Battery cell case and method for manufacturing the same

Abstract

The battery cell case and its manufacturing method according to the present invention include a case and a cover, the periphery of which a first edge bend and a second edge bend are formed, respectively, the first edge bend and the second edge bend are overlapped and wound around each other to form a wound structure, and the first edge bend and the second edge bend are folded to form a wrinkled structure located between the wound structure and the periphery of the case and cover. Problems arising in the welding process can be avoided, the requirements for fitting the case and cover can be reduced, the structure can be simplified, and costs can be reduced.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 202310171631.9, titled "Battery Cell Case and Method for Manufacturing the Same", filed with the China National Intellectual Property Administration on February 27, 2023, the entire content of which is incorporated herein by reference.

[0002] This application relates to the field of battery technology, and particularly to battery cell cases and methods for manufacturing the same.

Background Art

[0003] In recent years, with the increasing sales of new energy vehicles, the market demand for driving batteries has been growing. General driving batteries can be classified into cylindrical batteries, square batteries, and soft pack batteries according to their forms. Cylindrical batteries are equipped with a metal shell, usually made of aluminum or steel, and are generally sealed by laser welding. Soft pack batteries are packaged with an aluminum-plastic film and are generally sealed by a high-temperature sealing process.

[0004] Square batteries are equipped with a metal shell and are mainly sealed by laser welding. Specifically, a cover plate is inserted into the upper surface opening of the shell to make it flush, and then the rectangular gap between the cover plate and the shell is welded and sealed by repeating continuous oscillation. According to the position of the welding seam, it can be further divided into two types of sealing processes: top welding and side welding. Here, laser welding of an aluminum shell is difficult and may cause problems such as bulges, pores, sparks, and internal bubbles on the surface of the welding mark, and the requirements for materials and the welding process are high. In the side welding process, bulges occur, which may affect subsequent assembly, so the requirements for the stability of the laser device, the cleanliness of the material, and the fitting gap between the top cover and the shell are high. In the top welding process, if the welding position is not a flat surface, problems are likely to occur in the welding of the four corners, so the requirements for the insertion and positioning of the cover plate on the shell are high, and high-level automation of the equipment is required.

[0005] Therefore, there is an urgent need for sealing structures and methods that can avoid the above-mentioned problems that occur in the welding process. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The primary objective of this application is to provide a battery cell case and a method for manufacturing the same, in order to solve the technical problems of existing welding processes, which are difficult to perform and have high process requirements. [Means for solving the problem]

[0007] The primary objective of this application is to provide a battery cell case and a method for manufacturing the same, in order to solve the technical problems of existing welding processes, which are difficult to perform and have high process requirements.

[0008] To achieve the above-mentioned objective of the invention, this application provides a battery cell case comprising a case and a cover, wherein a first edge bend is formed on the peripheral edge of the case, and a second edge bend is formed on the peripheral edge of the cover, and the first edge bend and the second edge bend are overlapped and wound around each other to form a wound structure.

[0009] The first edge bend portion and the second edge bend portion are folded to form a wrinkle structure, and the wrinkle structure is located between the winding structure and the peripheral edges of the case and the cover.

[0010] Furthermore, the wrinkle structure includes at least one bent projection, which is formed by bending the first edge bent portion and the second edge bent portion, which are planar, in the same direction, in a battery cell case.

[0011] Furthermore, the portions constituting the bent projections of the first and second edge bends are in complete contact.

[0012] Furthermore, the portion constituting the bending projection of the first edge bending portion becomes the first portion, and the portion constituting the bending projection of the second edge bending portion becomes the second portion, where the second portion has a contact portion and a wrinkled portion, the contact portion is in contact with the first portion, and the wrinkled portion is bent in a direction away from the first portion.

[0013] Furthermore, the first portion includes a planar portion parallel to the plane on which the first and second edge-bent portions are located, and a vertical portion perpendicular to the plane on which the first and second edge-bent portions are located, The aforementioned contact portion is in close contact with the flat portion, The wrinkled portion is provided in correspondence with the vertical portion and protrudes along a direction parallel to the plane in which the first edge bend portion and the second edge bend portion are located, with respect to the vertical portion.

[0014] Furthermore, the winding structure is formed by winding the planar first edge bent portion and the second edge bent portion, the winding structure is superimposed on the planar first edge bent portion and the non-winding portion of the second edge bent portion, the portion of the first edge bent portion constituting the winding structure becomes the third portion, and the portion of the second edge bent portion constituting the winding structure becomes the fourth portion, and here, The third portion includes an overlapping portion and an extension portion, the overlapping portion being superimposed on the fourth portion, and the extension portion being bent from the outer edge of the overlapping portion and extending to the side of the fourth portion opposite to the overlapping portion, and superimposed on the fourth portion.

[0015] Furthermore, a sealing layer is provided between the two overlapping surfaces of the third and fourth portions.

[0016] As another technical solution, the present invention further provides a method for manufacturing a battery cell case.

[0017] A step of providing a case and a cover, wherein a first edge bend is formed on the periphery of the case, a second edge bend is formed on the periphery of the cover, the first edge bend and the second edge bend are planar and can be superimposed on each other, The steps include forming a winding structure by winding the first edge bending portion and the second edge bending portion, A step of forming a wrinkle structure by bending a first edge bending portion and a second edge bending portion, wherein the wrinkle structure is located between the winding structure and the peripheral edges of the case and the cover.

[0018] Furthermore, in the step of providing the case and cover as described above, an extension is formed on the outer periphery of the first edge bend, and the extension is perpendicular to each other with respect to the planar first edge bend and second edge bend. The step of winding the first edge bending portion and the second edge bending portion described above to form a winding structure is, The steps include: bending the extended portion and overlapping it with the second edge bend portion on the side opposite to the first edge bend portion; The steps include: bending the overlapping extension portion, the first edge bend portion, and the second edge bend portion toward the side where the extension portion is located to form an arc portion on the periphery of the overlapping extension portion, the first edge bend portion, and the second edge bend portion; The method includes the steps of winding the extension portion, the first edge bend portion, and a part of the second edge bend portion that form the arc portion toward the side where the extension portion is located, and flattening the arc portion during the winding process so that the extension portion, the first edge bend portion, and a part of the second edge bend portion overlap the unwound portion of the first edge bend portion and the second edge bend portion which are flat.

[0019] Furthermore, the wrinkle structure includes at least one folding projection, In the step of providing the case and cover as described above, the second edge bending portion has a contact portion and a wrinkled portion that constitute the bending projection, The step of forming the wrinkle structure by bending the above-described first edge bending portion and the second edge bending portion is as follows: It includes a step of bending the first edge bending portion in a direction approaching the contact portion, and bringing the portion configured as the bending protrusion by the bending of the first edge bending portion into contact with the contact portion. Here, the wrinkle portion protrudes in a direction away from the portion configured as the bending protrusion by the bending of the first edge bending portion.

Advantages of the Invention

[0020] In the technical solution of the battery cell case and its manufacturing method provided by the present application, a first edge bending portion is formed at the peripheral edge of the case, a second edge bending portion is formed at the peripheral edge of the cover, the first edge bending portion and the second edge bending portion are overlapped with each other and wound to form a winding structure, and this winding structure can integrally seal and join the peripheral edges of the case and the cover. Therefore, it can replace the welding process in the prior art and avoid the problems caused by the welding process. Moreover, the requirements for the fitting of the case and the cover are reduced, the structure is simplified, the equipment investment is reduced, and the cost can be reduced. In addition, the first edge bending portion and the second edge bending portion are bent to form a wrinkle structure, and this wrinkle structure is located between the winding structure and the peripheral edges of the case and the cover. By combining the wrinkle structure and the above winding structure for use, the sealing performance of the case and the cover can be further improved, which is also beneficial to the breathing and expansion of the battery cell. Therefore, the certainty of sealing can be enhanced.

Brief Description of the Drawings

[0021] [Figure 1] It is a partial cross-sectional view of the battery cell case provided by an embodiment of the present invention. [Figure 2] It is an enlarged view of the winding structure and the wrinkle structure in FIG. 1. [Figure 3] It is a partial cross-sectional view of the battery cell case of FIG. 1 before the winding structure and the wrinkle structure are formed. [Figure 4]Another partial cross-sectional view of the battery cell case provided by an embodiment of the present invention. [Figure 5] An enlarged view of the winding structure and the wrinkle structure in FIG. 4. [Figure 6] A partial cross-sectional view of the battery cell case of FIG. 4 before the winding structure and the wrinkle structure are formed. [Figure 7A] An enlarged view showing a sealing layer added to the winding structure of FIG. 2. [Figure 7B] An enlarged view showing a sealing layer added to the winding structure of FIG. 5. [Figure 8] A partial cross-sectional view of the battery cell case of FIG. 7A or FIG. 7B before the winding structure and the wrinkle structure are formed. [Figure 9A] A partial cross-sectional view of the battery cell case at the completion of step S101 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9B] A partial cross-sectional view of the battery cell case at the completion of step S102 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9C] A partial cross-sectional view of the battery cell case at the completion of step S103 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9D] A partial cross-sectional view of the battery cell case at the completion of step S104 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9E] A partial cross-sectional view of the battery cell case at the completion of step S105 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9F] A partial cross-sectional view of the battery cell case at the completion of step S106 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9G] A partial cross-sectional view of the battery cell case at the completion of step S107 of the manufacturing method of the battery cell case provided by an embodiment of the present invention. [Figure 9H]This is a partial cross-sectional view of a battery cell case at the completion of step S108 of the method for manufacturing a battery cell case provided by an embodiment of the present invention. [Modes for carrying out the invention]

[0022] To further clarify the object, technical solution, and advantages of the present invention, the present invention will be described in more detail below with reference to the accompanying drawings. However, it should be noted that the embodiments described are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be obtained by those skilled in the art without creative effort based on the embodiments of the present invention are included within the scope of protection of the present invention.

[0023] The shapes and sizes of the components shown in the attached drawings do not reflect true proportions and are intended solely to facilitate understanding of the embodiments of the present invention.

[0024] Unless otherwise defined, technical or scientific terms used in this disclosure should have the ordinary meanings understood by those skilled in the art of the field to which this disclosure belongs. Terms such as “first,” “second,” etc., used in this disclosure do not indicate any order, number, or importance, but are used solely to distinguish different components. Similarly, similar terms such as “one,” “one,” or “the said,” do not limit the number, but indicate the presence of at least one. Similar terms such as “includes” or “comes with,” mean that the element or object appearing before the term encompasses the elements or objects and their equivalents listed after the term, without excluding other elements or objects. Similar terms such as “connected” or “linked,” are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as “up,” “down,” “left,” and “right” are used solely to indicate relative positional relationships, and if the absolute position of the object being described changes, the relative positional relationships may change accordingly.

[0025] The embodiments of this disclosure are not limited to those shown in the accompanying drawings and include configuration changes formed based on the manufacturing process. Therefore, the regions illustrated in the accompanying drawings have schematic characteristics, and the shapes of the regions shown in the drawings are illustrative of the specific shapes of these regions in the elements, but are not intended to be limiting.

[0026] Referring to Figure 1, the battery cell case provided by an embodiment of the present invention includes a case 1 and a cover 2, wherein a first edge bend 11 is formed on the periphery of case 1 and a second edge bend 21 is formed on the periphery of cover 2, and the first edge bend 11 and the second edge bend 21 are overlapped and wound around each other to form a wound structure 3, which can integrally seal and join the peripheries of case 1 and cover 2, thereby replacing the welding process in the prior art, avoiding problems that occur in the welding process, reducing the requirements for fitting the case and cover, simplifying the structure, reducing capital investment, and lowering costs. The first edge bend 11 and the second edge bend 21 are bent to form a wrinkle structure 4, which is located between the wound structure 3 and the peripheries of case 1 and cover 2. By using the wrinkle structure 4 in combination with the winding structure 3 described above, the airtightness of the case 1 and cover 2 can be further improved, which is also advantageous for the breathing and expansion of the battery cells, and thus the reliability of the seal can be increased.

[0027] Specifically, case 1 is, for example, a square case or a rectangular case, and an opening for arranging battery cells is provided at one end of case 1. Cover 2 is, for example, a cover plate, and when joined to case 1, the cover plate seals the opening and, together with case 1, can form a sealed space for housing battery cells.

[0028] In some selectable embodiments, as shown in Figure 3, the first edge bend 11 and the second edge bend 21 are laid flat, i.e., planar, before forming the winding structure 3 and the wrinkle structure 4. Optionally, before forming the winding structure 3 and the wrinkle structure 4, both the first edge bend 11 and the second edge bend 21 are located in a plane perpendicular to the orientation of the opening of the case 1. For example, in Figure 3, the orientation of the opening of the case 1 is parallel to the Y direction and upward, and the planar first edge bend 11 and the second edge bend 21 are located in a plane perpendicular to the Y direction and parallel to the X direction. Of course, in actual applications, depending on specific needs, the angle between the plane on which the first edge bend 11 and the second edge bend 21 are located and the orientation of the opening of the case 1 may be other than 90°, and there are no particular limitations in embodiments of the present invention. It should be explained that in actual applications, the first edge bend portion 11 and the second edge bend portion 21 may be non-planar, for example, arcuate, before forming the above-mentioned winding structure 3 and wrinkle structure 4, as long as they can form the above-mentioned winding structure and wrinkle structure by winding and folding, and there are no particular limitations in the embodiments of the present invention.

[0029] In some selectable embodiments, as shown in Figure 2, the wrinkle structure 4 includes at least one bent projection, which shows a single bent projection formed by bending a planar first edge bend 11 and a second edge bend 21 in the same direction. The bent projection shown in Figure 2 is formed by bending the planar first edge bend 11 and the second edge bend 21 upwards. The bent projection not only lengthens the gap between the cover 2 and the case 1, creating a labyrinthine gap that further improves the airtightness between the case 1 and the cover 2, but is also advantageous for the breathing and expansion of the battery cells, thus increasing the reliability of the seal. Furthermore, the above-mentioned bent projection has a simple structure and is easy to process.

[0030] In some selectable embodiments, as shown in Figure 2, the portions (114, 213) constituting the bending protrusions of the first edge bend 11 and the second edge bend 12 are in complete contact, that is, referring together with Figure 3, the portions (114, 213) constituting the bending protrusions of the first edge bend 11 and the second edge bend 21 are always overlapping before and after the bending process. However, the embodiments of the present invention are not limited thereto, and in other selectable embodiments, the portions constituting the bent projections of the first edge bend portion 11 and the second edge bend portion 21 do not have to be in complete contact. For example, referring together to Figures 4 and 5, the portion constituting the bent projection of the first edge bend portion 11 becomes the first portion 114, and the portion constituting the bent projection of the second edge bend portion becomes the second portion 213', where the second portion 213' has a contact portion 213a and a wrinkled portion 213b, the contact portion 213a is in contact with the first portion 114, and the wrinkled portion 213b is bent away from the first portion 114. This wrinkled portion 213b is advantageous for the breathing and expansion of the battery cell and can further enhance the reliability of the seal.

[0031] The structure of the wrinkled portion 213b may vary. For example, the first portion 114 includes a planar portion 114a parallel to the plane on which the planar first edge bend portion 11 and second edge bend portion 21 are located, and a vertical portion 114b perpendicular to the plane on which the planar first edge bend portion and second edge bend portion are located. That is, the planar portion 114a is parallel to the X direction, and the vertical portion 114b is parallel to the Y direction. Here, the adhering portion 213a adheres to the planar portion 114a, and the wrinkled portion 213b is provided in correspondence with the vertical portion 114b and protrudes from the vertical portion 114b in a direction parallel to the plane on which the planar first edge bend portion 11 and second edge bend portion 21 are located, that is, in a direction parallel to the X direction and away from the vertical portion 114b, towards the left side of Figure 5. In this way, an effect favorable to the breathing and expansion of the battery cell is obtained, and the wrinkled portion 213b can be made flush with the surface of the cover 2 opposite to the case, so that no protrusions are created on the outer contour of the cover.

[0032] In some selectable embodiments, as shown in Figures 2 and 5, there is one bending projection that protrudes in the same direction as the opening of the case 1 relative to the unbent portions (111, 211) of the planar first edge bend 11 and second edge bend 21. For example, as shown in Figure 5, the opening of the case 1 is parallel to the Y direction and points upward, and the bending projection protrudes upward along the direction parallel to the Y direction. Of course, embodiments of the present invention are not limited thereto, and in actual applications, the bending projection may protrude in the opposite direction to the opening of the case 1. There may be multiple bending projections, and the projection directions of the multiple bending projections may be the same or different. For example, multiple bending projections can form a wavy wrinkle structure.

[0033] In some selectable embodiments, the longitudinal cross-sectional shape of the bent projection may be, for example, rectangular, square, arc-shaped, or trapezoidal. For example, the longitudinal cross-sectional shape of the bent projection in Figures 2 and 5 is rectangular, and optionally, the corners of the bent projection are rounded.

[0034] In some selectable embodiments, as shown in Figures 2 and 5, the winding structure 3 is formed by winding the planar first edge bends 11 and second edge bends 21, and the winding structure 3 is superimposed on the unwinding portions (111, 211) of the planar first edge bends 11 and second edge bends 21. In other words, the first edge bends 11 and second edge bends 21 are laid flat, i.e., planar, as shown in Figures 3 and 6, before the winding structure 4 is formed. The edges of the planar first edge bends 11 and second edge bends 21 near the outer periphery are wound to form the winding structure 3, while the rest of the edges are not wound and remain planar. Furthermore, these edges are superimposed on the unwinding portions (111, 211) after being wound. This helps to enhance the sealing effect. Optionally, the winding structure 3 is superimposed on the side of the non-winding portion (111, 211) adjacent to the second edge bend portion 21, i.e., on the upper side of the second edge bend portion 21 in Figures 2 and 5. Of course, in actual applications, depending on the specific requirements, the winding structure may be wound in the reverse direction and superimposed on the side of the non-winding portion adjacent to the first edge bend portion. Furthermore, optionally, the planes on which the planar non-winding portion (111, 211) is located are perpendicular to each other with respect to the orientation of the opening of the case 1.

[0035] Furthermore, as shown in Figures 2 and 5, the portion of the first edge bend 11 that constitutes the winding structure 3 becomes the third portion, and the portion of the second edge bend 21 that constitutes the winding structure 3 becomes the fourth portion 212, where the third portion includes an overlapping portion 112 and an extension portion 113, the overlapping portion 112 overlapping with the fourth portion 212, and the extension portion 113 is bent from the outer peripheral edge of the overlapping portion 112 and extends to the side of the fourth portion 212 opposite to the overlapping portion 112, and overlaps with the fourth portion 212. Specifically, the first edge bend 11 extends in part with respect to the outer peripheral edge of the second edge bend 21, and this part becomes the extension portion 113, and optionally, as shown in Figures 3 and 6, in order to facilitate the attachment of the cover 2, the extension portion 113' before winding is parallel to each other with respect to the orientation of the opening of the case 1 (or forms an obtuse angle greater than 90°). This extension 113 can cover the periphery of the fourth portion 212, thereby closing the gap between the first edge bend 11 and the second edge bend 21 and isolating it from the outside.

[0036] In some optional embodiments, as shown in Figures 7A and 7B, a seal layer 5 is provided between the two overlapping surfaces of the third portion (including the overlap 112 and extension 113) and the fourth portion 212. This seal layer 5 is made of, for example, a sealant or other sealing material. The seal layer 5 can further enhance the pressure resistance and airtightness of the winding structure 3. Optionally, the structure of the seal layer 5' before winding may be attached to the surfaces of the extension 113' and overlap 112' adjacent to the cover 2 before winding, as shown in Figure 8.

[0037] As another technical solution, embodiments of the present invention further provide a method for manufacturing a battery cell case, taking as an example the manufacturing of a battery cell case as shown in Figures 1 to 3 or Figures 4 to 6, the method includes the following:

[0038] S1 provides a case 1 and a cover 2, wherein a first edge bend portion 11 is formed on the periphery of case 1 and a second edge bend portion 21 is formed on the periphery of cover 2, and the first edge bend portion 11 and the second edge bend portion 21 are planar and overlap each other.

[0039] The first edge bend portion 11 and the second edge bend portion 21 are laid flat, i.e., planar, as shown in Figures 3 and 6, before the winding structure 3 and wrinkle structure 4 are formed. Optionally, before the winding structure 3 and wrinkle structure 4 are formed, the planes on which the first edge bend portion 11 and the second edge bend portion 21 are located are perpendicular to each other with respect to the orientation of the case opening. Of course, in actual applications, depending on the specific requirements, the angle between the planes on which the first edge bend portion 11 and the second edge bend portion 21 are located and the orientation of the case opening 1 may be other than 90°, and there are no particular limitations in the embodiments of the present invention. It should be noted that in actual applications, the first edge bend portion 11 and the second edge bend portion 21 may be non-planar, for example, arcuate, before the winding structure 3 and wrinkle structure 4 are formed, as long as the winding structure and wrinkle structure can be formed by winding and bending, and there are no particular limitations in the embodiments of the present invention.

[0040] S2, the first edge bend portion 11 and the second edge bend portion 21 are wound around to form a wound structure 3.

[0041] S3, the first edge bend portion 11 and the second edge bend portion 21 are bent to form a wrinkle structure 4, which is located between the winding structure 3 and the peripheral edges of the case 1 and cover 2.

[0042] In step S1 described above, as shown in Figures 3 and 6, an extension 113 is formed on the outer periphery of the first edge bend 11, and this extension 113 is perpendicular to each other with respect to the planar first edge bend 11 and second edge bend 21. Furthermore, step S2 described above specifically includes the following:

[0043] S21, the extension (i.e., the extension 113' before it is wound) is folded and placed on the side of the second edge bend 21 opposite to the first edge bend 11.

[0044] In S22, the overlapping extensions (i.e., the extensions 113' before winding), the first edge bend 11, and the second edge bend 21 are bent toward the side where the extensions are located, thereby forming arcs on the periphery of the overlapping extensions (i.e., the extensions 113' before winding), the first edge bend 11, and the second edge bend 21.

[0045] The arc portion described above restricts the second edge bend portion 21 between the overlapping extensions (i.e., the extensions 113' before winding) and the first edge bend portion 11, thereby preventing relative movement of the second edge bend portion 21 with respect to the extensions and the first edge bend portion 11. This limits the position of the cover 2 and prevents it from moving during winding.

[0046] In S23, the extension portion forming the arc (i.e., the extension portion 113' before winding), the first edge bend portion 11, and a part of the second edge bend portion 21 are wound toward the side where the extension portion is located, and the arc portion is flattened by tapping it during the winding process, so that the extension portion (i.e., the extension portion 113' before winding), the first edge bend portion 11, and a part of the second edge bend portion 21 are superimposed on the unwound portions (111, 211) of the first edge bend portion and the second edge bend portion which are planar.

[0047] Specifically, the first edge bend portion 11 and the second edge bend portion 21 are laid flat, i.e., planar, before forming the winding structure 3. The edges of the planar first edge bend portion 11 and the second edge bend portion 21 near the outer periphery are wound to form the winding structure 3, while the remaining portions are not wound and remain planar. After being wound, these edges are superimposed on the unwound portions (111, 211). This helps to enhance the sealing effect. Optionally, the winding structure 3 is superimposed on the side of the unwound portions (111, 211) adjacent to the second edge bend portion 21, i.e., on the upper side of the second edge bend portion 21 in Figures 2 and 5. Of course, in actual applications, depending on specific needs, the winding structure may be wound in the reverse direction and superimposed on the side of the unwound portions adjacent to the first edge bend portion. Furthermore, optionally, the planes on which the planar unwound portions are located are perpendicular to each other with respect to the orientation of the case opening.

[0048] The portion of the first edge bend 11 that constitutes the winding structure 3 becomes the third portion, and the portion of the second edge bend 21 that constitutes the winding structure 3 becomes the fourth portion 212, where the third portion includes an overlapping portion 112 and an extension portion 113, the overlapping portion 112 overlapping with the fourth portion 212, and the extension portion 113 is bent from the outer peripheral edge of the overlapping portion 112 and extends to the side of the fourth portion 212 opposite to the overlapping portion 112 and overlaps with the fourth portion 212. Specifically, the first edge bend 11 extends in part with respect to the outer peripheral edge of the second edge bend 21, and that part becomes the extension portion 113, and optionally, in order to facilitate the attachment of the cover 2, the extension portion 113' before winding is parallel to each other with respect to the orientation of the opening of the case 1. This extension 113 can cover the outer edge of the fourth portion 212, thereby closing the gap between the first edge bend 11 and the second edge bend 21 and isolating it from the outside.

[0049] In step S21, the extension (i.e., the extension 113' before winding) is bent and placed on the side of the second edge bend 21 opposite to the first edge bend 11 (i.e., the side of the fourth portion 212 opposite to the overlap 112). In step S22, the extension (i.e., the extension 113' before winding), the overlap 112, and the fourth portion 212 located between them are bent toward the side where the extension is located to form an arc. This arc curves relative to the unbent portion of the extension (i.e., the extension 113' before winding), making it easy to flatten the extension 113, the overlap 112, and the fourth portion 212 located between them by overlapping them with the planar first edge bend 11 and the unwinding portion (111, 211) of the second edge bend 21 in the subsequent step S23.

[0050] In some selectable embodiments, as shown in Figure 5, the wrinkle structure 4 includes at least one folded projection. Based on this, in step S1, the portion constituting the folded projection of the first edge bend 11 becomes the first portion 114, and the portion constituting the folded projection of the second edge bend becomes the second portion 213', where the second portion 213' has an adhering portion 213a and a wrinkled portion 213b. The adhering portion 213a is in close contact with the horizontal portion 114a of the first portion 114, and the wrinkled portion 213b is folded away from the vertical portion 114b of the first portion 114. This wrinkled portion 213b is advantageous for the breathing and expansion of the battery cell and thus can further enhance the reliability of the seal.

[0051] As can be understood, the adhering portion 213a and wrinkled portion 213b of the second edge bend portion 21 are created in advance during the processing of the cover, and in the subsequent step S3, the first edge bend portion 11 is simply bent to finally form the wrinkle structure 3. Specifically, step S3 includes the following:

[0052] The first edge bending portion 11 is bent in a direction approaching the contact portion 213a, and the portion of the first edge bending portion 11 that is bent to form a bent projection (i.e., the horizontal portion 114a of the first portion 114) is brought into close contact with the contact portion 213a.

[0053] Here, the wrinkled portion 213b protrudes away from the portion of the first edge bend 11 that is bent to form a bent projection (i.e., the vertical portion 114b of the first portion 114). In this way, an effect favorable to the breathing and expansion of the battery cell is obtained, and the wrinkled portion can be made flush with the surface of the cover opposite to the case, so that no protrusion is created on the outer contour of the cover.

[0054] In a specific embodiment, referring together to Figures 9A to 9H, the method for manufacturing a battery cell case provided by an embodiment of the present invention includes the following:

[0055] S101, as shown in Figure 9A, the cover 2 is placed on the side of the case 1 where the opening is located to close the opening, and the flat second edge bend portion 21 of the cover 2 is superimposed on the flat first edge bend portion 11 of the case 1.

[0056] The first edge bend portion 11 extends in part with respect to the outer peripheral edge of the second edge bend portion 21, and this part becomes the extension portion 113' before winding, and in order to facilitate the attachment of the cover 2, the extension portions 113' before winding are parallel to each other with respect to the orientation of the opening of the case 1 (or form an obtuse angle greater than 90°).

[0057] S102, as shown in Figure 9B, the extension portion (i.e., the extension portion 113' before winding) is bent in a direction approaching the second edge bending portion 21 and struck so that it overlaps the second edge bending portion 21 with the side opposite to the first edge bending portion 11.

[0058] As shown in Figure 9C, in S103, the overlapping extensions (i.e., the extensions 113' before winding), the first edge bend (i.e., the overlapping portion 112' before winding), and the second edge bend (i.e., the fourth portion 212' before winding) are bent toward the side where the extensions are located, thereby forming arc portions S on the periphery of the overlapping extensions (i.e., the extensions 113' before winding), the first edge bend (i.e., the overlapping portion 112' before winding), and the second edge bend (i.e., the fourth portion 212' before winding).

[0059] The arc portion S restricts the second edge bend portion 21 between the overlapping extensions (i.e., the extensions 113' before winding) and the first edge bend portion 11, thereby preventing relative movement of the second edge bend portion 21 with respect to the extensions and the first edge bend portion 11. This limits the position of the cover 2 and prevents it from moving during winding.

[0060] S104, as shown in Figure 9D, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first edge bend portion (i.e., the overlap portion 112' before winding), and the second edge bend portion (i.e., the fourth portion 212' before winding) are bent at a certain angle (e.g., 30° to 45°) toward the side where the extension portion is located.

[0061] In S105, as shown in Figure 9E, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first edge bend portion (i.e., the overlap portion 112' before winding), and the second edge bend portion (i.e., the fourth portion 212' before winding) are continued to bend by nearly 90° toward the side where the extension portion is located.

[0062] S106, as shown in Figure 9F, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first edge bend portion (i.e., the overlap portion 112' before winding), and the second edge bend portion (i.e., the fourth portion 212' before winding) are continued to bend until they are 90° toward the side where the extension portion is located.

[0063] As shown in S107, Figures 9G and 9H, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first edge bend portion (i.e., the overlapping portion 112' before winding), and the second edge bend portion (i.e., the fourth portion 212' before winding) are pressed and hammered flat, causing the arc portion S to deform into a planar shape and forming a winding structure 3 (including the extension portion 113, the overlapping portion 112, and the fourth portion 212) which is superimposed on the planar non-winding portions (111, 211) of the first edge bend portion 11 and the second edge bend portion 21.

[0064] As shown in Figure 9H, the first edge bend portion 11 and the second edge bend portion 21 are folded to form a wrinkle structure 4.

[0065] In the technical solution for a battery cell case and its manufacturing method provided by embodiments of the present invention, a first edge bend is formed on the periphery of the case, and a second edge bend is formed on the periphery of the cover. The first and second edge bends are overlapped and wound around each other to form a wound structure. This wound structure can integrally seal and join the peripheries of the case and the cover, thus replacing the welding process in the prior art, avoiding problems associated with the welding process, reducing the requirements for fitting the case and cover, simplifying the structure, reducing capital investment, and lowering costs. Furthermore, the first and second edge bends are folded to form a wrinkle structure, which is located between the wound structure and the peripheries of the case and the cover. By using this wrinkle structure in combination with the wound structure, the airtightness of the case and the cover can be further improved, which is also advantageous for the breathing and expansion of the battery cell, and thus the reliability of the sealing can be increased.

[0066] As should be understood, the embodiments described above are merely illustrative examples for illustrating the principles of the present invention and do not limit the invention. Those skilled in the art can make various modifications and improvements without departing from the spirit and essence of the invention, and these are also considered to be within the scope of the invention. [Explanation of symbols]

[0067] 2 Covers 3. Wound structure (wrinkled structure) 4. Wound structure (wrinkled structure) 5 sealing layer 5' sealing layer 11. First edge bending section 12. Second edge bending section 21 Second edge bending section 112 Overlapping section 112' Overlap section 113 Extension 113' extension 114 Part 1 114a Horizontal part (flat part) 114b Vertical section 212 Part 4 212' 4th part 213' 2nd part 213a Contact area 213b Wrinkled area

Claims

1. Including a case and a cover, the case has a first edge bend formed on its periphery, and the cover has a second edge bend formed on its periphery, and the first edge bend and the second edge bend are overlapped and wound around each other to form a wound structure. The first edge bend portion and the second edge bend portion are folded to form a wrinkle structure, and the wrinkle structure is located between the winding structure and the peripheral edges of the case and the cover. The wrinkled structure includes at least one bent projection, which is formed by bending a first edge bent portion and a second edge bent portion, both of which are planar, in the same direction, in a battery cell case.

2. The battery cell case according to claim 1, wherein the portions constituting the first edge bend portion and the second edge bend portion are in complete contact with each other.

3. The battery cell case according to claim 1, wherein the portion constituting the bent projection of the first edge bend is a first portion, and the portion constituting the bent projection of the second edge bend is a second portion, wherein the second portion has a contact portion and a wrinkled portion, the contact portion is in contact with the first portion, and the wrinkled portion is bent in a direction away from the first portion.

4. The first portion includes a planar portion parallel to the plane on which the first and second edge-bent portions are located, and a vertical portion perpendicular to the plane on which the first and second edge-bent portions are located, The aforementioned contact portion is in close contact with the flat portion, The battery cell case according to claim 3, wherein the wrinkled portion is provided in correspondence with the vertical portion and protrudes in a direction parallel to the plane in which the first edge bend portion and the second edge bend portion are located, relative to the vertical portion.

5. The winding structure is formed by winding the planar first edge bent portion and the second edge bent portion, the winding structure is superimposed on the planar first edge bent portion and the non-winding portion of the second edge bent portion, the portion of the first edge bent portion constituting the winding structure becomes the third portion, and the portion of the second edge bent portion constituting the winding structure becomes the fourth portion, and here, The battery cell case according to claim 1, wherein the third portion includes an overlapping portion and an extension portion, the overlapping portion overlapping with the fourth portion, and the extension portion being bent from the outer peripheral edge of the overlapping portion and extending to the side of the fourth portion opposite to the overlapping portion and overlapping with the fourth portion.

6. The winding structure is formed by winding the planar first edge bent portion and the second edge bent portion, the winding structure is superimposed on the planar first edge bent portion and the non-winding portion of the second edge bent portion, the portion of the first edge bent portion constituting the winding structure becomes the third portion, and the portion of the second edge bent portion constituting the winding structure becomes the fourth portion, and here, The battery cell case according to claim 2, wherein the third portion includes an overlapping portion and an extension portion, the overlapping portion overlapping with the fourth portion, and the extension portion being bent from the outer peripheral edge of the overlapping portion and extending to the side of the fourth portion opposite to the overlapping portion and overlapping with the fourth portion.

7. The winding structure is formed by winding the planar first edge bent portion and the second edge bent portion, the winding structure is superimposed on the planar first edge bent portion and the non-winding portion of the second edge bent portion, the portion of the first edge bent portion constituting the winding structure becomes the third portion, and the portion of the second edge bent portion constituting the winding structure becomes the fourth portion, and here, The battery cell case according to claim 3, wherein the third portion includes an overlapping portion and an extension portion, the overlapping portion overlapping with the fourth portion, and the extension portion being bent from the outer peripheral edge of the overlapping portion and extending to the side of the fourth portion opposite to the overlapping portion and overlapping with the fourth portion.

8. The winding structure is formed by winding the planar first edge bent portion and the second edge bent portion, the winding structure is superimposed on the planar first edge bent portion and the non-winding portion of the second edge bent portion, the portion of the first edge bent portion constituting the winding structure becomes the third portion, and the portion of the second edge bent portion constituting the winding structure becomes the fourth portion, and here, The battery cell case according to claim 4, wherein the third portion includes an overlapping portion and an extension portion, the overlapping portion overlapping with the fourth portion, and the extension portion being bent from the outer peripheral edge of the overlapping portion and extending to the side of the fourth portion opposite to the overlapping portion and overlapping with the fourth portion.

9. The battery cell case according to claim 5, wherein a sealing layer is provided between the two overlapping surfaces of the third and fourth portions.

10. The battery cell case according to claim 6, wherein a sealing layer is provided between the two overlapping surfaces of the third and fourth portions.

11. The battery cell case according to claim 7, wherein a sealing layer is provided between the two overlapping surfaces of the third and fourth portions.

12. The battery cell case according to claim 8, wherein a sealing layer is provided between the two overlapping surfaces of the third and fourth portions.

13. A step of providing a case and a cover, wherein a first edge bend is formed on the peripheral edge of the case, a second edge bend is formed on the peripheral edge of the cover, the first edge bend and the second edge bend are planar and can be superimposed on each other, The steps include forming a winding structure by winding the first edge bending portion and the second edge bending portion, A step of forming a wrinkle structure by bending the first edge bending portion and the second edge bending portion, wherein the wrinkle structure is located between the winding structure and the peripheral edges of the case and the cover, A method for manufacturing a battery cell case, comprising the step of bending the first edge bend portion and the second edge bend portion, which are flat, in the same direction to form the folded projection of the wrinkle structure.

14. In the step of providing the case and cover, an extension is formed on the outer periphery of the first edge bend, and the extension is perpendicular to each other with respect to the first edge bend and the second edge bend, which are planar. The step of winding the first edge bent portion and the second edge bent portion to form a winding structure is, The steps include bending the extended portion and overlapping it with the second edge bend portion on the side opposite to the first edge bend portion, The steps include: bending the overlapping extension portion, the first edge bend portion, and the second edge bend portion toward the side where the extension portion is located to form an arc portion on the periphery of the overlapping extension portion, the first edge bend portion, and the second edge bend portion; A method for manufacturing a battery cell case according to claim 13, comprising the steps of winding the extension portion, the first edge bend portion, and a part of the second edge bend portion that form the arc portion toward the side where the extension portion is located, and flattening the arc portion during the winding process so that the extension portion, the first edge bend portion, and a part of the second edge bend portion overlap the unwinding portion of the first edge bend portion and the second edge bend portion which are planar.

15. The wrinkle structure includes at least one folding projection, In the step of providing the case and cover, the second edge bending portion has a contact portion and a wrinkled portion that constitute the bending projection, The step of bending the first edge bend portion and the second edge bend portion to form a wrinkled structure is: The process includes the steps of bending the first edge bend portion in a direction approaching the contact portion, and bringing the portion formed as the bent projection by bending the first edge bend portion into contact with the contact portion, The method for manufacturing a battery cell case according to claim 14, wherein the wrinkled portion protrudes in a direction away from the portion formed as the bent projection by the bending of the first edge bending portion.

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