Battery cell housing and method of manufacturing the same

Abstract

The application provides an electric core shell and a manufacturing method thereof. The electric core shell comprises a shell and a cover. A circumferential edge of the shell is formed with a first curled edge, a circumferential edge of the cover is formed with a second curled edge, the first curled edge and the second curled edge are overlapped with each other and are curled to form a curled edge structure, and the first curled edge and the second curled edge are bent to form a pleat structure between the curled edge structure and the circumferential edges of the shell and the cover. The technical scheme of the electric core shell and the manufacturing method thereof can avoid problems in a welding process, reduce the matching requirements of the shell and the cover, simplify the structure, reduce equipment investment and reduce costs.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to a battery cell casing and its manufacturing method. Background Technology

[0002] In recent years, with the continuous increase in sales of new energy vehicles, the market demand for power batteries has been increasing. Common power batteries can be divided into cylindrical batteries, prismatic batteries, and pouch batteries according to their shape. Cylindrical batteries have a metal casing, usually an aluminum and steel casing, and are generally encapsulated by laser welding; pouch batteries are packaged in aluminum-plastic film and are generally encapsulated by heat sealing process.

[0003] The square battery has a metal casing, and its encapsulation is mainly completed through laser welding. Specifically, a cover plate is inserted into the top opening of the casing, flush with it, and then the rectangular gap between the cover plate and the casing is welded and sealed using repeated laser welding. Depending on the weld location, there are two encapsulation processes: top welding and side welding. Laser welding of aluminum casings is more difficult, and problems such as weld surface protrusions, porosity, sparking, and internal bubbles can occur, requiring high standards for materials and welding processes. Side welding may cause protrusions and affect subsequent assembly; therefore, it places high demands on the stability of the laser, the cleanliness of the materials, and the fit clearance between the top cover and the casing. Top welding, because the welding position is on a plane, requires very high standards for the insertion and positioning of the cover plate into the casing; otherwise, welding problems at the four corners are likely to occur. Furthermore, top welding requires a high degree of automation in the equipment.

[0004] Therefore, there is an urgent need for a packaging structure and method that can avoid the aforementioned problems in the welding process. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a battery cell housing and its manufacturing method, which can avoid the problems of welding process, reduce the requirements for the fit between the housing and the cover, simplify the structure, reduce equipment investment, and reduce costs.

[0006] To achieve the above objectives, this disclosure provides a battery cell housing, including a housing and a cover. The housing has a first rolled edge formed on its circumferential edge, and the cover has a second rolled edge formed on its circumferential edge. The first rolled edge and the second rolled edge are stacked on top of each other and wound together to form a rolled edge structure.

[0007] The first rolled edge and the second rolled edge are bent to form a pleated structure, which is located between the rolled edge structure and the circumferential edge of the shell and the cover.

[0008] Optionally, the pleated structure includes at least one bent protrusion, which is formed by bending a first rolled edge and a second rolled edge, both of which are planar, in the same direction.

[0009] Optionally, the portions of the first rolled edge and the second rolled edge that constitute the bent protrusion are completely fitted together.

[0010] Optionally, the portion of the first rolled edge that forms the bent protrusion is a first part, and the portion of the second rolled edge that forms the bent protrusion is a second part, wherein the second part has an adhering part and a pleated part, the adhering part adhering to the first part; and the pleated part bending away from the first part.

[0011] Optionally, the first part includes a planar portion parallel to the plane containing the first and second rolled edges, and a vertical portion perpendicular to the plane containing the first and second rolled edges.

[0012] The fitting portion is fitted to the planar portion;

[0013] The pleated portion is provided corresponding to the vertical portion, and protrudes relative to the vertical portion in a direction parallel to the plane containing the first and second rolled edges, which are planar.

[0014] Optionally, the rolled edge structure is formed by rolling a first rolled edge and a second rolled edge that are in a planar shape, and the rolled edge structure is superimposed on the unrolled portions of the first rolled edge and the second rolled edge that are in a planar shape; the portion of the rolled edge that constitutes the rolled edge structure is a third portion, and the portion of the second rolled edge that constitutes the rolled edge structure is a fourth portion, wherein...

[0015] The third part includes a stacked portion and an extension portion, wherein the stacked portion overlaps with the fourth part; the extension portion bends from the outer peripheral edge of the stacked portion and extends to the side of the fourth part opposite to the stacked portion, and overlaps with the fourth part.

[0016] Optionally, a sealing layer is provided between the two overlapping surfaces of the third and fourth parts.

[0017] As another technical solution, the present invention also provides a method for manufacturing a battery cell casing, comprising:

[0018] A housing and a cover are provided, wherein the circumferential edge of the housing is formed with a first rolled edge and the circumferential edge of the cover is formed with a second rolled edge, the first rolled edge and the second rolled edge are planar and overlap each other;

[0019] The first rolled edge and the second rolled edge are rolled together to form a rolled edge structure;

[0020] The first rolled edge and the second rolled edge are bent to form a pleated structure, which is located between the rolled edge structure and the circumferential edge of the shell and the cover.

[0021] Optionally, in the provided housing and cover, the outer peripheral edge of the first rolled edge is formed with an extension, the extension being perpendicular to each other with respect to the planar first rolled edge and the second rolled edge;

[0022] The step of winding the first rolled edge and the second rolled edge to form a rolled edge structure includes:

[0023] The extension is bent so that it overlaps the side of the second rolled edge opposite to the first rolled edge;

[0024] The overlapping extensions, the first rolled edge, and the second rolled edge are bent toward the side where the extensions are located to form an arc-shaped portion at the circumferential edge of the overlapping extensions, the first rolled edge, and the second rolled edge.

[0025] The extension forming the arc portion, a portion of the first rolled edge and the second rolled edge are wound toward the side where the extension portion is located, and the arc portion is flattened during the winding process, so that the extension portion, a portion of the first rolled edge and the second rolled edge overlap the unwound portion of the planar first rolled edge and the second rolled edge.

[0026] Optionally, the pleated structure includes at least one bent protrusion;

[0027] In the provided housing and cover, the second rolled edge has a fitting portion and a pleated portion constituting the bent protrusion;

[0028] The step of bending the first rolled edge and the second rolled edge to form a pleated structure includes:

[0029] The first rolled edge is bent toward the direction of the bonding portion, and the portion of the first rolled edge that forms the bent protrusion is bonded to the bonding portion;

[0030] The pleated portion protrudes in a direction away from the portion that forms the bent protrusion after the first rolled edge.

[0031] The present invention has the following beneficial effects:

[0032] In the technical solution of the battery cell housing and its manufacturing method provided by the present invention, a first rolled edge is formed on the circumferential edge of the housing, and a second rolled edge is formed on the circumferential edge of the cover. The first and second rolled edges are stacked on top of each other and wound together to form a rolled edge structure. This rolled edge structure can seal and join the circumferential edges of the housing and the cover together, thereby replacing the welding process in the prior art, avoiding the problems of the welding process, reducing the fitting requirements of the housing and the cover, simplifying the structure, reducing equipment investment, and lowering costs. On this basis, the first and second rolled edges are bent to form a pleated structure. This pleated structure is located between the rolled edge structure and the circumferential edges of the housing and the cover. By using this pleated structure in combination with the above-mentioned rolled edge structure, the sealing performance of the housing and the cover can be further improved, and it is also beneficial to the cell's breathing expansion, thereby improving the packaging reliability. Attached Figure Description

[0033] Figure 1 This is a partial cross-sectional view of the battery cell casing provided in an embodiment of the present invention;

[0034] Figure 2 for Figure 1 Enlarged view of the rolled edge and pleated structure in the image;

[0035] Figure 3 for Figure 1 A partial cross-sectional view of the battery cell casing before the formation of the rolled edge and pleated structures;

[0036] Figure 4 Another partial cross-sectional view of the battery cell housing provided in an embodiment of the present invention;

[0037] Figure 5 for Figure 4 Enlarged view of the rolled edge and pleated structure in the image;

[0038] Figure 6 for Figure 4 A partial cross-sectional view of the battery cell casing before the formation of the rolled edge and pleated structures;

[0039] Figure 7A In order to be in Figure 2 An enlarged view showing the addition of a sealing layer to the existing rolled edge structure;

[0040] Figure 7B In order to be in Figure 5 An enlarged view showing the addition of a sealing layer to the existing rolled edge structure;

[0041] Figure 8 for Figure 7A or Figure 7B A partial cross-sectional view of the battery cell casing before the formation of the rolled edge and pleated structures;

[0042] Figure 9AA partial cross-sectional view of the battery cell housing at the completion of step S101 in the manufacturing method of the battery cell housing provided in the embodiment of the present invention;

[0043] Figure 9B A partial cross-sectional view of the battery cell casing at step S102 in the manufacturing method of the battery cell casing provided in the embodiment of the present invention;

[0044] Figure 9C A partial cross-sectional view of the battery cell housing at step S103 in the manufacturing method of the battery cell housing provided in the embodiment of the present invention;

[0045] Figure 9D A partial cross-sectional view of the battery cell housing at step S104 in the manufacturing method of the battery cell housing provided in the embodiment of the present invention;

[0046] Figure 9E A partial cross-sectional view of the battery cell casing at step S105 in the manufacturing method of the battery cell casing provided in the embodiment of the present invention;

[0047] Figure 9F A partial cross-sectional view of the battery cell housing at step S106 in the manufacturing method of the battery cell housing provided in the embodiment of the present invention;

[0048] Figure 9G A partial cross-sectional view of the battery cell casing at step S107 in the manufacturing method of the battery cell casing provided in the embodiment of the present invention;

[0049] Figure 9H This is a partial cross-sectional view of the battery cell housing after step S108 is completed in the battery cell housing manufacturing method provided in this embodiment of the invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] The shapes and sizes of the components in the accompanying drawings do not reflect actual proportions and are intended only to facilitate understanding of the embodiments of the present invention.

[0052] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0053] This disclosure is not limited to the embodiments shown in the accompanying drawings, but includes modifications to the configuration based on the manufacturing process. Therefore, the areas illustrated in the drawings are schematic, and the shapes of the areas shown illustrate specific shapes of the areas of an element, but are not intended to be limiting.

[0054] Please see Figure 1 The battery cell housing provided in this embodiment of the invention includes a housing 1 and a cover 2. The circumferential edge of the housing 1 has a first rolled edge 11, and the circumferential edge of the cover 2 has a second rolled edge 21. The first rolled edge 11 and the second rolled edge 21 are stacked together and wound to form a rolled edge structure 3. This rolled edge structure 3 can seal and join the circumferential edges of the housing 1 and the cover 2 together, thereby replacing the welding process in the prior art, avoiding problems associated with welding, reducing the requirements for the fit between the housing and the cover, simplifying the structure, reducing equipment investment, and lowering costs. The first rolled edge 11 and the second rolled edge 21 are bent to form a pleated structure 4, which is located between the rolled edge structure 3 and the circumferential edges of the housing 1 and the cover 2. By combining this pleated structure 4 with the rolled edge structure 3, the sealing performance between the housing 1 and the cover 2 can be further improved, and the cell's breathing expansion can be facilitated, thereby improving packaging reliability.

[0055] Specifically, the housing 1 is, for example, a square housing, a rectangular housing, etc., and one end of the housing 1 has an opening for inserting the battery cell. The cover 2 is, for example, a cover plate, which can close the opening when it is engaged with the housing 1, so as to form a sealed space for accommodating the battery cell together with the housing 1.

[0056] In some alternative embodiments, such as Figure 3As shown, the first rolled edge 11 and the second rolled edge 21 are flattened, i.e., planar, before the formation of the rolled edge structure 3 and the pleated structure 4. Optionally, before the formation of the rolled edge structure 3 and the pleated structure 4, the planes containing the first rolled edge 11 and the second rolled edge 21 are perpendicular to the opening orientation of the housing 1, for example, Figure 3 The opening of the shell 1 is parallel to the Y direction and faces upwards; the plane containing the first rolled edge 11 and the second rolled edge 21, which are planar, is perpendicular to the Y direction and parallel to the X direction. Of course, in practical applications, depending on specific needs, the angle between the plane containing the first rolled edge 11 and the second rolled edge 21 and the opening direction of the shell 1 can be any angle other than 90°, and this embodiment of the invention does not impose any particular limitation on this. It should be noted that in practical applications, the first rolled edge 11 and the second rolled edge 21 can also be non-planar, such as arc-shaped, before forming the above-mentioned rolled edge structure 3 and pleated structure 4, as long as the above-mentioned rolled edge structure and pleated structure can be formed by winding and bending; this embodiment of the invention does not impose any particular limitation on this.

[0057] In some alternative embodiments, such as Figure 2 As shown, the pleated structure 4 includes at least one bent protrusion. Figure 2 A bent protrusion is shown, which is formed by bending a first rolled edge 11 and a second rolled edge 21, both of which are flat, in the same direction. Figure 2 The bending protrusion shown is formed by bending a first rolled edge 11 and a second rolled edge 21, both of which are planar, upwards. This bending protrusion not only extends the gap between the cover 2 and the housing 1, but also creates a labyrinthine gap, further improving the sealing between the housing 1 and the cover 2. It also facilitates the cell's breathing expansion, thereby improving packaging reliability. Furthermore, the bending protrusion has a simple structure and is easy to manufacture.

[0058] In some alternative embodiments, such as Figure 2 As shown, the portions (114, 213) forming the aforementioned bent protrusions, namely, are completely fitted together, that is, they are combined. Figure 3 It can be seen that the portions (114, 213) forming the bending protrusions of the first roll 11 and the second roll 21 remain overlapping each other before and after bending. However, the embodiments of the present invention are not limited to this. In some alternative embodiments, the portions forming the bending protrusions of the first roll 11 and the second roll 21 may not be completely fitted together. For example, please refer to [further details omitted]. Figure 4 and Figure 5The portion of the first rolled edge 11 that forms the bent protrusion is the first part 114, and the portion of the second rolled edge that forms the bent protrusion is the second part 213'. The second part 213' has a fitting portion 213a and a pleated portion 213b. The fitting portion 213a fits into the first part 114; the pleated portion 213b bends away from the first part 114. This pleated portion 213b facilitates cell breathing and expansion, thereby further improving packaging reliability.

[0059] The structure of the aforementioned pleated portion 213b can be varied. For example, the first part 114 includes a planar portion 114a parallel to the plane containing the first and second rolled edges 11 and 21, and a vertical portion 114b perpendicular to the plane containing the first and second rolled edges. That is, the planar portion 114a is parallel to the X direction, and the vertical portion 114b is parallel to the Y direction. The aforementioned fitting portion 213a fits into the planar portion 114a. The pleated portion 213b is correspondingly provided with the vertical portion 114b, and protrudes relative to the vertical portion 114b in a direction parallel to the plane containing the first and second rolled edges 11 and 21, that is, in a direction parallel to the X direction and in a direction away from the vertical portion 114b. Figure 5 The left side protrudes. In this way, while achieving the effect of cell breathing and expansion, the folded part 213b is flush with the surface of the cover 2 that is away from the shell, and no protrusion is produced on the outer contour of the cover.

[0060] In some alternative embodiments, such as Figure 2 and Figure 5 As shown, the aforementioned bent protrusion is a single portion, and it protrudes in the same direction as the opening of the housing 1 relative to the unbent portions (111, 211) of the planar first rolled edge 11 and the second rolled edge 21. For example, as... Figure 5 As shown, the opening of the housing 1 is parallel to the Y direction and faces upward; the aforementioned bent protrusion protrudes upward in a direction parallel to the Y direction. Of course, this embodiment of the invention is not limited to this. In practical applications, the bent protrusion may also protrude in the opposite direction to the opening of the housing 1. There may also be multiple bent protrusions, and the protruding directions of the multiple bent protrusions may be the same or different. For example, multiple bent protrusions may form a wavy pleated structure.

[0061] In some alternative embodiments, the longitudinal cross-sectional shape of the aforementioned bent protrusion is, for example, rectangular, square, arc-shaped, trapezoidal, etc. For example, Figure 2 and Figure 5 The longitudinal cross-sectional shape of the bending protrusion is rectangular, and optionally, the corners of the bending protrusion are rounded.

[0062] In some alternative embodiments, such as Figure 2 and Figure 5 As shown, the rolled edge structure 3 is formed by rolling a first rolled edge 11 and a second rolled edge 21 that are in a planar shape, and the rolled edge structure 3 is superimposed on the unrolled portions (111, 211) of the first rolled edge 11 and the second rolled edge 21 that are in a planar shape. That is, the first rolled edge 11 and the second rolled edge 21 are in a flat state before forming the above-mentioned rolled edge structure 4, that is, in a planar shape. Figure 3 and Figure 6 The first rolled edge 11 and the second rolled edge 21 are shown in their respective states. The edge portions of the planar first rolled edge 11 and the second rolled edge 21 near their outer peripheral edges are rolled to form the rolled edge structure 3 described above, while the remaining portions are not rolled and remain planar. Based on this, the edge portions are overlapped on the unrolled portions (111, 211) after being rolled. This improves the sealing effect. Optionally, the rolled edge structure 3 is overlapped on the side of the unrolled portions (111, 211) adjacent to the second rolled edge 21, that is, Figure 2 and Figure 5 The upper side of the second rolled edge 21. Of course, in practical applications, depending on specific needs, it can also be rolled in the same or opposite direction, so that the rolled edge structure is superimposed on the side of the unrolled portion adjacent to the first rolled edge. Alternatively, the plane of the planar unrolled portion (111, 211) is perpendicular to the opening orientation of the housing 1.

[0063] Based on this, such as Figure 2 and Figure 5 As shown, the portion of the first rolled edge 11 that constitutes the rolled edge structure 3 is the third part, and the portion of the second rolled edge 21 that constitutes the rolled edge structure 3 is the fourth part 212. The third part includes a stacked portion 112 and an extension portion 113, wherein the stacked portion 112 overlaps with the fourth part 212; the extension portion 113 bends from the outer peripheral edge of the stacked portion 112 and extends to the side of the fourth part 212 opposite to the stacked portion 112, and overlaps with the fourth part 212. Specifically, the first rolled edge 11 extends a portion relative to the outer peripheral edge of the second rolled edge 21, and this portion is the aforementioned extension portion 113. Optionally, as... Figure 3 and Figure 6 As shown, the extension 113' before winding is parallel to (or at an obtuse angle greater than 90°) the opening of the housing 1, so as to facilitate the installation of the cover 2. With the help of this extension 113, the outer peripheral edge of the fourth part 212 can be covered, thereby sealing the gap between the first rolled edge 11 and the second rolled edge 21 to isolate it from the outside.

[0064] In some alternative embodiments, such as Figure 7A and Figure 7BAs shown, a sealing layer 5 is provided between the two overlapping surfaces of the third part (including the overlapping portion 112 and the extension portion 113) and the fourth part 212. This sealing layer 5 is made of, for example, sealant or other sealing materials. The sealing layer 5 further enhances the pressure resistance and airtightness of the rolled edge structure 3. Optionally, the structure of the sealing layer 5' before winding is as follows: Figure 8 As shown, it can be attached to the surface of the extension 113' and the stacked portion 112' adjacent to the side of the cover 2 before winding.

[0065] As another technical solution, embodiments of the present invention also provide a method for manufacturing a battery cell casing, in order to manufacture... Figures 1 to 3 As shown, or Figures 4 to 6 Taking the battery cell casing shown as an example, the method includes:

[0066] S1. Provide a shell 1 and a cover 2. The circumferential edge of the shell 1 is formed with a first rolled edge 11, and the circumferential edge of the cover 2 is formed with a second rolled edge 21. The first rolled edge 11 and the second rolled edge 21 are planar and overlap each other.

[0067] The first rolled edge 11 and the second rolled edge 21 are flattened, i.e., planar, before the formation of the rolled edge structure 3 and the pleated structure 4, as shown below. Figure 3 and Figure 6 As shown. Optionally, before forming the above-mentioned rolled edge structure 3 and pleated structure 4, the planes containing the first rolled edge 11 and the second rolled edge 21 are both perpendicular to the opening orientation of the shell. Of course, in practical applications, depending on specific needs, the angle between the planes containing the first rolled edge 11 and the second rolled edge 21 and the opening orientation of the shell 1 can also be other than 90°, and the embodiments of the present invention do not have any particular limitations in this regard. It should be noted that in practical applications, the first rolled edge 11 and the second rolled edge 21 can also be non-planar, such as arc-shaped, before forming the above-mentioned rolled edge structure 3 and pleated structure 4, as long as the above-mentioned rolled edge structure and pleated structure can be formed by rolling and bending, and the embodiments of the present invention do not have any particular limitations in this regard.

[0068] S2. The first rolled edge 11 and the second rolled edge 21 are rolled together to form a rolled edge structure 3;

[0069] S3. The first rolled edge 11 and the second rolled edge 21 are bent to form a pleated structure 4, which is located between the rolled edge structure 3 and the circumferential edges of the shell 1 and the cover 2.

[0070] In step S1 above, if Figure 3 and Figure 6 As shown, the outer peripheral edge of the first rolled edge 11 has an extension 113, which is perpendicular to the planar first rolled edge 11 and the second rolled edge 21. Based on this, step S2 specifically includes:

[0071] S21, bend the extension (i.e., the extension 113' before winding) so that it overlaps the side of the second rolled edge 21 away from the first rolled edge 11.

[0072] S22. The overlapping extensions (i.e., the extensions 113' before winding), the first rolled edge 11 and the second rolled edge 21 are bent toward the side where the extensions are located, so as to form an arc-shaped portion at the circumferential edge of the overlapping extensions (i.e., the extensions 113' before winding), the first rolled edge 11 and the second rolled edge 21.

[0073] By means of the aforementioned arc portion, the second rolled edge 21 can be restricted between the overlapping extension portion (i.e., the extension portion 113' before winding) and the first rolled edge 11, thereby preventing the second rolled edge 21 from moving relative to the extension portion and the first rolled edge 11, thus limiting the cover 2 and preventing the cover 2 from moving during winding.

[0074] S23. The extension portion forming the arc portion (i.e., the extension portion 113' before winding), a portion of the first rolled edge 11 and the second rolled edge 21 are wound toward the side where the extension portion is located, and the arc portion is flattened during the winding process, so that the extension portion (i.e., the extension portion 113' before winding), a portion of the first rolled edge 11 and the second rolled edge 21 are superimposed on the unwound portions (111, 211) of the first rolled edge and the second rolled edge which are in a planar shape.

[0075] Specifically, the first rolled edge 11 and the second rolled edge 21 are flattened, i.e., planar, before forming the rolled edge structure 3. The edge portions of the planar first rolled edge 11 and the second rolled edge 21 near their outer peripheral edges are rolled to form the rolled edge structure 3, while the remaining portions are not rolled and remain planar. Based on this, the edge portions are overlapped on the unrolled portions (111, 211) after rolling. This improves the sealing effect. Optionally, the rolled edge structure 3 is overlapped on the side of the unrolled portions (111, 211) adjacent to the second rolled edge 21, i.e. Figure 2 and Figure 5 The upper side of the second rolled edge 21. Of course, in practical applications, depending on specific needs, it can also be rolled in the same or opposite direction, so that the rolled edge structure is superimposed on the side of the unrolled portion adjacent to the first rolled edge. Alternatively, the plane of the planar unrolled portion is perpendicular to the opening orientation of the housing.

[0076] The portion of the first rolled edge 11 that forms the rolled edge structure 3 is the third part, and the portion of the second rolled edge 21 that forms the rolled edge structure 3 is the fourth part 212. The third part includes a stacked portion 112 and an extension portion 113. The stacked portion 112 overlaps with the fourth part 212. The extension portion 113 bends from the outer peripheral edge of the stacked portion 112 and extends to the side of the fourth part 212 opposite to the stacked portion 112, overlapping with the fourth part 212. Specifically, the first rolled edge 11 extends a portion relative to the outer peripheral edge of the second rolled edge 21; this portion is the aforementioned extension portion 113. Optionally, the extension portion 113' before rolling is parallel to the opening orientation of the housing 1 to facilitate the installation of the cover 2. With the help of this extension portion 113, the outer peripheral edge of the fourth part 212 can be covered, thereby sealing the gap between the first rolled edge 11 and the second rolled edge 21 to isolate it from the outside.

[0077] In step S21 above, the extension portion (i.e., the extension portion 113' before winding) is bent so that it is stacked on the side of the second rolled edge 21 away from the first rolled edge 11 (i.e., the side of the fourth part 212 away from the stacked part 112); in step S22 above, the extension portion (i.e., the extension portion 113' before winding), the stacked part 112 and the fourth part 212 located between them are bent toward the side where the extension portion is located to form an arc portion. The arc portion is curved upward relative to the unbent part of the extension portion (i.e., the extension portion 113' before winding). This is beneficial for stacking the extension portion 113, the stacked part 112 and the fourth part 212 located between them onto the unwound part (111, 211) of the first rolled edge 11 and the second rolled edge 21 in a planar manner in the subsequent step S23 by flattening.

[0078] In some alternative embodiments, such as Figure 5 As shown, the pleated structure 4 includes at least one bent protrusion. Based on this, in step S1 above, the portion of the first rolled edge 11 that forms the bent protrusion is the first portion 114, and the portion of the second rolled edge that forms the bent protrusion is the second portion 213', wherein the second portion 213' has a fitting portion 213a and a pleated portion 213b. The fitting portion 213a fits against the horizontal portion 114a of the first portion 114; the pleated portion 213b bends away from the vertical portion 114b of the first portion 114. This pleated portion 213b facilitates cell breathing expansion, thereby further improving packaging reliability.

[0079] It is easy to understand that the fitting portion 213a and the pleated portion 213b of the second rolled edge 21 are pre-made during the processing of the cover. In the subsequent step S3, only the first rolled edge 11 needs to be bent to finally form the pleated structure 3. Specifically, the above step S3 includes:

[0080] The first rolled edge 11 is bent toward the direction of the aforementioned fitting portion 213a, and the portion of the first rolled edge 11 that forms the bent protrusion (i.e., the horizontal portion 114a of the aforementioned first portion 114) is fitted with the fitting portion 213a.

[0081] The pleated portion 213b protrudes in a direction away from the portion that bends away from the first rolled edge 11 to form the bent protrusion (i.e., the vertical portion 114b of the first portion 114 mentioned above). In this way, while achieving the effect of cell breathing expansion, the pleated portion is flush with the surface of the cover away from the shell, and no protrusion is generated on the outer contour of the cover.

[0082] In one specific embodiment, please refer to the following: Figures 9A to 9H The method for manufacturing a battery cell casing provided in this embodiment of the invention includes:

[0083] S101, such as Figure 9A As shown, the cover 2 is placed on the side where the opening of the housing 1 is located to close the opening, and the second rolled edge 21 of the cover 2, which is flat, is stacked on the first rolled edge 11 of the housing 1, which is flat.

[0084] The first rolled edge 11 extends a portion relative to the outer peripheral edge of the second rolled edge 21. This portion is the extension 113' before winding. The extension 113' before winding is parallel to (or at an obtuse angle greater than 90°) the opening of the housing 1, so as to facilitate the installation of the cover 2.

[0085] S102, such as Figure 9B As shown, the aforementioned extension (i.e., the extension 113' before winding) is bent toward the direction close to the second rolled edge 21 and flattened so that it can be stacked on the side of the second rolled edge 21 opposite to the first rolled edge 11.

[0086] S103, such as Figure 9C As shown, the overlapping extensions (i.e., the extension 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding), and the second rolled edge (i.e., the fourth portion 212' before winding) are bent toward the side where the extensions are located, so as to form an arc portion S at the circumferential edge of the overlapping extensions (i.e., the extension 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding), and the second rolled edge (i.e., the fourth portion 212' before winding).

[0087] By means of the aforementioned arc portion S, the second rolled edge 21 can be restricted between the overlapping extension portions (i.e., the extension portion 113' before winding) and the first rolled edge 11, thus preventing the second rolled edge 21 from moving relative to the extension portion and the first rolled edge 11, thereby limiting the cover 2 and preventing the cover 2 from moving during winding.

[0088] S104, such as Figure 9D As shown, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding), and the second rolled edge (i.e., the fourth portion 212' before winding) are bent at a certain angle (e.g., bent at 30° to 45°) toward the side where the extension portion is located.

[0089] S105, such as Figure 9E As shown, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding) and the second rolled edge (i.e., the fourth portion 212' before winding) are bent at approximately 90° toward the side where the extension portion is located.

[0090] S106, such as Figure 9F As shown, the extension portion forming the arc portion S (i.e., the extension portion 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding) and the second rolled edge (i.e., the fourth portion 212' before winding) are bent to 90° towards the side where the extension portion is located.

[0091] S107, such as Figure 9G and Figure 9H As shown, the extension portion (i.e., the extension portion 113' before winding), the first rolled edge (i.e., the overlapping portion 112' before winding), and the second rolled edge (i.e., the fourth portion 212' before winding) of the arc portion S are pressed down and flattened. At this time, the arc portion S becomes a planar shape, and a rolled edge structure 3 (including the extension portion 113, the overlapping portion 112, and the fourth portion 212) is formed on the unwound portions (111, 211) of the first rolled edge 11 and the second rolled edge 21 which are in a planar shape.

[0092] S108, such as Figure 9H As shown, the first rolled edge 11 and the second rolled edge 21 are bent to form a pleated structure 4.

[0093] In the technical solution of the battery cell housing and its manufacturing method provided in this invention, a first rolled edge is formed on the circumferential edge of the housing, and a second rolled edge is formed on the circumferential edge of the cover. The first and second rolled edges are stacked on top of each other and wound together to form a rolled edge structure. This rolled edge structure can seal and join the circumferential edges of the housing and the cover together, thereby replacing the welding process in the prior art, avoiding the problems that occur in the welding process, reducing the fitting requirements of the housing and the cover, simplifying the structure, reducing equipment investment, and lowering costs. On this basis, the first and second rolled edges are bent to form a pleated structure. This pleated structure is located between the rolled edge structure and the circumferential edges of the housing and the cover. By using this pleated structure in combination with the above-mentioned rolled edge structure, the sealing performance of the housing and the cover can be further improved, and it is also beneficial to the cell's breathing expansion, thereby improving the packaging reliability.

[0094] It should be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A battery cell housing, characterized in that, The device includes a shell and a cover. The shell has a first rolled edge on its circumferential edge, and the cover has a second rolled edge on its circumferential edge. The first rolled edge and the second rolled edge are stacked on top of each other and rolled together to form a rolled edge structure. The first and second rolled edges are bent to form a pleated structure, which is located between the rolled edge structure and the circumferential edges of the shell and the cover. The pleated structure includes at least one bent protrusion, which is formed by bending the planar first and second rolled edges in the same direction. The portion of the first rolled edge forming the bent protrusion is a first part, and the portion of the second rolled edge forming the bent protrusion is a second part. The second part has a fitting part and a pleated part. The fitting part fits into the first part. The pleated part is bent away from the first part. The first part includes a planar part parallel to the plane where the planar first and second rolled edges are located, and a vertical part perpendicular to the plane where the planar first and second rolled edges are located. The fitting portion is fitted to the planar portion; The pleated portion is provided corresponding to the vertical portion, and protrudes relative to the vertical portion in a direction parallel to the plane containing the first and second rolled edges, which are planar.

2. The cell housing according to claim 1, characterized in that, The rolled edge structure is formed by rolling a first rolled edge and a second rolled edge that are in a planar shape, and the rolled edge structure overlaps the unrolled portions of the first rolled edge and the second rolled edge that are in a planar shape; the portion of the rolled edge that constitutes the rolled edge structure is the third portion, and the portion of the rolled edge that constitutes the rolled edge structure is the fourth portion, wherein... The third part includes a stacked portion and an extension portion, wherein the stacked portion overlaps with the fourth part; the extension portion bends from the outer peripheral edge of the stacked portion and extends to the side of the fourth part opposite to the stacked portion, and overlaps with the fourth part.

3. The cell housing according to claim 2, characterized in that, A sealing layer is provided between the two surfaces of the third part and the fourth part that are stacked on each other.

4. A method for manufacturing a battery cell casing according to any one of claims 1 to 3, characterized in that, include: A housing and a cover are provided, wherein the circumferential edge of the housing is formed with a first rolled edge and the circumferential edge of the cover is formed with a second rolled edge, the first rolled edge and the second rolled edge are planar and overlap each other; The first rolled edge and the second rolled edge are rolled together to form a rolled edge structure; The first rolled edge and the second rolled edge are bent to form a pleated structure, which is located between the rolled edge structure and the circumferential edge of the shell and the cover.

5. The method for manufacturing the cell casing according to claim 4, characterized in that, In the provided housing and cover, the outer peripheral edge of the first rolled edge is formed with an extension, which is perpendicular to the first rolled edge and the second rolled edge, which are planar. The step of winding the first rolled edge and the second rolled edge to form a rolled edge structure includes: The extension is bent so that it overlaps the side of the second rolled edge opposite to the first rolled edge; The overlapping extensions, the first rolled edge, and the second rolled edge are bent toward the side where the extensions are located to form an arc-shaped portion at the circumferential edge of the overlapping extensions, the first rolled edge, and the second rolled edge. The extension forming the arc portion, a portion of the first rolled edge and the second rolled edge are wound toward the side where the extension portion is located, and the arc portion is flattened during the winding process, so that the extension portion, a portion of the first rolled edge and the second rolled edge overlap the unwound portion of the planar first rolled edge and the second rolled edge.

6. The method for manufacturing a battery cell casing according to claim 5, characterized in that, The pleated structure includes at least one bent protrusion; In the provided housing and cover, the second rolled edge has a fitting portion and a pleated portion constituting the bent protrusion; The step of bending the first rolled edge and the second rolled edge to form a pleated structure includes: The first rolled edge is bent toward the direction of the bonding portion, and the portion of the first rolled edge that forms the bent protrusion is bonded to the bonding portion; The pleated portion protrudes in a direction away from the portion that forms the bent protrusion after the first rolled edge.

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