plane that cuts the pouch bridge portion 240 vertically.

[0090] In this case, y1 = y3 and y2 = y4 may be true. As mentioned above, y1 = y2 and y3 = y4, so that y1 = y2 = y3 = y4 can be true. That is, y1, y2, y3, and y4 can all have the same value.

[0091] When manufactured using the secondary battery pouch forming apparatus 200 according to the second embodiment of the present invention, the secondary battery pouch 230 of the present invention can be formed such that the left cup portion 231 and the right cup portion 232 have horizontal bottom surfaces in the central region 234 and inclined bottom surfaces in both end regions 235. This allows the pouch bridge portion 240 to stretch significantly when the pouch is folded.

[0092] In the secondary battery pouch 230 of the present invention, the bottom surface is formed to be inclined at both end regions 235, so that when the pouch is folded in half so that the edge of the left cup portion 231 and the edge of the right cup portion 232 contact each other, the bottom portions of both end regions 235 move more. This results in the corner portions of both end regions 235 pulling the central region 234 of the pouch more. As a result, the pouch bridge portion 240 can stretch significantly more at the central region 234.

[0093] If the pouch bridge portion 240 is significantly stretchable, it can move further outward (E) and extend in a straight line compared to the state shown in Fig. 1. This prevents it from interfering with the electrode assembly, thereby preventing damage to the electrode assembly.

[0094] In addition to preventing damage to the electrode assembly and the resulting damage to the cells, the secondary battery pouch forming apparatus 200 and secondary battery according to the second embodiment of the present invention can also achieve the effects of improving cell positioning accuracy and preventing wrinkles from forming in the cell seal portion.

[0095] When the pouch bridge portion 240 is stretchable, the appearance of the cell is precisely formed, allowing for precise position measurement using a vision camera, etc. This improves positional accuracy. In addition, when the pouch bridge portion 240 is stretchable, the improved accuracy also prevents wrinkles from occurring when sealing the periphery of the pouch.

[0096] As a result, the secondary battery pouch forming apparatus 200 and secondary battery according to the second embodiment of the present invention can realize a secondary battery of excellent quality.

[0097] Third embodiment FIG. 12 is a perspective view showing a die of a secondary battery pouch forming apparatus according to a third embodiment of the present invention.

[0098] The third embodiment of the present invention differs from the first and second embodiments in that it is a secondary battery pouch forming apparatus and a secondary battery pouch manufactured by the apparatus that combines the features of the first and second embodiments described above.

[0099] The second embodiment will be described focusing on the differences and omitting as much as possible the content common to the first and second embodiments. In other words, if content not explained in the third embodiment is necessary, it is clear that it can be regarded as the content of the first and second embodiments.

[0100] The secondary battery pouch forming apparatus 300 according to the third embodiment of the present invention can include a die 310 and a punch.

[0101] The die 310 may have a base surface 313 on which the pouch is placed, and a receiving groove for forming the cup portion of the pouch formed on the base surface 313.

[0102] Specifically, the die 310 includes a left-side storage groove portion 311 having a concave shape, a right-side storage groove portion 312 formed on the side of the left-side storage groove portion 311 and having a concave shape, and a bridge portion 320 connecting the left-side storage groove portion 311 and the right-side storage groove portion 312 between the left-side storage groove portion 311 and the right-side storage groove portion 312.

[0103] The punch may be configured to be inserted into the receiving groove of the die 310 and form the cup portion of the pouch. The punch has a shape corresponding to the groove portion of the die 310, and can be inserted into the concave groove portion of the die 310 to form the pouch.

[0104] 12, in the secondary battery pouch forming apparatus 300 according to the third embodiment of the present invention, the bridge portion 320 may be formed in a concave shape such that the height of the central portion 321 in the length direction (L) is lower than the height of both end portions 322. Here, the height of the bridge portion 320 may continuously decrease from both end portions 322 to the central portion 321.

[0105] The cross section of bridge portion 320 taken along line G-G' shown in Fig. 12 may have the same shape as that shown in Fig. 3. Therefore, the contents explained in the above description of the first embodiment based on Fig. 3 can be similarly applied to secondary battery pouch forming apparatus 300 of the third embodiment.

[0106] The cross section of the bridge portion 320 may be formed in a shape such as a partial or complete U-shape, or a partial or complete circle or oval shape. The height (h1) of the center portion 321 of the bridge portion 320 may be 9 mm to 10 mm, and the heights (h2) of both end portions 322 of the bridge portion 320 may be 11 mm to 12 mm.

[0107] Also, referring to Figure 12, in the secondary battery pouch forming apparatus 300 of the third embodiment of the present invention, the left side storage groove portion 311 and the right side storage groove portion 312 have bottom surfaces formed horizontally in the central region 314 and inclined in the both end regions 315, based on a direction parallel to the longitudinal direction (L) of the bridge portion 320.

[0108] The cross section of the bottom surface of the accommodating groove taken along R1 shown in Fig. 12 may have the same shape as that shown in Fig. 7, and the cross section of the bottom surface of the accommodating groove taken along R2 and R3 may have the same shape as that shown in Fig. 8. Therefore, the contents explained in the second embodiment above based on Figs. 7 and 8 can be similarly applied to the secondary battery pouch forming apparatus 300 of the third embodiment.

[0109] In both end regions 315, the bottom surfaces of the left and right accommodating grooves 311, 312 may be inclined so that the height increases as they approach the bridge portion 320, and the inclination angle (θ) between the bottom surfaces of the left and right accommodating grooves 311, 312 and the horizontal plane may be 1 to 10 degrees.

[0110] Each of the left and right storage grooves 311 and 315 includes a bottom surface and a side wall surface extending upward from the periphery of the bottom surface, and the height of the side wall surface of the left storage groove 311 measured based on the bottom surface of the left storage groove 311 may be the same in the central region 314 and the end regions 315.

[0111] In addition, the height of the sidewall surface of the right accommodating groove 312 measured based on the bottom surface of the right accommodating groove 312 may be the same in the central region 314 and the end regions 315. The left accommodating groove 311 and the right accommodating groove 312 may be formed symmetrically with respect to each other with the bridge portion 320 at the center.

[0112] The secondary battery pouch manufactured by the secondary battery pouch forming apparatus 300 according to the third embodiment of the present invention can also have the features of the secondary battery pouches manufactured in the first and second embodiments.

[0113] A secondary battery pouch (not shown) manufactured by the secondary battery pouch forming apparatus 300 according to the third embodiment of the present invention can include a pouch cup portion and a pouch bridge portion.

[0114] The pouch bridge portion is formed concavely so that the height of the central portion is lower than the height of both end portions based on the longitudinal direction, and the left cup portion and the right cup portion have bottom surfaces formed horizontally in the central region and inclined in the both end regions based on a direction parallel to the longitudinal direction of the pouch bridge portion.

[0115] Furthermore, since the secondary battery pouch manufactured by the secondary battery pouch forming apparatus 300 according to the third embodiment of the present invention combines the features of the secondary battery pouches manufactured in the first and second embodiments, the features of the secondary battery pouch described in the first embodiment above based on Figure 5 and the features of the secondary battery pouch described in the second embodiment above based on Figures 9 to 11 can be applied directly to the secondary battery pouch manufactured by the secondary battery pouch forming apparatus 300 according to the third embodiment.

[0116] Therefore, the secondary battery pouch forming apparatus 300 according to the third embodiment and the secondary battery pouch manufactured thereby allow the pouch bridge portion to stretch well when the pouch is folded, thereby preventing damage to the cells, improving cell positioning accuracy, and preventing wrinkles from forming in the cell seal portion, thereby enabling the realization of a secondary battery of excellent quality.

[0117] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope equivalent to the technical concept of the present invention and the claims that will be described later by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0118] 100, 200, 300: Secondary battery pouch molding equipment 110, 210, 310: Die 111, 211, 311: Left side storage groove 211-1: Bottom of left storage groove 211-2: Side wall 112, 212, 312: Right side storage groove 212-1: Bottom of the right-side storage groove 113, 213, 313: Base surface 214, 314: Central area 215, 315: Both end regions 120, 220, 320: Bridge section 121, 321: Central part 122, 322: Both ends 130, 230: Secondary battery pouch 131, 231: Left cup part 231-1: Bottom of the left cup 231-2: Side wall 232-1: Bottom of the right cup 132, 232: Right cup part 133, 233: Pouch cup part 234: Central area of pouch 235: Pouch end regions 140, 240: Pouch bridge section 141: Central part 142: Both ends 150: Punch 151: Punch protrusion

Claims

1. a die having a base surface on which the pouch is placed and a receiving groove for forming a cup portion of the pouch formed thereon; a punch inserted into the receiving groove of the die to form a cup portion of the pouch; Including, The die is a left storage groove portion having a concave shape; a right-side receiving groove portion formed on a side of the left-side receiving groove portion and having a concave shape; a bridge portion between the left accommodating groove portion and the right accommodating groove portion, the bridge portion connecting the left accommodating groove portion and the right accommodating groove portion; Including, The bridge portion is formed in a concave shape so that the height of the central portion is lower than the height of both end portions in the longitudinal direction.

2. The secondary battery pouch forming device according to claim 1 , wherein the bridge portion has a height that continuously decreases from the both end portions to the center portion.

3. 2. The secondary battery pouch forming device according to claim 1, wherein a cross section of the bridge portion cut along an imaginary vertical plane that passes through the bridge portion and separates the left-side accommodating groove portion from the right-side accommodating groove portion is formed into a shape that resembles part or all of a U-shape.

4. 2. The secondary battery pouch forming device according to claim 1, wherein a cross section of the bridge portion cut along an imaginary vertical plane that passes through the bridge portion and separates the left accommodating groove portion from the right accommodating groove portion is formed into a shape that is a part or all of a circle or an ellipse.

5. The height (h1) of the center portion of the bridge portion is 9 mm to 10 mm, 2. The secondary battery pouch forming device according to claim 1, wherein the height (h2) of each of the two end portions of the bridge portion is 11 mm to 12 mm.

6. The secondary battery pouch forming device according to any one of claims 1 to 5, wherein the punch includes a punch protrusion having a shape that protrudes to correspond to the recess of the bridge portion.

7. a die having a base surface on which the pouch is placed and a receiving groove for forming a cup portion of the pouch formed thereon; a punch inserted into the receiving groove of the die to form a cup portion of the pouch; Including, The die is a left storage groove portion having a concave shape; a right-side receiving groove portion formed on a side of the left-side receiving groove portion and having a concave shape; a bridge portion between the left accommodating groove portion and the right accommodating groove portion, the bridge portion connecting the left accommodating groove portion and the right accommodating groove portion; Including, the left-side accommodating groove portion and the right-side accommodating groove portion have bottom surfaces that are horizontal in the central region and inclined in the end region, based on a direction parallel to the longitudinal direction of the bridge portion.

8. In the end regions, The secondary battery pouch forming device according to claim 7 , wherein bottom surfaces of the left and right accommodating grooves are formed to be inclined so that their heights increase as they approach the bridge portion.

9. In the end regions, 8. The secondary battery pouch forming device according to claim 7, wherein the inclination angle (θ) formed by the bottom surfaces of the left and right accommodating grooves with respect to the horizontal plane is 1 to 10 degrees.

10. Each of the left and right accommodating grooves includes a bottom surface and a side wall surface extending upward from a peripheral edge of the bottom surface, 8. The secondary battery pouch forming device according to claim 7, wherein the height of the side wall surface of the left side accommodating groove portion measured based on the bottom surface of the left side accommodating groove portion is the same in the central region and the both end regions (t1 = t2).

11. 11. The secondary battery pouch forming device according to claim 10, wherein the height of the side wall surface of the right side accommodating groove portion measured based on the bottom surface of the right side accommodating groove portion is the same in the central region and the both end regions (t3 = t4).

12. The secondary battery pouch forming device according to any one of claims 7 to 11, wherein the left accommodating groove portion and the right accommodating groove portion are formed in shapes symmetrical to each other with the bridge portion as the center.

13. a die having a base surface on which the pouch is placed and a receiving groove for forming a cup portion of the pouch formed thereon; a punch inserted into the receiving groove of the die to form a cup portion of the pouch; Including, The die is a left storage groove portion having a concave shape; a right-side receiving groove portion formed on a side of the left-side receiving groove portion and having a concave shape; a bridge portion between the left accommodating groove portion and the right accommodating groove portion, the bridge portion connecting the left accommodating groove portion and the right accommodating groove portion; Including, The bridge portion is formed in a concave shape such that the height of the center portion is lower than the height of both end portions in the length direction, the left-side accommodating groove portion and the right-side accommodating groove portion have bottom surfaces that are horizontal in the central region and inclined in the end region, based on a direction parallel to the longitudinal direction of the bridge portion.

14. a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed; a pouch bridge portion between the left cup portion and the right cup portion, connecting the two cup portions; Including, The pouch bridge portion is formed in a concave shape such that the height of the center portion is lower than the height of both end portions in the length direction (L').

15. The height of the central portion of the pouch bridge portion is 2 mm to 4 mm, The secondary battery pouch according to claim 14, wherein the height of the both ends of the pouch bridge portion is 4 mm to 6 mm.

16. a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed; a pouch bridge portion between the left cup portion and the right cup portion, connecting the two cup portions; Including, A secondary battery pouch in which the left cup portion and the right cup portion have bottom surfaces that are horizontal in the central region and inclined in the end regions, based on a direction parallel to the longitudinal direction of the pouch bridge portion.

17. a pouch cup portion in which two cup portions, a left cup portion and a right cup portion, are formed; a pouch bridge portion between the left cup portion and the right cup portion, connecting the two cup portions; Including, The pouch bridge portion is formed in a concave shape such that the height of the center portion is lower than the height of both end portions in the length direction, A secondary battery pouch in which the left cup portion and the right cup portion have bottom surfaces that are horizontal in the central region and inclined in the end regions, based on a direction parallel to the longitudinal direction of the pouch bridge portion.

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