Pouch manufacturing device

Abstract

The present invention relates to a pouch manufacturing device. The pouch manufacturing device may include: a lower die including a forming area formed to be recessed inwardly in order to form a cup part on a pouch film, and a support area formed outside the forming area to be flat; a punch provided to press, toward the forming area, the pouch film to be disposed on the lower die; a stripper provided to press the pouch film toward the support area in order to support the pouch film while the pouch film is pressed by the punch; and a local pressing part for causing, among a first area and a second area of the pouch film which are pressed by the stripper, the first area to be more strongly pressed than the second area.

Description

Pouch manufacturing equipment

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0043649, filed April 3, 2023, and Korean Patent Application No. 10-2024-0044116, filed April 1, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a pouch manufacturing device.

[0005] Generally, secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. They are widely used in electronic devices such as mobile phones, laptops, and camcorders, as well as electric vehicles. In particular, lithium secondary batteries have a higher capacity than nickel-cadmium or nickel-hydrogen batteries and, due to their high energy density, are rapidly increasing in use.

[0006] Secondary batteries can be classified into cylindrical or square batteries in which the electrode assembly is built into a cylindrical or square metal can, and pouch-type batteries in which the electrode assembly is built into a pouch-type case of a laminate sheet, depending on the shape of the battery case.

[0007] Fig. 1 is a drawing 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 alternately stacking electrodes and separators, and a pouch-type outer case (20) in which the electrode assembly (2) is accommodated. Electrode tabs (15) may be connected to the electrodes of the electrode assembly (2), respectively. The electrode tabs (15) may be welded to each other in a predetermined region and then connected to an electrode lead (17) by welding. The outer case (20) includes a receiving portion (21; cup portion) for accommodating the electrode assembly (2). The receiving portion (21) of the outer case (20) may be formed by one or two concave-shaped portions. Fig. 1 illustrates an example of a receiving portion (21) formed by two concave-shaped portions. Such an outer case (20) may be manufactured by forming a pouch film. A sealing portion (23, terrace) is formed around the perimeter of the receiving portion (21) by sealing.

[0008] Meanwhile, the pouch-shaped outer packaging material (20) can be manufactured by partial pressurization of the pouch film. For example, by pressing a portion of the pouch film with a punch, a receiving portion (21) can be formed in the pouch film. During this pressurization, another portion of the pouch film is typically pressed and fixed with a stripper. However, the stripper typically presses the pouch film more or less uniformly. Such uniform pressurization can easily cause wrinkles, etc., around the portion of the pouch film that is pressed by the punch. Recently, the application of a stainless steel layer as the metal layer of the pouch film is being considered. However, metals such as stainless steel have relatively high rigidity, so if the forming is performed as described above, wrinkles, etc., are very likely to occur in the pouch film during the forming.

[0009] The object of the present invention is to provide a pouch manufacturing device capable of reducing or preventing cracks or wrinkles from occurring in a pouch film during forming of the pouch film.

[0010] In one example, a pouch manufacturing device may include a lower die including a forming region formed to be recessed inwardly for forming a cup portion in a pouch film, and a support region formed flatly on the outside of the forming region, a punch provided to press the pouch film to be placed on the lower die toward the forming region, a stripper provided to press the pouch film toward the support region to support the pouch film during pressurization by the punch, and a local pressurizing portion that causes the first region of the pouch film pressed by the stripper to be pressed more strongly than the second region.

[0011] In another example, the local pressurizing portion may include a protrusion provided on one of the stripper and the support area facing the stripper, and a recessed portion provided corresponding to the protrusion on the other of the stripper and the support area facing the stripper.

[0012] In another example, the protrusion may be formed to protrude toward the recessed portion, and the recessed portion may be formed to be recessed to accommodate the protrusion.

[0013] In another example, the protrusion may include a long-side parallel protrusion arranged parallel to a long side of the border of the forming region, and a short-side parallel protrusion arranged parallel to a short side extending perpendicularly from the long side of the border of the forming region.

[0014] In another example, the end of the long-side parallel protrusion may protrude further outward along the extension direction of the long-side parallel protrusion than the end of the long side among the edges of the forming region.

[0015] In another example, the end of the short-side parallel protrusion may protrude further outward along the extension direction of the short-side parallel protrusion than the end of the short side among the edges of the forming region.

[0016] In another example, the end of the long-side parallel protrusion may be positioned adjacent to the end of the short-side parallel protrusion, but may not be connected to the short-side parallel protrusion.

[0017] In another example, the protrusion may further include a longitudinally inclined protrusion extending at an angle relative to the longitudinally parallel protrusion from an end of the longitudinally parallel protrusion.

[0018] In another example, the protrusion may further include a short-sided inclined protrusion extending obliquely with respect to the short-sided parallel protrusion from an end of the short-sided parallel protrusion.

[0019] In another example, the protrusion may further include a guide protrusion extending across between the end of the long-side parallel protrusion and the end of the short-side parallel protrusion.

[0020] In another example, the protrusion may further include a guide protrusion extending in a direction that blocks between the end of the long-side parallel protrusion and the end of the short-side parallel protrusion.

[0021] In another example, the height of the protrusion may be greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0022] In another example, the protrusion may have a horizontal portion formed horizontally and spaced upwardly from the support area, a curved portion having a curved shape extending from one end of the horizontal portion, and a vertical portion extending toward the support area from an end of both ends of the curved portion that is not connected to the horizontal portion.

[0023] In another example, the stripper may include a stripper body having a pressing surface configured to press the pouch film, forming an outer shape of the stripper, a ceiling inner wall formed horizontally inside the stripper body, a vertical inner wall formed vertically upward from the pressing surface inside the stripper body to define the recessed portion together with the ceiling inner wall, and a curved connecting portion connecting a lower end of the vertical inner wall and the pressing surface.

[0024] In another example, the local pressurizing portion may include a protruding plate disposed on the support area, and a cover that covers at least a portion of the support area from above the support area while the protruding plate is disposed on the inside, and the cover may partially protrude toward the stripper due to the protruding plate disposed on the inside.

[0025] In another example, the pouch film may include a metal layer of stainless steel.

[0026] According to the present invention, by locally strongly pressurizing the pouch film through a local pressurizing section, it is possible to reduce or prevent the occurrence of cracks or wrinkles in the pouch film during forming of the pouch film.

[0027] Figure 1 is a drawing illustrating an example of a pouch-type secondary battery.

[0028] Figure 2 is a perspective view illustrating a pouch manufacturing device according to Example 1 of the present invention.

[0029] Figure 3 is a cross-sectional view of the pouch manufacturing device of Figure 2.

[0030] Figure 4 is a plan view of the lower die of Figure 2 viewed from above.

[0031] Fig. 5 is a perspective view of a pouch film formed by the pouch manufacturing device of Fig. 2.

[0032] Fig. 6 is a plan view showing a first modified example of the protrusion of Fig. 2.

[0033] Fig. 7 is a plan view showing a second modified example of the protrusion of Fig. 2.

[0034] Fig. 8 is a plan view showing a third modified example of the protrusion of Fig. 2.

[0035] Fig. 9 is a plan view showing a fourth modified example of the protrusion of Fig. 2.

[0036] Fig. 10 is an enlarged cross-sectional view of the local pressurization section of Fig. 3.

[0037] Fig. 11 is a cross-sectional view illustrating a pouch manufacturing device according to Example 2 of the present invention.

[0038] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0039] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0040] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0041] Example 1

[0042] Fig. 2 is a perspective view illustrating a pouch manufacturing device according to Embodiment 1 of the present invention, and Fig. 3 is a cross-sectional view of the pouch manufacturing device of Fig. 2. The pouch manufacturing device according to Embodiment 1 of the present invention may include a lower die (110), a punch (130), and a stripper (150) as illustrated in Figs. 2 and 3. For reference, the contents of Embodiment 1 may be equally applied to the embodiments described below, as long as they do not conflict with each other.

[0043] Basic structure of pouch manufacturing device

[0044] The lower die (110) may include a forming region (111) that is formed to be inwardly recessed for forming a cup portion (21; see FIG. 5) on a pouch film (F; see FIG. 3). The forming region (111) may be a groove or hole formed by being recessed downward in an upper surface (117) of a lower die body (115) that forms an outer shape of the lower die (110). The lower die (110) may include a support region (113) that is formed to be generally flat on the outside of the forming region (111). The support region (113) may be all or part of the upper surface (117) of the lower die body (115) that surrounds the forming region (111).

[0045] The punch (130) may be a block provided to pressurize the pouch film (F) placed on the lower die (110) toward the forming area (111). By this pressing, a cup portion (21) may be formed in the pouch film (F). The punch (130) may be supported by an upper die (120) that is placed spaced apart from the lower die (110) upward. A connecting pillar (B) may be provided between the upper die (120) and the lower die (110) to maintain a separation distance. Cylinders (171, 176) for the vertical movement of the punch (130) or the vertical movement of the stripper (150) described later may be placed on the upper die (120).

[0046] The punch (130) may be arranged to move toward the forming region (111) while being supported by the upper die (120). For example, the punch (130) may be connected to a punch cylinder (171) fixed to the upper die (120) and indirectly fixed to the upper die (120), but may be moved up and down with respect to the upper die (120) according to the operation of the punch cylinder (171). The punch cylinder (171) may include a cylinder body (172) and a cylinder rod (173) that reciprocates according to hydraulic pressure supplied to the interior of the cylinder body (172). The punch (130) may be connected to the cylinder rod (173) of the punch cylinder (171).

[0047] The stripper (150) is provided to support the pouch film (F) during pressurization by the punch (130), and may be configured to pressurize the pouch film (F) placed on the lower die (110) toward the support area (113) of the lower die (110). The stripper (150) can fix the pouch film (F) through pressurization. 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 move up and down with respect to the upper die (120) according to the operation of the stripper cylinder (176). The stripper cylinder (176) may include a cylinder body (177) and a cylinder rod (178) that reciprocates according to hydraulic pressure supplied to the interior of the cylinder body (177). The stripper (150) can be connected to a cylinder rod (178). FIG. 2 illustrates a stripper (150) that is formed in the shape of a picture frame having a rectangular shape overall and a rectangular hole (H; see FIG. 3) inside. The punch (130) can move vertically through the stripper (150) through the hole (H) formed in the central portion of the stripper (150).

[0048] Hereinafter, the forming process of a pouch film (F) by the pouch manufacturing device of the present embodiment will be described with reference to FIG. 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) can pressurize the pouch film (F) placed on the support area (113) of the lower die (110) to fix the pouch film (F) during the forming of the pouch film (F). Next, the punch (130) is lowered by the punch cylinder (171). As a result, the pouch film (F) is pressed, so that the cup portion (21; see FIG. 5) can be formed. Next, the punch (130) is raised by the punch cylinder (171).

[0049] Local pressurization section of pouch manufacturing device

[0050] The pouch manufacturing device according to Embodiment 1 of the present invention may include a local pressurizing unit (190) as illustrated in FIGS. 2 and 3. The local pressurizing unit (190) may cause the first region (F1; see FIG. 3) and the second region (F2) of the pouch film (F) to be pressed more strongly than the second region (F2) among the first region (F1; see FIG. 3) and the second region (F2) of the pouch film (F) pressed by the stripper (150). The first region (F1) may be any 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 dividing a portion of a pouch film (F) located between a stripper (150) and a support area (113) into two or more areas, one of these areas may be a first area (F1) and the other may be a second area (F2). FIG. 3 illustrates an example in which a portion corresponding to a protrusion (191) to be described later is a first area (F1) and the remaining portion is a second area (F2). The local pressurizing portion (190) may cause a portion (the first area) of the portions (e.g., the first area and the second area) located between the stripper (150) and the support area (113) of the pouch film (F) to be more strongly pressed.

[0051] The local pressurization unit (190) can reduce or prevent cracks or wrinkles from occurring in the pouch film (F) during molding through such local pressurization. If there is no local pressurization unit (190), the portion of the pouch film (F) located between the stripper (150) and the support area (113) will be generally uniformly pressed by the stripper (150) during molding. However, such uniform pressurization can easily cause wrinkles and the like to occur around the portion of the pouch film (F) that is pressed by the punch (130). However, if the local pressurization unit (190) is provided, some portions (first area) of the portion of the pouch film (F) located between the stripper (150) and the support area (113) can be pressed more strongly, thereby causing less wrinkles and the like to occur.

[0052] The local pressurization portion (190) may include a protrusion (191) provided on one of the stripper (150) and the support area (113) facing the stripper (150). The local pressurization portion (190) may include a recessed portion (193) provided on the other of the stripper (150) and the support area (113) facing the stripper (150). FIGS. 2 and 3 illustrate a recessed portion (193) formed on the stripper (150) and a protrusion (191) formed on the support area (113).

[0053] The protrusion (191) may be formed to correspond to the recessed portion (193). Here, the correspondence may be a correspondence of position rather than a correspondence of shape. For example, the protrusion (191) may have a semicircular cross-section, while the recessed portion (193) may have a square cross-section. However, the protrusion (191) and the recessed portion (193) may be formed at a position where they meet each other when the stripper (150) and the support area (113) come into contact with each other due to the movement of the stripper (150).

[0054] 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 area (113) come into contact with each other due to the movement of the stripper (150), the protrusion (191) may be inserted into the recess (193).

[0055] When the protrusion (191) and the depression (193) are formed, the portion of the pouch film (F) that is pressed by the protrusion (191) (e.g., the first region) can be pressed more strongly by the facing surfaces of the stripper (150) and the support region (113) than the portion that is pressed without the protrusion (191) (e.g., the second region).

[0056] Meanwhile, the protrusion (191) may include a long-side parallel protrusion (191L) arranged parallel to the long side (L) of the edge of the forming region (111), as illustrated in FIG. 4, and a short-side parallel protrusion (191S) arranged parallel to the short side (S) extending vertically from the long side (L) of the edge of the forming region (111). FIG. 4 is a plan view of the lower die (110) of FIG. 2 viewed from above. The recessed portion (193) may also include a long-side parallel recessed portion (193L; see FIG. 2) corresponding to the long-side parallel protrusion (191L), and a short-side parallel recessed portion (193S; see FIG. 2) corresponding to the short-side parallel protrusion (191S).

[0057] When configured in this way, the protrusions (191) and the recessed portions (193) can be arranged to at least partially surround the portion of the pouch film (F) that is pressed by the punch (130), thereby further suppressing the occurrence of wrinkles, etc. In order to entirely 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) can be provided, as illustrated in FIG. 4. The same applies to the long-side parallel recessed portions (193L) and the short-side parallel recessed portions (193S). For reference, when the forming region (111) is formed with 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, if the forming area (111) is formed with a square cross-section, the long side (L) and short side (S) of the forming area (111) in this specification may be sides of the same length.

[0058] Meanwhile, the end of the long-side parallel protrusion (191L) may be formed to protrude further outward along the extension direction of the long-side parallel protrusion (191L) than the end of the long side (L) among the edges of the forming region (111) (see A1 of FIG. 4). Both ends of the long-side parallel protrusion (191L) may be formed to protrude further outward than both ends of the long side (L) among the edges of the forming region (111). The long-side parallel recessed portion (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 along the extension direction of the short-side parallel protrusion (191S) than the end of the short side (S) among the edges of the forming region (111) (see A2 of FIG. 4). Both ends of the short-side parallel protrusion (191S) can be formed to protrude further outward than both ends of the short side (S) among the edges of the forming area (111). The short-side parallel recessed portion (193S) can also be formed to correspond to the short-side parallel protrusion (191S).

[0059] The end of the long-side parallel protrusion (191L) may be positioned adjacent to the end of the short-side parallel protrusion (191S), but may not be connected to the short-side parallel protrusion (191S). Correspondingly, a long-side parallel recessed portion (193L) and a short-side parallel recessed portion (193S) may be formed. It may be effective in suppressing the occurrence of wrinkles if the long-side parallel protrusion (191L) and the short-side parallel protrusion (191S) are arranged to almost entirely surround the forming area (111) of the lower die (110). However, when the long-side parallel protrusion (191L) and the short-side parallel protrusion (191S) entirely surround the forming area (111), wrinkles may be induced around the vertex formed by the meeting of the long-side parallel protrusion (191L) and the short-side parallel protrusion (191S).

[0060] When a pouch film (F) is formed by the manufacturing device of the present embodiment, a pouch film having a shape of FIG. 5 can be obtained. FIG. 5 is a perspective view of a pouch film formed by the pouch manufacturing device of FIG. 2. When a 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. When two sheets of the pouch film of FIG. 5 are prepared and the two sheets of pouch films are joined together while an electrode assembly is interposed, a pouch-type battery can be obtained. The portion where the groove portion (30) is formed can be cut during the manufacturing process of the pouch-type battery.

[0061] Meanwhile, the protrusion (191) may further include a long-side inclined protrusion (191I1) extending obliquely with respect to the long-side parallel protrusion (191L) from the end of the long-side parallel protrusion (191L), as illustrated in FIG. 6. The protrusion (191) may further include a short-side inclined protrusion (191I2) extending obliquely with respect to the short-side parallel protrusion (191S) from the end of the short-side parallel protrusion (191S), as illustrated in FIG. 6. FIG. 6 is a plan view illustrating a first modified example of the protrusion of FIG. 2. Long-side inclined protrusions (191I1) may be arranged at each end of the long-side parallel protrusion (191L). Short-side inclined protrusions (191I2) may also be arranged at each end of the short-side parallel protrusion (191S). The inclined protrusions (191I1, 191I2) may not be connected to each other. The inclined protrusions (191I1, 191I2) may extend inclinedly from each end in a direction away from a vertex formed by the meeting of the long side (L) and the short side (S) among the edges of the forming region (111). The inclined protrusions (191I1, 191I2) may guide the flow of the pouch film (F; see FIG. 3) that may occur near the upper vertex during the forming of the pouch film, and the resulting improvement in fluidity may further suppress the occurrence of wrinkles near the upper vertex.

[0062] The protrusion (191) of Fig. 2 can be modified as shown in Fig. 7. Fig. 7 is a plan view illustrating a second modified example 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 obliquely with respect to the long-side parallel protrusion (191L') from an end of the long-side parallel protrusion (191L'). The protrusion (191') may further include a short-side inclined protrusion (191I2') extending obliquely with respect to the short-side parallel protrusion (191S') from an end of the short-side parallel protrusion (191S'). Unlike the inclined protrusions (191I1, 191I2) of FIG. 6, the inclined protrusions (191I1, 191I2) of FIG. 7 may extend inclinedly at each end in a direction approaching a vertex between the long side (L) and the short side (S). For example, the inclined protrusions (191I1, 191I2) of FIG. 7 may extend facing each other at each end. The inclined protrusions (191I1, 191I2) of FIG. 7 may also further suppress the occurrence of wrinkles near the upper vertex.

[0063] The protrusion (191) of Fig. 2 can be modified as shown in Fig. 8. Fig. 8 is a plan view showing a third modified example of the protrusion of Fig. 2. The protrusion (191'') of Fig. 8 can include a long-side parallel protrusion (191L'') and a short-side parallel protrusion (191S''). The protrusion (191'') can further include a guide protrusion (191G'') extending so as to cross 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'') can extend in a direction connecting the vertex formed by the meeting of the extension line of the long-side parallel protrusion (191L'') and the extension line of the short-side parallel protrusion (191S'') and the vertex formed by the meeting of the long side (L) and the short side (S) of the forming area (111). FIG. 8 exemplarily illustrates four guide protrusions (191G'') provided to correspond to the four vertices of the forming area (111). The guide protrusions (191G'') can guide the flow of the pouch film (F) that may occur near the vertices of the forming area (111) during forming of the pouch film (F), and the resulting improvement in fluidity can further suppress the occurrence of wrinkles near the above vertices.

[0064] The protrusion (191) of Fig. 2 can be modified as shown in Fig. 9. Fig. 9 is a plan view showing a fourth modified example of the protrusion of Fig. 2. The protrusion (191''') of Fig. 9 can include a long-side parallel protrusion (191L''') and a short-side parallel protrusion (191S'''). The protrusion (191''') can further include a guide protrusion (191G''') extending in a direction that blocks 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 crossing a straight line connecting a vertex formed by the meeting of an extension line of a long-side parallel protrusion (191L''') and an extension line of a short-side parallel protrusion (191S''') and a vertex formed by the meeting of a long side (L) and a short side (S) of the forming region (111). The guide protrusion (191G''') may extend generally parallel to a straight line connecting an end of a long-side parallel protrusion (191L''') and an end of a short-side parallel protrusion (191S'''). FIG. 9 exemplarily illustrates four guide protrusions (191G''') provided to correspond to four vertices of the forming region (111). The guide protrusion (191G''') of Fig. 9 can also further suppress the occurrence of wrinkles near the vertex of the forming area (111).

[0065] Protrusions and depressions of the local pressure area

[0066] Referring to Fig. 10, the protrusion (191) and the recessed portion (193) of the local pressurizing portion (190) will be described in detail. Fig. 10 is an enlarged cross-sectional view of the local pressurizing portion of Fig. 3.

[0067] The protrusion (191) may include a horizontal portion (191H) formed horizontally, a vertical portion (191V) formed vertically, and a curved portion (191R) having a curved shape connecting them. When the protrusion (191) is formed in the support area (113) of the lower die (110), the horizontal portion (191H) may be positioned spaced upward from the support area (113). The curved portion (191R) may extend from one end of the horizontal portion (191H). The curved portion (191R) may also extend from each of the ends of both sides of the horizontal portion (191H). The vertical portion (191V) may extend toward the support area (113) from an end of the curved portion (191R) that is not connected to the horizontal portion (191H).

[0068] If the protrusion (191) includes a curved portion (191R), the corners of the protrusion (191) are formed gently, thereby preventing the pouch film (F) from being damaged during pressurization by the local pressurizing portion (190). For reference, the horizontal portion (191H), vertical portion (191V), and curved portion (191R) of the protrusion (191) may each be one of several surfaces of the protrusion (191).

[0069] The recessed portion (193) may be defined as a space surrounded by inner walls (193H, 193V) formed inside a stripper body (151) forming the outer shape of the stripper (150). More specifically, the stripper (150) may include a stripper body (151) forming the outer shape of the stripper (150), a ceiling inner wall (193H) formed horizontally inside the stripper body (151), and a vertical inner wall (193V) formed vertically upward from a pressurized surface (152) of the stripper body (151) inside the stripper body (151). The vertical inner wall (193V) may define the recessed portion (193) together with the ceiling inner wall (193H).

[0070] The stripper (150) may include a curved connecting portion (193R) connecting the lower end of the vertical inner wall (193V) and the pressurizing surface (152). The connecting portion (193R) may prevent the pouch film (F) from being damaged during pressurization by the local pressurizing portion (190) through its gently curved shape. For reference, the pressurizing surface (152) of the stripper body (151) is a portion provided to pressurize the pouch film (F) and may be a part of the outer bottom surface of the stripper body (151).

[0071] Meanwhile, the height of the protrusion (191) (H1; see FIG. 3), for example, the distance from the upper surface of the support area (113) to the horizontal portion (191H; see FIG. 10) of the protrusion (191), 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, wrinkle formation may not be sufficiently prevented.

[0072] Structure of pouch film (F)

[0073] Meanwhile, there has been a recent demand for pouch-type batteries that vent only at specific points, even at very high temperatures (e.g., 1,000°C). Conventional pouch-type batteries typically form a sealing portion (23; see Fig. 1) by thermal fusion between resin layers (which may be polypropylene layers) of a pouch film (F). However, at very high temperatures, the resin layers may melt, causing venting at unintended points.

[0074] To address this issue, welding between layers of metals with very high melting points (e.g., stainless steel) can be considered to form a seal. This method of forming a seal provides a high sealing strength, preventing it from breaking even at very high temperatures.

[0075] The pouch manufacturing device of the present embodiment may be 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 molding is performed using a conventional manufacturing device, cracks, etc. are very likely to occur in the pouch film (F) during molding. However, the pouch manufacturing device of the present embodiment can minimize the occurrence of cracks, etc. even in such cases.

[0076] For reference, the pouch film (F) may include a metal layer including stainless steel, a first resin layer disposed on the inside of the metal layer, and a second resin layer disposed on the outside of the metal layer. The first resin layer may be a layer formed of polypropylene (PP). The first resin layer requires high insulation and corrosion resistance, and may be formed of another resin that satisfies these requirements. The first resin layer may not be provided in a portion where welding of the metal layers is required. The second resin layer may be a layer formed of polyethylene terephthalate (PET). The second resin layer needs to protect the secondary battery while electrically insulating the secondary battery, and may be formed of another resin that satisfies these requirements. In the case of the pouch film (F), either the first resin layer or the second resin layer may be provided, or neither of them may be provided.

[0077] Example 2

[0078] Fig. 11 is a cross-sectional view illustrating a pouch manufacturing device according to Embodiment 2 of the present invention. As illustrated in Fig. 11, the pouch manufacturing device according to the present embodiment differs from the device of Embodiment 1 in the structure of the local pressurizing portion. For reference, the contents of Embodiment 2 may be equally applied to the aforementioned embodiments, as long as they do not conflict with each other.

[0079] The local pressurizing portion (190') of the present embodiment may include a protruding plate (196) disposed on the support area (113) of the lower die (110). The protruding plate (196) may be formed of an elastic material that is elastically deformed during pressurization 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 area (111) similarly to the arrangement of the protruding portion (191) of FIG. 4. Alternatively, the protruding plate (196) may be disposed adjacent to a vertex formed by the meeting of the long side (L; see FIG. 4) and the short side (S) of the forming area (111). In this case, a protruding plate (196) may be disposed at each of the four vertices.

[0080] The local pressurizing portion (190') of the present embodiment may include a cover (197) that covers at least a portion of the support area (113) on the upper side of the support area (113) while the protruding plate (196) is disposed on the inside. The cover (197) may partially protrude toward the stripper (150) due to the protruding plate (196) disposed on the inside. This protrusion may perform the role of the protrusion (191) described above. For reference, the cover (197) may also be fixed to the lower die (110) by an adhesive material or a fastening member, etc.

[0081] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0082] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0083] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. A lower die including a forming area formed to be indented inwardly to form a cup portion on a pouch film, and a support area formed flat on the outside of the forming area; A punch provided to press the pouch film to be placed on the lower die toward the forming area; A stripper provided to press the pouch film toward the support area to support the pouch film during pressurization by the punch; and A pouch manufacturing device comprising a local pressurizing section that causes the first region among the first region and the second region of the pouch film that are pressurized by the stripper to be pressed more strongly than the second region.

2. In claim 1, The above local pressurized part is, A protrusion provided on one of the above strippers and the above support areas facing the strippers; and A pouch manufacturing device comprising a recessed portion provided corresponding to the protrusion in the other of the support areas facing the stripper and the stripper.

3. In claim 2, The above protrusion is formed to protrude toward the above recessed portion, A pouch manufacturing device, wherein the above-mentioned recessed portion is formed to be recessed to accommodate the above-mentioned protrusion.

4. In claim 2, The above protrusion is, A pouch manufacturing device comprising a long-side parallel protrusion arranged parallel to a long side of the boundary of the forming region, and a short-side parallel protrusion arranged parallel to a short side extending vertically from the long side of the boundary of the forming region.

5. In claim 4, The ends of the above long parallel projections are, A pouch manufacturing device, wherein the edge of the forming area protrudes outward further along the extension direction of the long side parallel protrusion than the end of the long side.

6. In claim 4, The end of the above short-sided parallel projection is, A pouch manufacturing device, wherein the edge of the forming area protrudes outward further along the extension direction of the short-side parallel protrusion than the end of the short-side.

7. In claim 4, The ends of the above long parallel projections are, A pouch manufacturing device positioned adjacent to the end of the short-sided parallel protrusion, but not connected to the short-sided parallel protrusion.

8. In claim 4, The above protrusion is, A pouch manufacturing device further comprising a long-side inclined protrusion extending obliquely with respect to the long-side parallel protrusion from an end of the long-side parallel protrusion.

9. In claim 4, The above protrusion is, A pouch manufacturing device further comprising a short-sided inclined protrusion extending obliquely with respect to the short-sided parallel protrusion from an end of the short-sided parallel protrusion.

10. In claim 7, The above protrusion is, A pouch manufacturing device further comprising a guide protrusion extending so as to cross between the end of the long-side parallel protrusion and the end of the short-side parallel protrusion.

11. In claim 7, The above protrusion is, A pouch manufacturing device further comprising a guide protrusion extending in a direction that blocks between the end of the long-side parallel protrusion and the end of the short-side parallel protrusion.

12. In claim 2, A pouch manufacturing device, wherein the height of the above protrusion is 0.5 mm or more and less than 2 mm.

13. In claim 2, The above protrusion is, A horizontal portion formed horizontally and spaced upward from the above support area; A curved portion having a curved shape extending from one end of the horizontal portion; and A pouch manufacturing device having a vertical portion extending toward the support area from an end of both ends of the curved portion that is not connected to the horizontal portion.

14. In claim 2, The above stripper, A stripper body having a pressing surface configured to pressurize the above pouch film and forming the outer shape of the stripper; A ceiling inner wall formed horizontally inside the above stripper body; A vertical inner wall formed inside the stripper body, vertically formed upward from the pressure surface and defining the recessed portion together with the ceiling inner wall; and A pouch manufacturing device comprising a curved connecting portion connecting the lower end of the vertical inner wall and the pressurized surface.

15. In claim 1, The above local pressurized part is, a protruding plate disposed on the above support area; and Including a cover that covers at least a portion of the support area on the upper side of the support area while the protruding plate is placed on the inside, A pouch manufacturing device in which the above cover partially protrudes toward the stripper due to the protruding plate disposed on the inside.

16. In claim 1, The above pouch film is a pouch manufacturing device including a metal layer of stainless steel.

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