Pouch manufacturing equipment

Abstract

The present invention relates to a pouch manufacturing apparatus, and may include a lower die including a forming area formed by indenting inward to form a cup portion in a pouch film and a support area formed flat outside the forming area, a punch configured to press the pouch film placed on the lower die toward the forming area, a stripper configured to press the pouch film toward the support area to support the pouch film while being pressed by the punch, and a local pressure unit configured to press the first area of ​​the pouch film pressed by the stripper more strongly than the second area.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0043649, filed April 3, 2023, and Korean Patent Application No. 10-2024-0044116, filed April 1, 2024, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a pouch manufacturing apparatus. [Background technology]

[0003] In general, secondary batteries refer to batteries that can be charged and discharged, unlike primary batteries that cannot be recharged, and are widely used in electronic devices such as mobile phones, laptops, and camcorders, as well as electric vehicles, etc. In particular, lithium secondary batteries have a larger capacity and higher energy density than nickel-cadmium batteries or nickel-metal hydride batteries, and therefore their use is rapidly increasing.

[0004] Depending on the shape of the battery case, secondary batteries can be classified into cylindrical or prismatic batteries in which an electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries in which an electrode assembly is housed in a pouch-type case made of a laminate sheet.

[0005] FIG. 1 is a diagram illustrating an example of a pouch-type secondary battery. The pouch-type secondary battery 1 (pouch-type cell) includes an electrode assembly 2 formed by stacking electrodes and separators, and a pouch-type exterior material 20 that houses the electrode assembly 2. Electrode tabs 15 may be connected to the electrodes of the electrode assembly 2. The electrode tabs 15 may be welded to each other in predetermined areas and then connected to an electrode lead 17 by welding. The exterior material 20 includes a receiving portion 21 (cup portion) for housing the electrode assembly 2. The receiving portion 21 of the exterior material 20 may be formed into one or two indented portions. FIG. 1 illustrates an example of the receiving portion 21 formed into two indented portions. Such an exterior material 20 may be manufactured by molding a pouch film. A sealing portion 23 (terrace) is formed around the periphery of the receiving portion 21 by sealing.

[0006] Meanwhile, the pouch-shaped outer packaging material 20 may be manufactured by partially compressing a pouch film. For example, pressing a certain portion of the pouch film with a punch may form the containing portion 21 in the pouch film. During this pressing, another portion of the pouch film is typically pressed and fixed with a stripper. However, a stripper typically applies uniform pressure to the pouch film. Such uniform pressure is likely to cause wrinkles around the portion of the pouch film pressed by the punch. Recently, consideration has been given to using a stainless steel layer as the metal layer of the pouch film. However, metals such as stainless steel have a relatively high rigidity, and thus, if the forming process is carried out as described above, wrinkles and the like are very likely to occur in the pouch film during forming. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a pouch manufacturing apparatus that can reduce or prevent the occurrence of cracks and wrinkles in a pouch film during the formation of the pouch film. [Means for solving the problem]

[0008] As an example, a pouch manufacturing apparatus may include a lower die including a forming area formed by indenting inward to form a cup portion in a pouch film and a support area formed flat outside the forming area, a punch configured to press the pouch film placed on the lower die toward the forming area, a stripper configured to press the pouch film toward the support area to support the pouch film while being pressed by the punch, and a local pressure unit configured to press the first area of ​​the pouch film pressed by the stripper more strongly than the second area.

[0009] As another example, the local pressure applying portion may include a protrusion provided in one of the support areas facing the stripper, the stripper, and the stripper, and a recess provided in the other of the support areas facing the stripper, corresponding to the protrusion.

[0010] In another example, the protrusion may be formed to protrude toward the recess, and the recess may be formed to be recessed to accommodate the protrusion.

[0011] In another example, the protrusion may include a long-side parallel protrusion arranged parallel to the long side of the frame of the forming area, and a short-side parallel protrusion arranged parallel to the short side extending perpendicularly from the long side of the frame of the forming area.

[0012] In another example, an end of the long-side parallel protrusion may further protrude outward from an end of the long side of the frame of the forming region along an extension direction of the long-side parallel protrusion.

[0013] In another example, an end of the short-side parallel protrusion may further protrude outward from an end of the short side of the frame of the forming region along an extension direction of the short-side parallel protrusion.

[0014] In another example, the end of the long-side parallel protrusion may be located adjacent to the end of the short-side parallel protrusion, but may not be connected to the short-side parallel protrusion.

[0015] In another example, the protrusion may further include a long-side inclined protrusion extending from an end of the long-side parallel protrusion at an incline with respect to the long-side parallel protrusion.

[0016] In another example, the protrusion may further include a short-side inclined protrusion extending from an end of the short-side parallel protrusion at an incline with respect to the short-side parallel protrusion.

[0017] In another example, the protrusions may further include guide protrusions extending across between the ends of the long-side parallel protrusions and the short-side parallel protrusions.

[0018] In another example, the protrusions may further include guide protrusions extending in a direction to interpose between ends of the long-side parallel protrusions and ends of the short-side parallel protrusions.

[0019] In another example, the height of the protrusion may be equal to or greater than 0.5 mm and less than 2 mm.

[0020] In another example, the protrusion may have a horizontal portion formed horizontally and spaced apart above the support area, a curved portion having a curved shape extending from one end of the horizontal portion, and a vertical portion extending from one end of the curved portion that is not connected to the horizontal portion toward the support area.

[0021] In another example, the stripper may include a stripper body having a pressing surface configured to pressurize the pouch film and forming the outer shape of the stripper, a horizontally formed ceiling inner wall formed inside the stripper body, a vertical inner wall formed inside the stripper body and vertically upward from the pressing surface, and defining the recessed portion together with the ceiling inner wall, and a curved connecting portion connecting a lower end of the vertical inner wall to the pressing surface.

[0022] In another example, the local pressure applying portion may include a protruding plate arranged on the support area, and a cover that covers at least a portion of the support area above the support area with the protruding plate arranged inside, and the cover may be partially protruded toward the stripper by the protruding plate arranged inside.

[0023] In yet another example, the pouch film can include a metal layer of stainless steel. [Effects of the Invention]

[0024] According to the present invention, by applying strong local pressure to the pouch film via the local pressure unit, it is possible to reduce or prevent the occurrence of cracks and wrinkles in the pouch film during the formation of the pouch film. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram illustrating an example of a pouch-type secondary battery. [Figure 2] 1 is a perspective view illustrating a pouch manufacturing apparatus according to a first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of the pouch manufacturing apparatus of FIG. 2. [Figure 4] FIG. 3 is a plan view of the lower die of FIG. 2 as viewed from above. [Figure 5] FIG. 3 is a perspective view of a pouch film formed by the pouch manufacturing apparatus of FIG. 2. [Figure 6] 3 is a plan view illustrating a first modified example of the protrusion of FIG. 2. FIG. [Figure 7] 3 is a plan view illustrating a second modification of the protrusion of FIG. 2. FIG. [Figure 8] 3 is a plan view illustrating a third modified example of the protrusion of FIG. 2. FIG. [Figure 9] 2. FIG. 6 is a plan view illustrating a fourth modified example of the protrusion of FIG. [Figure 10] 4 is an enlarged cross-sectional view of the local pressure applying portion of FIG. 3. FIG. [Figure 11] FIG. 4 is a cross-sectional view illustrating a pouch manufacturing apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] 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 present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0027] 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 when adding reference symbols to components in each drawing in this specification, the same or similar reference symbols will be used for the same or similar components throughout the specification.

[0028] Furthermore, the terms and words used in this specification and claims should not be interpreted in a way that is limited to their ordinary and 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 an inventor can appropriately define the concept of a term in order to best explain his or her invention.

[0029] Embodiment 1 Fig. 2 is a perspective view illustrating a pouch manufacturing apparatus according to a first embodiment of the present invention, and Fig. 3 is a cross-sectional view of the pouch manufacturing apparatus of Fig. 2. As shown in Figs. 2 and 3, the pouch manufacturing apparatus according to the first embodiment of the present invention may include a lower die 110, a punch 130, and a stripper 150. For reference, the contents of the first embodiment may be equally applied to the following embodiments unless they are mutually contradictory.

[0030] Basic structure of pouch manufacturing equipment The lower die 110 may include a forming region 111 formed by indenting inward to form a cup portion 21 (see FIG. 5) in the pouch film F (see FIG. 3). The forming region 111 may be a groove or hole formed by indenting downward from an upper surface 117 of a lower die body 115 that forms the outer shape of the lower die 110. The lower die 110 may include a support region 113 formed generally flat outside the forming region 111. The support region 113 may be all or a part of the upper surface 117 of the lower die body 115 that surrounds the forming region 111.

[0031] The punch 130 may be a block provided to pressurize the pouch film F placed on the lower die 110 toward the forming region 111. This pressure may form a cup portion 21 in the pouch film F. The punch 130 may be supported by an upper die 120 disposed spaced apart above the lower die 110. A connecting pillar B may be provided between the upper die 120 and the lower die 110 to maintain the spacing. Cylinders 171 and 176 may be provided in the upper die 120 for vertical movement of the punch 130 and the stripper 150, which will be described later.

[0032] The punch 130 may be provided so as to move toward the forming region 111 while being supported by the upper die 120. For example, the punch 130 may be indirectly fixed to the upper die 120 by being connected to a punch cylinder 171 fixed to the upper die 120, but may be moved vertically relative to the upper die 120 by operation of the punch cylinder 171. The punch cylinder 171 may include a cylinder body 172 and a cylinder rod 173 that reciprocates due to fluid pressure supplied to the inside of the cylinder body 172. The punch 130 may be connected to the cylinder rod 173 of the punch cylinder 171.

[0033] The stripper 150 supports the pouch film F during pressure application by the punch 130 and may be configured to press the pouch film F placed on the lower die 110 toward the support region 113 of the lower die 110. The stripper 150 can secure the pouch film F by applying pressure. The stripper 150 may be connected to a stripper cylinder 176 fixed to the upper die 120 and indirectly fixed to the upper die 120. The stripper 150 may be moved vertically relative to the upper die 120 by operation of the stripper cylinder 176. The stripper cylinder 176 may include a cylinder body 177 and a cylinder rod 178 that reciprocates due to fluid pressure supplied to the interior of the cylinder body 177. The stripper 150 may be connected to the cylinder rod 178. FIG. 2 illustrates an example of a stripper 150 configured in the shape of a picture frame that is generally rectangular and has a rectangular hole H (see FIG. 3) therein. The punch 130 can move up and down through the stripper 150 via a hole H formed in the center of the stripper 150 .

[0034] The process of forming a pouch film F using the pouch manufacturing apparatus of this embodiment will be described below with reference to Figure 3. With the pouch film F placed on the lower die 110, the stripper 150 is lowered by the stripper cylinder 176. The stripper 150 applies pressure to the pouch film F placed in the support region 113 of the lower die 110 to fix the pouch film F during formation. Next, the punch 130 is lowered by the punch cylinder 171. This applies pressure to the pouch film F to form the cup portion 21 (see Figure 5). Next, the punch 130 is raised by the punch cylinder 171.

[0035] Local pressure unit of pouch manufacturing equipment As shown in Figures 2 and 3, the pouch manufacturing apparatus according to the first embodiment of the present invention may include a local pressure unit 190. The local pressure unit 190 may apply a stronger pressure to the first region F1 of the pouch film F, which is pressed by the stripper 150, than to the second region F2 (see Figure 3). The first region F1 may be a portion of the pouch film F located between the stripper 150 and the support region 113 of the lower die 110. The second region F2 may be another portion of the pouch film F located between the stripper 150 and the support region 113 of the lower die 110. For example, when the portion of the pouch film F located between the stripper 150 and the support region 113 is divided into two or more regions, one of these regions may be the first region F1 and the other may be the second region F2. 3 illustrates an example in which a portion corresponding to a protrusion 191 (described later) is a first region F1, and the remaining portion is a second region F2. The local pressure applying unit 190 can apply a stronger pressure to a portion (the first region) of the portion of the pouch film F located between the stripper 150 and the support region 113 (for example, the first region and the second region).

[0036] The local pressure unit 190 can reduce or prevent cracks and wrinkles from occurring in the pouch film F during forming through such local pressure. Without the local pressure unit 190, the portion of the pouch film F located between the stripper 150 and the support region 113 would be uniformly pressed by the stripper 150 during forming. However, such uniform pressure is likely to cause wrinkles and the like around the portion of the pouch film F that is pressed by the punch 130. However, when the local pressure unit 190 is provided, a portion (first region) of the portion of the pouch film F located between the stripper 150 and the support region 113 is pressed more strongly, which can result in relatively few wrinkles and the like occurring.

[0037] The local pressure portion 190 may include the stripper 150 and a protrusion 191 provided in one of the support regions 113 facing the stripper 150. The local pressure portion 190 may include the stripper 150 and a depression 193 provided in the other of the support regions 113 facing the stripper 150. Illustrated in Figures 2 and 3 are the depression 193 formed in the stripper 150 and the protrusion 191 formed in the support region 113.

[0038] The protrusion 191 may be formed to correspond to the depression 193. Here, the correspondence may be a correspondence in position rather than a correspondence in shape. For example, the protrusion 191 may have a semicircular cross section, while the depression 193 may have a rectangular cross section. However, the protrusion 191 and the depression 193 may be formed at positions where they meet when the stripper 150 and the support region 113 are adjacent to each other as the stripper 150 moves.

[0039] The protrusion 191 may be formed to protrude toward the recess 193. The recess 193 may be formed to be recessed to accommodate the protrusion 191. When the stripper 150 and the support region 113 are adjacent to each other due to the movement of the stripper 150, the protrusion 191 may be inserted into the recess 193.

[0040] When the protrusion 191 and the depression 193 are formed, the portion of the pouch film F that is pressurized by the protrusion 191 (e.g., the first region) may be pressurized more strongly by the opposing surfaces of the stripper 150 and the support region 113 than the portion that is pressurized without the protrusion 191 (e.g., the second region).

[0041] 4, the protrusion 191 may include a long-side parallel protrusion 191L ​​arranged parallel to the long side L of the frame of the forming region 111, and a short-side parallel protrusion 191S arranged parallel to the short side S extending perpendicular to the long side L of the frame of the forming region 111. FIG. 4 is a plan view of the lower die 110 of FIG. 2 viewed from above. The depression 193 may also include a long-side parallel depression 193L (see FIG. 2) corresponding to the long-side parallel protrusion 191L, and a short-side parallel depression 193S (see FIG. 2) corresponding to the short-side parallel protrusion 191S.

[0042] With this configuration, the protrusions 191 and the depressions 193 can be arranged to at least partially surround the portion of the pouch film F that is pressed by the punch 130, further suppressing the occurrence of wrinkles and the like. To completely surround the portion of the pouch film F that is pressed by the punch 130, a pair of long-side parallel protrusions 191L ​​and a pair of short-side parallel protrusions 191S may be provided, as shown in FIG. 4 . This also applies to the long-side parallel depressions 193L and the short-side parallel depressions 193S. For reference, when the forming region 111 is formed to have a rectangular cross section, the long side L of the forming region 111 may be longer than the short side S of the forming region 111. However, when the forming region 111 is formed to have a square cross section, the long side L and the short side S of the forming region 111 in this specification may be sides of the same length.

[0043] Meanwhile, the end of the long side parallel protrusion 191L ​​may be formed to protrude further outward from the end of the long side L of the frame of the forming region 111 in the extension direction of the long side parallel protrusion 191L ​​(see A1 in FIG. 4). Both ends of the long side parallel protrusion 191L ​​may all be formed to protrude further outward from both ends of the long side L of the frame of the forming region 111. The long side parallel recess 193L may also be formed to correspond to the long side parallel protrusion 191L. The end of the short side parallel protrusion 191S may also be formed to protrude further outward from the end of the short side S of the frame of the forming region 111 in the extension direction of the short side parallel protrusion 191S (see A2 in FIG. 4). Both ends of the short side parallel protrusion 191S may all be formed to protrude further outward from both ends of the short side S of the frame of the forming region 111. The short-side parallel recesses 193S may also be formed to correspond to the short-side parallel protrusions 191S.

[0044] The end of the long side parallel protrusion 191L ​​is located adjacent to the end of the short side parallel protrusion 191S, but it does not have to be connected to the short side parallel protrusion 191S. A long side parallel recess 193L and a short side parallel recess 193S may be formed correspondingly. Arranging the long side parallel protrusion 191L ​​and the short side parallel protrusion 191S to almost entirely surround the forming region 111 of the lower die 110 can be effective in suppressing wrinkles. However, if the long side parallel protrusion 191L ​​and the short side parallel protrusion 191S entirely surround the forming region 111, wrinkles may be induced around the apex formed by the meeting of the long side parallel protrusion 191L ​​and the short side parallel protrusion 191S.

[0045] When a pouch film F is formed using the manufacturing apparatus of this embodiment, a pouch film having the shape shown in FIG. 5 can be obtained. FIG. 5 is a perspective view of a pouch film formed by the pouch manufacturing apparatus of FIG. 2. When a certain portion of the pouch film F is pressed by a punch 130, a cup portion 21 can be formed. When another portion of the pouch film F is pressed by a protrusion 191, a groove portion 30 can be formed. After preparing two pouch films as shown in FIG. 5, a pouch battery can be obtained by joining the two pouch films together with an electrode assembly interposed therebetween. The portion where the groove portion 30 is formed can be cut during the manufacturing process of the pouch battery.

[0046] Meanwhile, as shown in FIG. 6, the protrusion 191 may further include a long-side inclined protrusion 191I1 extending from an end of the long-side parallel protrusion 191L ​​at an incline relative to the long-side parallel protrusion 191L. As shown in FIG. 6, the protrusion 191 may further include a short-side inclined protrusion 191I2 extending from an end of the short-side parallel protrusion 191S at an incline relative to the short-side parallel protrusion 191S. FIG. 6 is a plan view illustrating a first modified example of the protrusion in FIG. 2. The long-side inclined protrusion 191I1 may be disposed at each end of the long-side parallel protrusion 191L. The short-side inclined protrusion 191I2 may also be disposed at each end of the short-side parallel protrusion 191S. The inclined protrusions 191I1 and 191I2 do not have to be connected to each other. The inclined protrusions 191I1 and 191I2 may extend at an angle at each end in a direction away from the apex formed at the meeting of the long side L and short side S of the frame of the forming area 111. The inclined protrusions 191I1 and 191I2 can guide the flow of the pouch film F (see FIG. 3) that may occur near the apex during the formation of the pouch film F, and the resulting improvement in fluidity can further suppress the occurrence of wrinkles near the apex.

[0047] The protrusion 191 of FIG. 2 may be modified as shown in FIG. 7. FIG. 7 is a plan view illustrating a second modification of the protrusion of FIG. 2. The protrusion 191' of FIG. 7 may include a long-side parallel protrusion 191L' and a short-side parallel protrusion 191S'. The protrusion 191' may further include a long-side inclined protrusion 191I1' extending at an end of the long-side parallel protrusion 191L' and inclined relative to the long-side parallel protrusion 191L'. The protrusion 191' may further include a short-side inclined protrusion 191I2' extending at an end of the short-side parallel protrusion 191S' and inclined relative to the short-side parallel protrusion 191S'. Unlike the inclined protrusions 191I1 and 191I2 of FIG. 6, the inclined protrusions 191I1' and 191I2' of FIG. 7 may extend at an inclination at each end in a direction approaching the apex between the long side L and the short side S. For example, the inclined protrusions 191I1' and 191I2' in Fig. 7 may be extended so as to face each other at their ends. The inclined protrusions 191I1' and 191I2' in Fig. 7 can also further prevent wrinkles from occurring near the apex.

[0048] The protrusion 191 of FIG. 2 may be modified as shown in FIG. 8. FIG. 8 is a plan view illustrating a third modification of the protrusion of FIG. 2. The protrusion 191″ of FIG. 8 may include a long-side parallel protrusion 191L″ and a short-side parallel protrusion 191S″. The protrusion 191″ may further include a guide protrusion 191G″ extending across between the end of the long-side parallel protrusion 191L″ and the end of the short-side parallel protrusion 191S″. For example, the guide protrusion 191G″ may extend in a direction connecting the vertex formed at the intersection of the extension line of the long-side parallel protrusion 191L″ and the extension line of the short-side parallel protrusion 191S″ to the vertex formed at the intersection of the long side L and the short side S of the forming region 111. FIG. 8 exemplarily illustrates four guide protrusions 191G″ provided corresponding to the four vertices of the forming region 111. The guide protrusion 191G'' can guide the flow of the pouch film F that may occur near the apex of the forming area 111 during the formation of the pouch film F, and the resulting improved fluidity can further suppress the occurrence of wrinkles near the apex.

[0049] The protrusion 191 of FIG. 2 may be modified as shown in FIG. 9. FIG. 9 is a plan view illustrating a fourth modification of the protrusion of FIG. 2. The protrusion 191''' of FIG. 9 may include a long-side parallel protrusion 191L''' and a short-side parallel protrusion 191S'''. The protrusion 191''' may further include a guide protrusion 191G''' extending in a direction that intercepts the end of the long-side parallel protrusion 191L''' and the end of the short-side parallel protrusion 191S'''. For example, the guide protrusion 191G''' may extend in a direction that intersects a straight line connecting an apex formed at the intersection of an extension line of the long-side parallel protrusion 191L''' and an extension line of the short-side parallel protrusion 191S''' to an apex formed at the intersection of the long side L and the short side S of the forming region 111. The guide protrusion 191G''' may extend generally in a straight line connecting the end of the long-side parallel protrusion 191L''' and the end of the short-side parallel protrusion 191S'''. FIG. 9 exemplarily illustrates four guide protrusions 191G''' provided corresponding to the four vertices of the forming region 111. The guide protrusions 191G''' in FIG. 9 can also further suppress the occurrence of wrinkles near the vertices of the forming region 111.

[0050] Protrusions and depressions in locally pressurized areas The protrusions 191 and depressions 193 of the local pressure applying portion 190 will be described in detail with reference to Fig. 10. Fig. 10 is an enlarged cross-sectional view of the local pressure applying portion of Fig. 3 .

[0051] The protrusion 191 may include a horizontal portion 191H formed horizontally, a vertical portion 191V formed vertically, and a curved portion 191R connecting the horizontal portion 191H and the vertical portion 191V to each other. When the protrusion 191 is formed in the support region 113 of the lower die 110, the horizontal portion 191H may be spaced apart above the support region 113. The curved portion 191R may extend from one end of the horizontal portion 191H. The curved portion 191R may extend from both ends of the horizontal portion 191H. The vertical portion 191V may extend from the end of the curved portion 191R that is not connected to the horizontal portion 191H toward the support region 113.

[0052] When the protrusion 191 includes the curved surface portion 191R, the corners of the protrusion 191 are formed gently, which can prevent damage to the pouch film F during pressure application by the local pressure applying unit 190. For reference, the horizontal portion 191H, the vertical portion 191V, and the curved surface portion 191R of the protrusion 191 may each be one of many surfaces of the protrusion 191.

[0053] The recess 193 may be defined as a space surrounded by inner walls 193H and 193V formed inside the stripper body 151 that forms the outer shape of the stripper 150. More specifically, the stripper 150 may include the stripper body 151 that forms the outer shape of the stripper 150, a horizontally formed top inner wall 193H formed inside the stripper body 151, and a vertical inner wall 193V that is formed inside the stripper body 151 and vertically formed upward from the pressure surface 152 of the stripper body 151. The vertical inner wall 193V may define the recess 193 together with the top inner wall 193H.

[0054] The stripper 150 may include a curved connecting portion 193R that connects the lower end of the vertical inner wall 193V and the pressing surface 152. The gently curved connecting portion 193R can prevent damage to the pouch film F during pressure application by the local pressure unit 190. For reference, the pressing surface 152 of the stripper body 151 is a portion that is provided to pressurize the pouch film F and may be a part of the outer bottom surface of the stripper body 151.

[0055] On the other hand, the height H1 of the protrusion 191 (see FIG. 3), for example, the distance from the upper surface of the support region 113 to the horizontal portion 191H of the protrusion 191 (see FIG. 10), may be 0.5 mm or more and less than 2 mm. If the height of the protrusion 191 is less than 0.5 mm or 2 mm or more, it may not be possible to sufficiently prevent the occurrence of wrinkles.

[0056] Pouch Film F Structure Recently, there has been a demand for pouch-type batteries that can vent only at specific locations even at very high temperatures (e.g., 1,000°C).In conventional pouch-type batteries, sealing portion 23 (see FIG. 1) is generally formed by heat sealing between the resin layers (which can be made of polypropylene) of pouch film F. However, at very high temperatures, the resin layer melts, which can cause venting at unintended locations.

[0057] To solve this problem, it may be possible to form a sealing part by welding between metal layers with a very high melting point (e.g., stainless steel layers).When a sealing part is formed in this way, the sealing strength of the sealing part is very high, so the sealing part will not be destroyed even at very high temperatures.

[0058] The pouch manufacturing apparatus of this embodiment is suitable for manufacturing pouches using a pouch film F including a metal layer such as stainless steel. Metals such as stainless steel have relatively high rigidity, so when formed using existing manufacturing equipment, cracks and the like are very likely to occur in the pouch film F during molding. However, the pouch manufacturing apparatus of this embodiment can minimize the occurrence of cracks and the like even in such cases.

[0059] For reference, the pouch film F may include a metal layer including stainless steel, a first resin layer disposed inside the metal layer, and a second resin layer disposed outside the metal layer. The first resin layer may be a layer formed of polypropylene (PP). The first resin layer is required to have high insulating properties and corrosion resistance, and may be formed of another resin that meets these requirements. The first resin layer may not be provided in a portion where welding of the metal layer is required. The second resin layer may be a layer formed of polyethylene terephthalate (PET). The second resin layer is required to protect the secondary battery while electrically insulating it, and may be formed of another resin that meets these requirements. In the case of the pouch film F, only one of the first resin layer and the second resin layer may be provided, or neither of them may be provided.

[0060] Embodiment 2 11 is a cross-sectional view illustrating a pouch manufacturing apparatus according to a second embodiment of the present invention. As shown in FIG. 11, the pouch manufacturing apparatus according to this embodiment differs from the manufacturing apparatus of the first embodiment in the structure of the local pressure unit. For reference, the contents of the second embodiment may be equally applied to the above-mentioned embodiments unless they are mutually inconsistent.

[0061] The local pressure unit 190′ of this embodiment may include a protruding plate 196 disposed on the support region 113 of the lower die 110. The protruding plate 196 may be formed of an elastic material that is elastically deformed during pressure application by the stripper 150. The protruding plate 196 may be disposed in the same manner as the protruding portion 191 described above. For example, the protruding plate 196 may be disposed to surround a portion of the forming region 111, similar to the arrangement of the protruding portion 191 in FIG. 4. Alternatively, the protruding plate 196 may be disposed adjacent to the vertices formed by the intersection of the long side L (see FIG. 4) and the short side S of the forming region 111. In this case, a protruding plate 196 may be disposed at each of the four vertices.

[0062] The local pressure unit 190′ of this embodiment may include a cover 197 that covers at least a portion of the support area 113 above the support area 113 with the protruding plate 196 disposed therein. The cover 197 may partially protrude toward the stripper 150 due to the protruding plate 196 disposed therein. This protrusion may serve as the protrusion 191 described above. For reference, the cover 197 may be fixed to the lower die 110 by an adhesive, a fastening member, or the like.

[0063] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary skill in the art to which the present invention pertains without departing from the essential characteristics of the present invention.

[0064] Therefore, the embodiments disclosed in the present invention are intended to explain rather than limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0065] The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range thereof should be interpreted as being included in the scope of the present invention.

Claims

1. a lower die including a forming region formed to be indented inward for forming a cup portion in the pouch film, and a support region formed flat outside the forming region; a punch configured to press the pouch film disposed on the lower die toward the forming region; a stripper configured to press the pouch film toward the support area to support the pouch film during pressure application by the punch; and The pouch manufacturing apparatus includes a local pressure unit that applies a stronger pressure to the first region of the pouch film than to the second region of the pouch film that is applied with the stripper.

2. The local pressure applying unit is a protrusion provided on one of the stripper and the support area facing the stripper; and The pouch manufacturing apparatus according to claim 1 , further comprising a recessed portion provided in the stripper and in the other of the support regions facing the stripper, the recessed portion corresponding to the protrusion.

3. The protrusion is formed to protrude toward the recess, The pouch manufacturing apparatus according to claim 2 , wherein the recessed portion is formed to be recessed to accommodate the protrusion.

4. The protrusion is 3. The pouch manufacturing apparatus of claim 2, further comprising a long-side parallel protrusion arranged parallel to the long side of the frame of the forming area, and a short-side parallel protrusion arranged parallel to the short side of the frame of the forming area extending perpendicularly from the long side.

5. The end of the long side parallel protrusion is The pouch manufacturing apparatus according to claim 4 , wherein the long-side parallel protrusions further protrude outward from the ends of the long sides of the frame of the forming area along the extending direction of the long-side parallel protrusions.

6. The end of the short side parallel protrusion is The pouch manufacturing apparatus according to claim 4 , wherein the short-side parallel protrusions further protrude outward from the ends of the short sides of the frame of the forming area along the extension direction of the short-side parallel protrusions.

7. The end of the long side parallel protrusion is The pouch manufacturing apparatus according to claim 4 , wherein the short-side parallel protrusion is located adjacent to an end of the short-side parallel protrusion but is not connected to the short-side parallel protrusion.

8. The protrusion is The pouch manufacturing apparatus according to claim 4 , further comprising a long-side inclined protrusion extending at an end of the long-side parallel protrusion at an angle relative to the long-side parallel protrusion.

9. The protrusion is The pouch manufacturing apparatus according to claim 4 , further comprising a short-side inclined protrusion extending at an end of the short-side parallel protrusion at an angle relative to the short-side parallel protrusion.

10. The protrusion is The pouch manufacturing apparatus according to claim 7 , further comprising a guide protrusion extending across between an end of the long-side parallel protrusion and an end of the short-side parallel protrusion.

11. The protrusion is The pouch manufacturing apparatus according to claim 7 , further comprising a guide protrusion extending in a direction to block the gap between the end of the long-side parallel protrusion and the end of the short-side parallel protrusion.

12. The pouch manufacturing apparatus according to claim 2, wherein the height of the protrusion is equal to or greater than 0.5 mm and less than 2 mm.

13. The protrusion is a horizontal portion formed horizontally and spaced apart above the support region; a curved surface portion extending from one end of the horizontal portion; and The pouch manufacturing apparatus according to claim 2 , further comprising vertical portions extending from the ends of the curved portion, which are not connected to the horizontal portion, toward the support region.

14. The stripper is a stripper body having a pressure surface configured to apply pressure to the pouch film and defining the outer shape of the stripper; a horizontally formed inner ceiling wall formed inside the stripper body; a vertical inner wall formed inside the stripper body and extending vertically upward from the pressure surface, the vertical inner wall defining the recessed portion together with the ceiling inner wall; and The pouch manufacturing apparatus according to claim 2 , further comprising a curved connecting portion that connects a lower end of the vertical inner wall and the pressure surface.

15. The local pressure applying unit is a protruding plate disposed on the support area; and a cover that covers at least a part of the support area above the support area with the protruding plate disposed inside the cover; The pouch manufacturing apparatus according to claim 1 , wherein the cover is partially protruded toward the stripper by the protruding plate disposed inside the cover.

16. 16. The pouch manufacturing apparatus of claim 1, wherein the pouch film comprises a metal layer of stainless steel.

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