Soft package battery cell and battery module

Abstract

The utility model provides a soft package battery cell and a battery module. The soft package battery cell comprises a naked battery cell, the soft coating film comprises two half films which are respectively arranged on two opposite sides of the naked battery cell, and each half film comprises a first film surface close to the naked battery cell; at least one half film is provided with a pit, and the two half films are connected in a hot melting manner, so that the pit forms an accommodating cavity for accommodating a naked battery cell; the pit comprises two side faces and a bottom face connected with the two side faces. The first film surface comprises an outer edge sub-surface surrounding the pit; the edge, close to the outer edge sub-face, of the side face is aligned with the edge, close to the bottom face, of the side face in the third direction. According to the soft package battery cell and the battery module provided by the invention, the side surface of the pit is perpendicular to the stacked pole pieces of the bare battery cell. Therefore, after the half film is stamped, the pit with larger depth and larger bottom surface size can be formed, and a naked battery cell with larger size can be accommodated.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a pouch cell and battery module. Background Technology

[0002] Pouch batteries are widely used in mobile phones, wearable electronics, laptops, power tools, and electric vehicles due to their advantages such as good safety performance, light weight, large capacity, and flexible design. The battery cell of a pouch battery, also known as a pouch cell, includes the bare cell and the soft-pack film covering it.

[0003] When packaging bare battery cells, recesses need to be punched into the film of the pouch cell to hold the bare cell. However, the maximum depth of the recesses limits the thickness design of the bare cell, which in turn hinders the improvement of the energy density of the pouch cell. Utility Model Content

[0004] In view of this, the purpose of this application is to propose a pouch cell and battery module to at least partially solve the problem that the limited depth of the pits in the pouch film restricts the thickness design of the bare cell.

[0005] Based on the above objectives, a first aspect of this application provides a pouch cell, comprising: a bare cell, the bare cell including a cell body, wherein at least one end of the cell body along a first direction has a tab; a pouch film including two half-films respectively disposed on opposite sides of the bare cell, the half-film including a first film surface close to the bare cell; at least one of the half-films having a recess, the two half-films being thermally fused together to form a receiving cavity for accommodating the bare cell; wherein the recess includes two side surfaces disposed opposite to each other along a second direction, and a bottom surface connected to both side surfaces; the first film surface including an outer sub-surface surrounding the recess; the edge of the side surface near the outer sub-surface and the edge of the side surface near the bottom surface are aligned along a third direction; the first direction, the second direction, and the third direction are mutually perpendicular.

[0006] Optionally, a first bottom chamfer is provided between the bottom surface and the side surface; along the second direction, the battery cell body is located on the side closer to the bottom surface at the connection position between the first bottom chamfer and the bottom surface.

[0007] Optionally, the radius of the first bottom chamfer is R1, where 3mm ≤ R1 ≤ 4.5mm.

[0008] Optionally, a first top round chamfer is provided between the outer edge sub-face and the side surface, and the radius of the first top round chamfer is R2, where 2mm≤R2≤3mm.

[0009] Optionally, the semi-film includes a heat-sealing layer, a metal layer, and a protective layer sequentially stacked along a direction away from the bare battery cell; a first top rounded chamfer is provided between the outer sub-surface and the side surface, the thickness of the metal layer at the first bottom rounded chamfer is H1, the thickness of the metal layer at the first top rounded chamfer is H2, and the thickness of the metal layer at the outer sub-surface is H3.

[0010]

[0011] Optionally, the recess includes two side end faces disposed opposite each other along a first direction, and a gas storage space for storing gas is formed between the side end faces and the battery cell body; the edge of the side end face near the outer sub-surface is aligned with the edge of the side end face near the bottom surface along the third direction.

[0012] Optionally, a second bottom chamfer is provided between the side end face and the bottom surface, and along the first direction, the battery cell body is located on the side closer to the bottom surface at the connection position between the second bottom chamfer and the bottom surface.

[0013] Optionally, a second top round chamfer is provided between the side end face and the outer edge sub-face, and part of the pole lug is bent along the second top round chamfer.

[0014] Optionally, the maximum dimension of the pouch cell along the third direction is H, where H ≥ 12 mm.

[0015] Based on the same inventive concept, the second aspect of this application also provides a battery module, including the pouch cell as described in the first aspect.

[0016] As can be seen from the above, the soft-pack battery cell and battery module provided in this application have the edges of the side near the outer edge and the edges of the side near the bottom edge aligned along a third direction, which allows the sides of the recess to be perpendicular to the stacked electrode sheets in the battery cell body. This allows the half-film to form a recess with a relatively large actual depth after stamping, so that the recess can accommodate a thicker bare battery cell. At the same time, when the side is vertically arranged, the size of the bottom surface is closer to the size of the recess opening, which makes the surface size of the bottom surface along the second direction also increase accordingly, allowing the recess to accommodate a larger bare battery cell, thereby forming a soft-pack battery cell with a higher energy density. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a top view schematic diagram of a pouch cell according to an embodiment of this application;

[0019] Figure 2 for Figure 1 Schematic diagram of the cross section AA;

[0020] Figure 3 for Figure 1 Schematic diagram of the cross-section BB in the middle;

[0021] Figure 4 This is a three-dimensional schematic diagram of the half-film of the soft-pack battery cell according to an embodiment of this application;

[0022] Figure 5 for Figure 4 An enlarged schematic diagram of section C;

[0023] Figure 6 This is a cross-sectional schematic diagram of the half-film of the soft-pack battery cell according to an embodiment of this application;

[0024] Figure 7 This is a schematic diagram of the structure of the soft-pack film of the soft-pack battery cell according to an embodiment of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 100. Bare battery cell; 110. Battery cell body; 120. Electrode tab;

[0027] 200. Flexible membrane; 210. Half membrane; 211. First membrane surface; 2111. Outer edge sub-surface; 212. Recess; 2121. Side surface; 2122. Bottom surface; 2123. Side end face; 213. Receiving cavity; 214. First bottom chamfer; 215. First top chamfer; 216. Gas storage space; 217. Second bottom chamfer; 218. Second top chamfer; 220. Metal layer; 230. Heat-sealing layer; 240. Protective layer; 241. First protective sub-layer; 242. Second protective sub-layer; 250. Adhesive layer. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of this application.

[0030] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0031] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0032] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] Figure 1 A top-view schematic diagram of a pouch cell is shown. Figure 2 Showing Figure 1 A schematic diagram of the cross-section AA in the middle. Figure 3 Showing Figure 1 Schematic diagram of the cross section BB in the middle.

[0034] like Figure 1 and Figure 3 This application provides a pouch cell, including: a bare cell 100, the bare cell 100 including a cell body 110, the cell body 110 along a first direction (e.g., Figure 1 and Figure 3 At least one end of the bare cell 100 (in the X direction) is provided with a tab 120; the soft film 200 includes two half films 210 respectively disposed on opposite sides of the bare cell 100, the half film 210 including a first film surface 211 close to the bare cell 100; at least one half film 210 is provided with a pit 212, and the two half films 210 are thermally fused together so that the pit 212 forms a receiving cavity 213 for accommodating the bare cell 100.

[0035] Figure 4 A three-dimensional schematic diagram of the semi-membrane 210 is shown, such as... Figure 2 and Figure 4 The pit 212 includes along the second direction (e.g. Figure 4Two side surfaces 2121 (in the Y direction) are arranged opposite each other, and a bottom surface 2122 is connected to both side surfaces 2121; the first membrane surface 211 includes an outer edge sub-surface 2111 surrounding the recess 212, and the edge of the side surface 2121 near the outer edge sub-surface 2111 and the edge of the side surface 2121 near the bottom surface 2122 are arranged in a third direction (e.g., in the Y direction). Figure 2 and Figure 4 Aligned with the Z direction; the first, second, and third directions are mutually perpendicular.

[0036] For example, the bare cell 100 includes a positive electrode sheet, a negative electrode sheet, and a separator that isolates the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the negative electrode sheet, and the separator can form a cell body 110 with a wound structure or a stacked structure. A portion of the positive electrode sheet can extend out of the end of the cell body 110 to form a positive electrode tab, and a portion of the negative electrode sheet can extend out of the end of the cell body 110 to form a negative electrode tab. In the embodiments of this application, the tab 120 includes a positive electrode tab and a negative electrode tab.

[0037] For example, the positive tab and the negative tab can be disposed at the same end of the cell body 110; or, a positive tab is formed at one end of the cell body 110 and a negative tab is disposed at the opposite end.

[0038] For example, both half-films 210 may be provided with recesses 212. After the two half-films 210 are heat-fused together, the openings of the two recesses 212 face each other and are joined together to form a receiving cavity 213. Along a third direction, a portion of the bare cell 100 is located in one of the recesses 212 and another portion is located in the other recess 212.

[0039] For example, one half-membrane 210 is provided with a recess 212, and the other half-membrane 210 can be a flat membrane structure. After the two half-membranes 210 are heat-fused together, the flat half-membrane 210 covers the opening of the recess 212 of the other half-membrane 210 to form a receiving cavity 213.

[0040] For example, for the surface of the cell body 110 located between its two ends, the dimension along the first direction is the length of the surface, and the dimension perpendicular to the length is the width of the surface. The narrower surface of the cell body 110 is adjacent to the side surface 2121 of the recess 212, while the wider surface of the cell body 110 is in contact with the bottom surface 2122 of the recess 212.

[0041] For example, the outer edge sub-face 2111 is a frame-shaped surface surrounding the recess 212.

[0042] For example, the area where the outer edge sub-surface 2111 of the half-film 210 is located is the area that is not affected by stamping when stamping the indentation 212.

[0043] It should be noted that when the cell body 110 is a laminated structure, the third direction is perpendicular to the electrode plates (including positive electrode plates or negative electrode plates) in the laminated structure.

[0044] by Figure 2 Taking the structure and orientation shown as an example, the edge of side 2121 near the outer sub-surface 2111 is the upper edge of side 2121; the edge of side 2121 near the bottom surface 2122 is the lower edge of side 2121. The upper and lower edges of side 2121 are aligned along a third direction, meaning side 2121 is vertically positioned. At this time, side 2121 is perpendicular to the electrode in the cell body 110 of the laminated structure.

[0045] When the soft film 200 forms the pit 212, the stretching of the soft film 200 needs to be controlled within a preset range (the stretching of the soft film 200 is related to the thickness of the soft film 200). If the stretching of the soft film 200 exceeds the preset range, the soft film 200 may rupture.

[0046] In order to increase the depth of the recess 212 without changing the stretch of the soft film 200 (which can be understood as the surface width of the side 2121), this embodiment defines the structure of the side 2121 of the recess 212. It can be understood that, compared with other configurations, when the side 2121 is vertically configured, the actual depth of the resulting recess 212 is greater, which can accommodate a thicker bare battery cell 100.

[0047] In the pouch cell provided in this embodiment, the edge of the side surface 2121 near the outer sub-surface 2111 is aligned with the edge of the side surface 2121 near the bottom surface 2122 along a third direction, so that the side surface 2121 of the recess 212 is perpendicular to the stacked electrode sheets in the cell body 110. This allows the half-film 210 to form a recess 212 with a relatively large actual depth after stamping, so that the recess 212 can accommodate the bare cell 100 with a relatively large thickness, thereby forming a pouch cell with a high energy density.

[0048] Besides increasing the thickness of the bare cell 100 to improve the energy density of the pouch cell, increasing the area of ​​the positive and negative electrode plates of the bare cell 100 (i.e., the area of ​​the bare cell 100 perpendicular to the thickness direction) can also improve the energy density of the pouch cell. However, the area of ​​the positive and negative electrode plates of the bare cell 100 is limited by the size of the bottom surface 2122 of the recess 212.

[0049] Specifically, after the bare cell 100 is placed in the recess 212, it will fit against the bottom surface 2122. If the size of the bottom surface 2122 is smaller than the bare cell 100, interference will occur between the side surface 2121 of the recess 212 and the bare cell 100.

[0050] Still with Figure 2Taking the structure and orientation shown as an example, when the side 2121 is vertically arranged, the size of the bottom surface 2122 is closer to the opening size of the pit 212. This makes the surface size of the bottom surface 2122 along the second direction increase accordingly, which can make the area of ​​the bare cell 100 perpendicular to the thickness direction that the pit 212 can accommodate larger.

[0051] like Figure 2 In some embodiments, a first bottom chamfer 214 is provided between the bottom surface 2122 and the side surface 2121; along the second direction, the battery cell body 110 is located on the side closer to the bottom surface 2122 at the connection position between the first bottom chamfer 214 and the bottom surface 2122.

[0052] For example, the bottom surface 2122 can be a plane.

[0053] by Figure 2 The structure and orientation shown are used as examples for explanation. Figure 2 The first bottom chamfer 214 on the right side connects to the bottom surface 2122 at its lowest point. From this point to the right, the first bottom chamfer 214 gradually increases in height. The first bottom chamfer 214 connects to the side surface 2121 at its highest point. When the bare cell 100 is placed in the recess 212, the bottom surface of the cell body 110 abuts against the bottom surface 2122. Considering the foregoing, if the cell body 110 extends to the right beyond the connection point between the first bottom chamfer 214 and the bottom surface 2122, the gradually increasing first bottom chamfer 214 may interfere with the cell body 110.

[0054] To avoid the aforementioned situation, in this embodiment, the cell body 110 is positioned on the side closer to the bottom surface 2122 at the connection point between the first bottom chamfer 214 and the bottom surface 2122. When the bare cell 100 is placed in the recess 212, there is a sufficient gap between the cell body 110 and the side surface 2121, reducing the risk of interference between the soft-pack film 200 and the bare cell 100. This prevents the soft-pack film 200 from rupturing or the bare cell 100 from being squeezed together, thus helping to ensure the electrical performance of the soft-pack cell.

[0055] In some embodiments, the radius of the first bottom chamfer 214 is R1, where 3mm ≤ R1 ≤ 4.5mm.

[0056] For example, R1 can be 3mm, 3.5mm, 4mm or 4.5mm.

[0057] If R1 is too small, stress concentration will occur at the connection between the bottom surface 2122 and the side surface 2121 during the stamping process of the recess 212, which may lead to insufficient thickness of the soft film 200 at that location or even cracking. If R1 is too large, on the one hand, it will reduce the size of the bottom surface 2122 along the second direction, and on the other hand, it will also have a significant impact on the thickness of the soft film 200 at the connection between the bottom surface 2122 and the side surface 2121 (especially the thickness of the metal layer 220 inside the soft film 200).

[0058] To avoid the above problems, in this embodiment, R1 is limited to 3mm≤R1≤4.5mm, which can effectively disperse the internal stress at the connection position between the bottom surface 2122 and the side surface 2121, thereby preventing the soft film 200 at this position from cracking, and ensuring that the thickness of the soft film 200 at this position meets the process requirements, thereby improving the encapsulation protection effect of the soft film 200 on the bare cell 100.

[0059] Figure 5 Showing Figure 4 An enlarged diagram of section C. (See attached image.) Figure 2 and Figure 5 In some embodiments, a first top round chamfer 215 is provided between the outer edge sub-surface 2111 and the side surface 2121, and the radius of the first top round chamfer 215 is R2, 2mm≤R2≤3mm.

[0060] For example, R2 can be 2mm, 2.5mm or 3mm.

[0061] If R2 is too small, stress concentration will occur at the connection between the outer edge sub-face 2111 and the side surface 2121 during the stamping of the recess 212, which may lead to insufficient thickness of the soft coating 200 at that location or even cracking. If R2 is too large, it will have a significant impact on the thickness of the soft coating 200 at the connection between the outer edge sub-face 2111 and the side surface 2121 (especially the thickness of the metal layer 220 inside the soft coating 200).

[0062] To avoid the above problems, in this embodiment, R2 is limited to 2mm≤R2≤3mm, which can effectively disperse the internal stress at the connection position between the outer edge sub-surface 2111 and the side surface 2121, thereby preventing the soft film 200 at this position from cracking, and ensuring that the thickness of the soft film 200 at this position meets the process requirements, thereby improving the encapsulation protection effect of the soft film 200 on the bare cell 100.

[0063] Figure 6 A cross-sectional schematic diagram of the semi-membrane 210 is shown. (For example...) Figure 6In some embodiments, the semi-film 210 includes a heat-sealing layer 230, a metal layer 220, and a protective layer 240 sequentially stacked along a direction away from the bare cell 100; the thickness of the metal layer 220 at the first bottom chamfer 214 is H1, the thickness of the metal layer 220 at the first top chamfer 215 is H2, and the thickness of the metal layer 220 at the outer sub-surface 2111 is H3.

[0064] For example, the values ​​can be 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, or 0.58.

[0065] For example, Figure 7 A schematic diagram of the structure of a soft membrane 200 is shown, as follows: Figure 7 The protective layer 240 may include a first protective sublayer 241 and a second protective sublayer 242 stacked together. The first protective sublayer 241 is connected to the metal layer 220 through an adhesive layer 250, and the second protective sublayer 242 is connected to the first protective sublayer 241 through an adhesive layer 250.

[0066] For example, the metal layer 220 can be made of aluminum.

[0067] For example, the heat-sealing layer 230 may be made of at least one of polypropylene (PP) and polyethylene (PE).

[0068] For example, the first protective sublayer 241 can be made of nylon (PA), and the second protective sublayer 242 can be made of polyethylene terephthalate (PET).

[0069] When a pit 212 is formed on a half-film 210 including a metal layer 220, especially when the depth of the pit 212 is large, the thickness H1 of the metal layer 220 remaining at the first bottom chamfer 214 (the actual remaining thickness of the metal layer 220 after stamping) is correlated with the thickness H2 of the metal layer 220 remaining at the first top chamfer 215.

[0070] The applicant's research found that if... If the size limit is too small, achieving the required size may lead to greater difficulty in molding the 212-shaped indentation, resulting in a lower yield rate for the pouch cell, higher manufacturing costs, and hindering mass production. An excessively large thickness difference between H1 and H2 indicates that the thickness of H1 is too small. This could lead to cracking at the first bottom chamfer 214 of the pouch film 200, resulting in poor moisture barrier properties at that location and compromising the stability and safety of the pouch cell. Conversely, an excessively large thickness difference between H1 and H2 could also be due to an excessively large H2 thickness. This could cause wrinkles and bubbles to appear at the first top chamfer 215 of the pouch film 200, affecting the sealing performance of the pouch cell and negatively impacting its heat dissipation.

[0071] To avoid the above problems, this embodiment will Limited to This ensures that the soft-pack film 200 covering the bare battery cell 100 can achieve good sealing performance, ensuring that the soft-pack battery cell can undergo stable and safe charge and discharge cycles. It also helps to improve the yield of the soft-pack battery cell and reduce the manufacturing cost of the soft-pack battery cell.

[0072] It should also be noted that setting the side 2121 to be perpendicular to the electrode in the cell body 110 helps to increase the thickness of the residual metal layer 220 at the first bottom chamfer 214, which can further avoid the risk of the soft film 200 cracking at the first bottom chamfer 214, thus further improving the safety of the soft-pack cell.

[0073] like Figure 3 and Figure 4 In some embodiments, the recess 212 includes two side end faces 2123 disposed opposite to each other along a first direction, and a gas storage space 216 for storing gas is formed between the side end faces 2123 and the cell body 110; the edge of the side end face 2123 near the outer sub-surface 2111 is aligned with the edge of the side end face 2123 near the bottom surface 2122 along a third direction.

[0074] For example, the end of the cell body 110 is adjacent to the side end face 2123 of the recess 212.

[0075] For example, at least a portion of the tab 120 is located within the gas storage space 216.

[0076] For example, during the charge-discharge cycle of the bare cell 100, the cell body 110 generates gas, which can be stored in the gas storage space 216.

[0077] by Figure 3Taking the structure and orientation shown as an example, the edge of the side end face 2123 near the outer sub-surface 2111 is the upper edge of the side end face 2123; the edge of the side end face 2123 near the bottom surface 2122 is the lower edge of the side end face 2123. The upper and lower edges of the side end face 2123 are aligned along a third direction, that is, the side end face 2123 is vertically arranged. At this time, the side end face 2123 is perpendicular to the electrode in the cell body 110 of the laminated structure.

[0078] Similar to side surface 2121, when side surface 2123 is vertically arranged, the depth of recess 212 can be greater to accommodate the thicker bare cell 100. Simultaneously, the surface dimension of bottom surface 2122 along the first direction will also be larger, meaning the internal space of recess 212 will increase accordingly. When the bare cell 100 is placed in recess 212, a gap can exist between the cell body 110 and side surface 2123 (especially the portion of side surface 2123 near bottom surface 2122) to reduce the risk of interference between the soft coating 200 and the bare cell 100.

[0079] In addition, if there is a gap between the side end face 2123 and the cell body 110, the side end face 2123 can prevent the tab 120 from being squeezed when the two half-films 210 are heat-fused together, which can reduce the risk of the tab 120 breaking or other defects due to pressure.

[0080] like Figure 3 In some embodiments, a second bottom chamfer 217 is provided between the side end face 2123 and the bottom face 2122. Along the first direction, the battery cell body 110 is located on the side closer to the bottom face 2122 at the connection position between the second bottom chamfer 217 and the bottom face 2122.

[0081] For example, such as Figure 5 The radius of the second bottom chamfer 217 can be the same as or different from the radius of the first bottom chamfer 214.

[0082] by Figure 3 The structure and orientation shown are used as examples for explanation. Figure 3 The second bottom chamfer 217 on the right side connects to the bottom surface 2122 at its lowest point. From this point to the right, the second bottom chamfer 217 gradually increases in height. The second bottom chamfer 217 connects to the side end face 2123 at its highest point. When the bare cell 100 is placed in the recess 212, the bottom surface of the cell body 110 abuts against the bottom surface 2122. Considering the foregoing, if the cell body 110 extends to the right beyond the connection point between the second bottom chamfer 217 and the bottom surface 2122, the gradually increasing second bottom chamfer 217 may interfere with the cell body 110.

[0083] To avoid the above situation, in this embodiment, the battery cell body 110 is located on the side close to the bottom surface 2122 at the connection position between the second bottom chamfer 217 and the bottom surface 2122, so as to avoid interference between the bare battery cell 100 and the soft coating 200 due to the contact between the battery cell body 110 and the second bottom chamfer 217.

[0084] It should also be noted that setting the side end face 2123 to be perpendicular to the electrode in the cell body 110 helps to increase the thickness of the residual metal layer 220 at the second bottom chamfer 217, which can further avoid the risk of the soft film 200 cracking at the second bottom chamfer 217, thus further improving the safety of the soft-pack cell.

[0085] like Figure 3 In some embodiments, a second top round chamfer 218 is provided between the side end face 2123 and the outer edge sub-face 2111, and part of the tab 120 is bent along the second top round chamfer 218.

[0086] For example, such as Figure 5 The radius of the second chamfer 218 can be the same as or different from the radius of the first chamfer 215.

[0087] If the tab 120 needs to extend from the end of the cell body 110 near the bottom surface 2122 to above the outer edge surface 2111, when the two half-films 210 are heat-fused together, the half-film 210 at the connection position of the outer edge surface 2111 and the side end surface 2123 may squeeze the tab 120.

[0088] To avoid the aforementioned problems, this embodiment provides a second chamfer 218 between the side end face 2123 and the outer edge sub-face 2111. When the tab 120 extends to the upper edge of the side end face 2123, it can be bent along the second chamfer 218. In this way, when the two half-films 210 are heat-fused together, since the bending radius of the tab 120 is the same as the radius of the second chamfer 218, the pressure exerted by the half-film 210 on the tab 120 at the connection position between the outer edge sub-face 2111 and the side end face 2123 can be reduced, thus preventing the tab 120 from being damaged by pressure.

[0089] like Figure 2 In some embodiments, the maximum dimension of the pouch cell along a third direction is H, where H ≥ 12 mm.

[0090] For example, H can be 12mm, 14mm, 16mm, 20mm or 25mm.

[0091] In this embodiment, the side surface 2121 and side end surface 2123 of the recess 212 formed on the half-film 210 are both vertical surfaces perpendicular to the electrode in the cell body 110, which allows a larger space to be formed inside the recess 212. At the same time, limiting the radii of the first bottom chamfer 214, the first top chamfer 215, the second bottom chamfer 217, and the second top chamfer 218 can prevent stress concentration in the soft film 200 at the above-mentioned locations. Even if a deep recess 212 needs to be formed, the risk of the soft film 200 breaking can be guaranteed to be low. Even if the thickness of the cell body 110 is large, the soft film 200 covering the bare cell 100 can achieve high sealing performance, stability, and safety.

[0092] Based on the same inventive concept and in conjunction with the description of the pouch cells in the above embodiments, this embodiment provides a battery module that has the corresponding technical effects of the pouch cells in the above embodiments, which will not be repeated here.

[0093] A battery module includes pouch cells as described in the above embodiments.

[0094] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0095] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0096] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0097] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0098] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0099] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A pouch cell, characterized in that, include: A bare battery cell, the bare battery cell comprising a cell body, wherein at least one end of the cell body along a first direction is formed with a tab; The soft-film includes two half-films respectively disposed on opposite sides of the bare battery cell, each half-film including a first film surface close to the bare battery cell; at least one half-film is provided with a pit, and the two half-films are thermally fused together so that the pit forms a receiving cavity for accommodating the bare battery cell; The recess includes two side surfaces arranged opposite each other along a second direction, and a bottom surface connected to both side surfaces; the first membrane surface includes an outer sub-surface surrounding the recess; the edge of the side surface near the outer sub-surface is aligned with the edge of the side surface near the bottom surface along a third direction; the first direction, the second direction, and the third direction are mutually perpendicular.

2. The soft-pack battery cell according to claim 1, characterized in that, A first bottom chamfer is provided between the bottom surface and the side surface; along the second direction, the battery cell body is located on the side closer to the bottom surface at the connection position between the first bottom chamfer and the bottom surface.

3. The soft-pack battery cell according to claim 2, characterized in that, The radius of the first bottom chamfer is R1, where 3mm ≤ R1 ≤ 4.5mm.

4. The soft-pack battery cell according to claim 1, characterized in that, A first top round chamfer is provided between the outer edge sub-face and the side surface, and the radius of the first top round chamfer is R2, 2mm≤R2≤3mm.

5. The soft-pack battery cell according to claim 2, characterized in that, The semi-film includes a heat-sealing layer, a metal layer, and a protective layer that are sequentially stacked along a direction away from the bare cell; A first top chamfer is provided between the outer sub-surface and the side surface. The thickness of the metal layer of the first bottom chamfer is H1, the thickness of the metal layer of the first top chamfer is H2, and the thickness of the metal layer of the outer sub-surface is H3.

6. The soft-pack battery cell according to claim 1, characterized in that, The recess includes two side end faces arranged opposite each other along a first direction, and a gas storage space for storing gas is formed between the side end faces and the main body of the battery cell. The edge of the side end face near the outer sub-face is aligned with the edge of the side end face near the bottom face along the third direction.

7. The soft-pack battery cell according to claim 6, characterized in that, A second bottom chamfer is provided between the side end face and the bottom surface. Along the first direction, the main body of the battery cell is located on the side closer to the bottom surface at the connection position between the second bottom chamfer and the bottom surface.

8. The soft-pack battery cell according to claim 6, characterized in that, A second top round chamfer is provided between the side end face and the outer edge sub-face, and part of the pole lug is bent along the second top round chamfer.

9. The soft-pack battery cell according to claim 1, characterized in that, The maximum dimension of the pouch cell along the third direction is H, where H ≥ 12 mm.

10. A battery module, characterized in that, Includes the pouch cell as described in any one of claims 1 to 9.

Images