Battery cell and battery

Abstract

The utility model discloses a battery cell and a battery. The battery cell comprises a main body, the main body has a set thickness direction, at least one side of the main body in the thickness direction is provided with an accommodating groove, the accommodating groove is recessed in the outer surface of the main body in the thickness direction along the thickness direction, the accommodating groove is located at the outer edge of the main body in the first direction, the accommodating groove is used for accommodating the folded edge of the outer coating film, and the first direction is perpendicular to the thickness direction. After the main body is subjected to wrapping edge sealing and edge folding operation by the outer wrapping film, the folded edge of the outer wrapping film can be accommodated in the accommodating groove formed in the main body, so that the structure of the battery cell is more compact, the probability that the folded edge protrudes out of the end surface of the main body in the thickness direction is reduced, the subsequent assembly of the battery cell is ensured, and the energy density of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of secondary batteries, in particular to a battery core and a battery. Background Art

[0002] In the related art, after the cathode and anode sheets are assembled to form the main body, they need to be packaged to improve the safety of the battery cell. In the case of using an outer film for packaging, after the outer film is wrapped around the main body and sealed, the outer film needs to be folded to make the structure of the battery cell compact. However, in the folding method of the related art, after the folding operation is completed, there is still a high probability that the folded edge of the outer film will protrude from the end face in the thickness direction of the main body, which increases the size of the battery cell, affects the compactness of the battery cell and affects subsequent assembly, and reduces the energy density of the battery. Therefore, it is necessary to conduct research and improvement on the above-mentioned problems. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery core that can make the battery core structure more compact.

[0004] The utility model also provides a battery having the battery core.

[0005] According to the battery cell of the embodiment of the utility model, the main body includes a set thickness direction, and a receiving groove is provided on at least one side of the thickness direction of the main body. The receiving groove is recessed along the thickness direction in the outer surface of the main body in the thickness direction, and the receiving groove is located at the outer edge of the first direction of the main body. The receiving groove is used to receive the folded edge of the outer packaging film, and the first direction is perpendicular to the thickness direction.

[0006] The battery cell according to the embodiment of the utility model has at least the following beneficial effects: after the outer film is wrapped around the main body and the edge is sealed and folded, the receiving groove provided on the main body allows the folded edge of the outer film to be accommodated in the receiving groove, the structure of the battery cell is more compact, and the probability of the folded edge protruding from the end face of the main body in the thickness direction is reduced, thereby ensuring the subsequent assembly of the battery cell.

[0007] According to some embodiments of the present invention, the main body has a first side and a second side opposite to each other in the first direction, and the outer edge of the first side of the main body and the outer edge of the second side of the main body are respectively provided with the accommodating groove.

[0008] According to some embodiments of the present invention, the accommodating groove located on the first side and the accommodating groove located on the second side are both located on the same side of the main body in the thickness direction.

[0009] According to some embodiments of the present utility model, the main body includes a first pole segment group and a second pole segment group, the first pole segment group and the second pole segment group are stacked along a second direction, the first pole segment group and the second pole segment group each include at least one pole segment, the size of the pole segment of the first pole segment group in the first direction is smaller than the size of the pole segment of the second pole segment group in the first direction, and the accommodating groove is defined between the pole segment of the first pole segment group and the pole segment of the second pole segment group.

[0010] According to some embodiments of the utility model, the main body includes a first sub-cell and a second sub-cell, the first sub-cell and the second sub-cell are alternately stacked along the thickness direction, the size of the first sub-cell in the first direction is smaller than the size of the second sub-cell in the first direction, and the outer surface of the first sub-cell and the outer surface of the second sub-cell define the accommodating groove.

[0011] According to some embodiments of the present invention, the first sub-battery cell is centered with respect to the second sub-battery cell in the first direction, and both sides of the first sub-battery cell in the first direction define the accommodation groove with the second sub-battery cell.

[0012] According to some embodiments of the present invention, the first sub-cell includes a first anode sheet and a first cathode sheet, and the first anode sheet and the first cathode sheet are stacked alternately to form the first sub-cell; the second sub-cell includes a second anode sheet and a second cathode sheet, and the second anode sheet and the second cathode sheet are stacked alternately to form the second sub-cell; or, the first sub-cell includes a first anode sheet and a first cathode sheet, and the first anode sheet and the first cathode sheet are wound to form the first sub-cell; the second sub-cell includes a second anode sheet and a second cathode sheet, and the second anode sheet and the second cathode sheet are wound to form the second sub-cell.

[0013] According to some embodiments of the utility model, the battery cell also includes an outer packaging film, which includes a covering portion and a folded edge portion connected to each other, the covering portion covers the main body, the folded edge portion is located at the outer edge of the covering portion in the first direction, the folded edge portion is bent along a direction toward the accommodating groove, and at least a portion of the folded edge portion is located in the accommodating groove.

[0014] According to some embodiments of the utility model, the folded edge portion includes a first bending section and a second bending section, the first bending section is connected to the covering portion, the first bending section is bent toward the accommodating groove, at least a portion of the first bending section is located in the accommodating groove, the second bending section is connected to the first bending section, the second bending section is bent toward the first bending section toward one side of the main body, and the second bending section is located in the accommodating groove.

[0015] According to some embodiments of the utility model, the main body has a third side and a fourth side in the thickness direction, the main body has a groove wall in the first direction, the main body has a groove bottom on the third side, the groove wall and the groove bottom are connected to each other and jointly define the accommodating groove, the size of the groove bottom in the first direction is L1, and the distance between the groove bottom and the end face of the main body on the fourth side is L2; ​​the folded edge portion has a set extension dimension D on the plane formed by the first direction and the thickness direction, satisfying: D≤L1+L2.

[0016] According to some embodiments of the utility model, the main body includes a first sub-cell and a second sub-cell, and the first sub-cell and the second sub-cell are alternately stacked along the thickness direction, the size of the first sub-cell in the first direction is smaller than the size of the second sub-cell in the first direction, and the outer surface of the first sub-cell in the first direction and the outer surface of the second sub-cell in the thickness direction define the accommodating groove; the covering portion is provided with a groove, and the groove includes a first groove section and a second groove section that are interconnected, the size of the first groove section in the first direction is smaller than the size of the second groove section in the first direction, the first groove section is used to accommodate the first sub-cell, and the second groove section is used to accommodate at least a part of the second sub-cell.

[0017] A battery according to an embodiment of the utility model includes a battery cell in any of the above embodiments.

[0018] The battery according to the embodiment of the utility model has at least the following beneficial effects: the battery cell structure of the embodiment of the present application is compact, and the battery composed of the battery cells of the embodiment of the present application can ensure the assembly yield and improve the energy density of the battery.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0021] Figure 1 It is a schematic diagram of a battery cell in an uncoated state according to an embodiment of the utility model;

[0022] Figure 2 Schematic diagram of battery cells of some embodiments of the utility model;

[0023] Figure 3 This is a schematic diagram of a battery cell in some embodiments of the utility model in a completed coating state;

[0024] Figure 4 This is a schematic diagram of a state where a battery cell of some embodiments of the utility model is in a film package;

[0025] Figure 5 for Figure 3 A partial schematic diagram of the outer envelope in FIG.

[0026] Figure 6 Schematic diagrams of battery cells in other embodiments of the present utility model in an uncoated state;

[0027] Figure 7 Schematic diagrams of battery cells in other embodiments of the present utility model in an uncoated state;

[0028] Reference numerals:

[0029] Main body 100, first sub-cell 110, first anode sheet 111, first cathode sheet 112, second sub-cell 120, second anode sheet 121, second cathode sheet 122, accommodating groove 130, groove wall 131, groove bottom 132, first pole piece 140, first sub-pole piece 141, second sub-pole piece 142, second pole piece 150, third sub-pole piece 151, fourth sub-pole piece 152, first pole segment group 160, second pole segment group 170, pole segment 180;

[0030] The outer film 200 , the covering portion 210 , the folded edge portion 220 , the first bending section 221 , the second bending section 222 , the groove 230 , the first groove section 231 , and the second groove section 232 . DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0035] In the description of the utility model, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0036] In view of the problem in the related art that there is still a high probability that the folded edge of the outer film will protrude from the end face in the thickness direction of the main body, the present application provides a receiving groove on the main body to accommodate the folded edge of the outer film, so as to reduce the probability of the folded edge of the outer film protruding from the end face in the thickness direction of the main body, thereby making the structure of the battery cell more compact.

[0037] The following describes the cell and battery of the embodiment of the present application with reference to the drawings of the specification. It should be noted that the thickness direction is shown in the up-down direction in the drawings, and the first direction is shown in the left-right direction, wherein the left side is the first side and the right side is the second groove.

[0038] Reference Figure 1 and Figure 3According to the battery cell of the embodiment of the utility model, the battery cell includes a main body 100, the main body 100 has a set thickness direction, and a receiving groove 130 is provided on at least one side of the thickness direction of the main body 100. The receiving groove 130 is recessed in the outer surface of the main body 100 in the thickness direction along the thickness direction. The receiving groove 130 is located at the outer edge of the first direction of the main body 100. The receiving groove 130 is used to accommodate the folded edge of the outer film 200, and the first direction is perpendicular to the thickness direction. After the outer film 200 covers and seals the main body 100 and performs the folding operation, the receiving groove 130 provided on the main body 100 allows the folded edge of the outer film 200 to be accommodated in the receiving groove 130, the structure of the battery cell is more compact, and the probability of the folded edge protruding from the end face of the main body 100 in the thickness direction is reduced, ensuring the subsequent assembly of the battery cell.

[0039] It is understandable that the first direction may be selected as the length direction of the main body 100 or the width direction, and may be adaptively changed according to the requirements of the encapsulation operation.

[0040] In some embodiments, the main body 100 is provided with a single receiving groove 130, which is located in the thickness direction of the main body 100 and at the outer edge of one side of the first direction of the main body 100. After the outer film 200 covers and seals the main body 100, the area that needs to be folded can be mainly reserved on the side of the main body 100 where the receiving groove 130 is provided, so that the folded edge of the outer film 200 can be accommodated by the receiving groove 130, so as to reduce the probability of the folded edge protruding from the end surface of the main body 100 in the thickness direction.

[0041] In some embodiments, the main body 100 is provided with a plurality of accommodating grooves 130, and the main body 100 has a first side and a second side relative to each other in a first direction, and the outer edge of the first side of the main body 100 and the outer edge of the second side of the main body are respectively provided with accommodating grooves 130, so that after the outer film 200 covers and seals the main body 100, both sides of the main body 100 in the first direction have accommodating grooves 130 to accommodate the folded edges, so as to further reduce the probability of the folded edges protruding from the end face in the thickness direction of the main body 100.

[0042] Furthermore, the accommodating groove 130 located on the first side and the accommodating groove 130 located on the second side are both located on the same side of the thickness direction of the main body 100, so that the space on the same side of the thickness direction of the main body 100 can be utilized to set the accommodating groove 130, thereby improving space utilization and facilitating the processing of the main body 100 and the subsequent folding operation of the outer packaging film 200.

[0043] Reference Figure 6 and Figure 7In some embodiments, the main body 100 includes a first pole segment group 160 and a second pole segment group 170, the first pole segment group 160 and the second pole segment group 170 are stacked along the second direction, the first pole segment group 160 and the second pole segment group 170 each include at least one pole segment 180, the size of the pole segment 180 of the first pole segment group 160 in the first direction is smaller than the size of the pole segment 180 of the second pole segment group 170 in the first direction, and an accommodating groove 130 is defined between the pole segment 180 of the first pole segment group 160 and the pole segment 180 of the second pole segment group 170. The accommodating groove 130 can be defined by the size difference between the pole segments 180 of the first pole segment group 160 and the second pole segment group 170.

[0044] For example, refer to Figure 6 In some embodiments, the size of the first pole piece 140 at the upper end portion in the first direction is smaller than the size of the adjacent second pole piece 150 in the first direction. The first pole piece 140 at the upper end portion is the first pole piece group 160, and the other first pole pieces 140 and second pole pieces 150 are the second pole piece group 170. The first pole piece 140 at the upper end portion and the adjacent second pole piece 150 define a receiving groove 130, and the receiving groove 130 is defined by the size difference between the adjacent first pole piece 140 and the second pole piece 150.

[0045] For example, refer to Figure 7 In other embodiments, the first pole piece 140 includes a first sub-pole piece 141 and a second sub-pole piece 142, the first sub-pole piece 141 is located on the upper side of the second sub-pole piece 142, and the size of the first sub-pole piece 141 in the first direction is smaller than the size of the second sub-pole piece 142 in the first direction. The second pole piece 150 includes a third sub-pole piece 151 and a fourth sub-pole piece 152, the third sub-pole piece 151 is located on the upper side of the fourth sub-pole piece 152, and the size of the third sub-pole piece 151 in the first direction is smaller than the size of the fourth sub-pole piece 152 in the first direction, the first sub-pole piece 141 and the third sub-pole piece 151 are alternately arranged, and the third sub-pole piece 151 and the fourth sub-pole piece 152 are alternately arranged, and the first sub-pole piece 141, the third sub-pole piece 151 and the second sub-pole piece 142, the fourth sub-pole piece 152 define a receiving groove 130 between them. The first sub-pole piece 141 and the second sub-pole piece 142 have a size difference, and the third sub-pole piece 151 and the fourth sub-pole piece 152 have a size difference, so that the first sub-pole piece 141, the third sub-pole piece 151, the second sub-pole piece 142 and the fourth sub-pole piece 152 define a receiving groove 130, and the depth of the receiving groove 130 in the second direction can be further controlled. Among them, the first sub-pole piece 141 and the third sub-pole piece 151 form a first pole piece group 160, and the second sub-pole piece 142 and the fourth sub-pole piece 152 form a second pole piece group 170.

[0046] Reference Figure 1 In some embodiments, the main body 100 includes a first sub-cell 110 and a second sub-cell 120, the first sub-cell 110 and the second sub-cell 120 are alternately stacked in the thickness direction, the size of the first sub-cell 110 in the first direction is smaller than the size of the second sub-cell 120 in the first direction, and the outer surface of the first sub-cell 110 in the first direction and the outer surface of the second sub-cell 120 in the thickness direction define a receiving groove 130. The receiving groove 130 can be conveniently defined by the size difference between the first sub-cell 110 and the second sub-cell 120 in the first direction.

[0047] By adjusting the positions of the first sub-cell 110 and the second sub-cell 120 in the first direction, the number of the receiving grooves 130 defined by the first sub-cell 110 and the second sub-cell 120 and the size of the receiving grooves 130 can be adjusted. For example, in some embodiments, the first sub-cell 110 and the second sub-cell 120 are aligned on the first side in the first direction to form a larger receiving groove 130 on the second side. Alternatively, in other embodiments, in the first direction, the two sides of the first sub-cell 110 in the first direction are located between the two sides of the second sub-cell 120 in the first direction to define the receiving grooves 130 on both sides of the main body 100 in the first direction. In a further embodiment, the first sub-cell 110 is centered on the second sub-cell 120 in the first direction to define the receiving grooves 130 of uniform size with the second sub-cell 120 on both sides of the first sub-cell 110 in the first direction, which is conducive to the standardization of the battery cells.

[0048] Reference Figure 2 In the embodiment where the main body 100 includes a first sub-cell 110 and a second sub-cell 120, the first sub-cell 110 includes a first anode sheet 111 and a first cathode sheet 112, and the first anode sheet 111 and the first cathode sheet 112 are stacked alternately to form the first sub-cell 110, so that the first sub-cell 110 is composed of a laminated cell. The second sub-cell 120 includes a second anode sheet 121 and a second cathode sheet 122, and the second anode sheet 121 and the second cathode sheet 122 are stacked alternately to form the second sub-cell 120, so that the second sub-cell 120 is composed of a laminated cell.

[0049] Reference Figure 2In some other embodiments where the main body 100 includes a first sub-cell 110 and a second sub-cell 120, the first anode sheet 111 and the first cathode sheet 112 are wound to form the first sub-cell 110, so that the first sub-cell 110 is composed of a wound cell. The second sub-cell 120 includes a second anode sheet 121 and a second cathode sheet 122, and the second anode sheet 121 and the second cathode sheet 122 are wound to form the second sub-cell 120, so that the second sub-cell 120 is composed of a wound cell. The winding process and winding structure of the first anode sheet 111 and the first cathode sheet 112, the second anode sheet 121 and the second cathode sheet 122 can be specifically referred to the wound cell in the relevant technology, and this application will not be described and displayed in detail.

[0050] In some embodiments, reference Figure 1 and Figure 3 The outer film 200 wrapped around the outside of the main body 100 includes a wrapping portion 210 and a folding portion 220 connected to each other. The wrapping portion 210 wraps the main body 100. The folding portion 220 is located at the outer edge of the wrapping portion 210 in the first direction. The folding portion 220 is bent in the direction toward the receiving groove 130, and at least a part of the folding portion 220 is located in the receiving groove 130. The wrapping portion 210 realizes the wrapping of the main body 100. The folding portion 220 enables the redundant part of the outer film 200 to be bent and fit the main body 100 as much as possible, so as to make the battery cell structure compact. The end of the folding portion 220 is located in the receiving groove 130, so as to accommodate the folding portion 220 through the receiving groove 130, and reduce the probability of the folding portion 220 protruding from the end face of the main body 100 in the thickness direction.

[0051] Reference Figure 3 and Figure 4 In a further embodiment, the hem portion 220 includes a first bending section 221 and a second bending section 222, the first bending section 221 is connected to the covering portion 210, the first bending section 221 is bent toward the receiving groove 130, at least a portion of the first bending section 220 is located in the receiving groove 130, the second bending section 222 is connected to the first bending section 221, the second bending section 222 is bent toward the first bending section 221 toward the side of the main body 100, and the second bending section 222 is located in the receiving groove 130. Through the first bending of the first bending section 221, the hem portion 220 can be close to the main body 100, and through the second bending of the second bending section 222, the ends of the hem portion 220 can be overlapped, so as to control the overall length of the hem portion 220 and reduce the probability that the hem portion 220 passes over the receiving groove 130 and protrudes from the end surface of the main body 100 in the first direction. The second bending section 222 and the outer surface of the bearing portion can be bonded together by hot melt adhesive or other colloids to increase the bonding strength and ensure the stability of the coating of the outer film 200 .

[0052] Further, the main body 100 has a third side and a fourth side in the thickness direction, the main body 100 has a groove wall 131 in the first direction, the main body 100 has a groove bottom 132 on the third side, the groove wall 131 and the groove bottom 132 are connected to each other and jointly define the accommodating groove 130, the size of the groove bottom 132 in the first direction is L1, and the distance between the groove bottom 132 and the end surface of the main body 100 on the fourth side is L2. The folding portion 220 has a set extension dimension D on the plane formed by the first direction and the thickness direction. Satisfies: D≤L1+L2. By controlling D≤L1+L2, it can be ensured that after the folding portion 220 is bent, the second bending section 222 can be completely accommodated in the receiving groove 130, and a part of the first bending section 221 is located in the receiving groove 130, reducing the problem of the end surface protruding from the thickness direction of the main body 100 due to the excessive extension length of the folding portion 220, and can control the thickness formed after the first bending section 221 is folded on the first bending section 221, so as to ensure the compact structure of the battery cell. It should be noted that the extension direction of the folding portion 220 refers to the extension length of the folding portion 220 relative to the covering portion 210 after the outer film 200 completes the coating of the battery cell to form the covering portion 210 and the folding portion 220, that is, the extension distance of the folding portion 220 from the connection with the covering portion 210 to the end of the folding portion 220 away from the covering portion 210. The measurement of the extension distance can be carried out when the folding portion 220 is in the unfolded state.

[0053] As another improvement of the above scheme, in an embodiment where the main body 100 includes a first sub-cell 110 and a second sub-cell 120, the covering portion 210 is provided with a groove 230, and the groove 230 includes a first groove section 231 and a second groove section 232 that are interconnected, and the size of the first groove section 231 in the first direction is smaller than the size of the second groove section 232 in the first direction, and the first groove section 231 is used to accommodate the first sub-cell 110, and the second groove section 232 is used to accommodate at least a portion of the second sub-cell 120. By providing the groove 230 in advance on the covering portion 210, the positioning difficulty of the covering portion 210 when covering the main body 100 can be reduced, and the covering of the covering portion 210 to the main body 100 can be made more closely, thereby improving the covering effect. Among them, the groove 230 can be formed by one-time stamping of a mold having a shape that is adapted to the first groove section 231 and the second groove section 232, or can be formed by multiple stamping of two molds of different sizes.

[0054] Reference Figure 1 and Figure 3 The battery according to the embodiment of the utility model comprises the battery cell of any of the above embodiments. The battery cell structure of the embodiment of the present application is compact. By applying the battery cell of the embodiment of the present application, the assembly yield can be ensured and the energy density of the battery can be improved.

[0055] The embodiments of the utility model are described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the utility model. In addition, the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery cell, characterized in that: include: A main body has a set thickness direction, and a receiving groove is provided on at least one side of the thickness direction of the main body. The receiving groove is recessed along the thickness direction in the outer surface of the main body in the thickness direction. The receiving groove is located at the outer edge of the first direction of the main body. The receiving groove is used to accommodate the folded edge of the outer membrane, and the first direction is perpendicular to the thickness direction.

2. The battery cell according to claim 1, characterized in that: The main body has a first side and a second side opposite to each other in the first direction, and the outer edge of the first side of the main body and the outer edge of the second side of the main body are respectively provided with the accommodating grooves.

3. The battery cell according to claim 2, characterized in that: The receiving groove located at the first side and the receiving groove located at the second side are both located at the same side of the body in the thickness direction.

4. The battery cell according to claim 1, characterized in that: The main body includes a first pole segment group and a second pole segment group, the first pole segment group and the second pole segment group are stacked along a second direction, the first pole segment group and the second pole segment group each include at least one pole segment, the size of the pole segment of the first pole segment group in the first direction is smaller than the size of the pole segment of the second pole segment group in the first direction, and the accommodating groove is defined between the pole segment of the first pole segment group and the pole segment of the second pole segment group.

5. The battery cell according to claim 1, characterized in that: The main body includes a first sub-cell and a second sub-cell, the first sub-cell and the second sub-cell are alternately stacked along the thickness direction, the size of the first sub-cell in the first direction is smaller than the size of the second sub-cell in the first direction, and the outer surface of the first sub-cell and the outer surface of the second sub-cell define the receiving groove.

6. The battery cell according to claim 5, characterized in that: The first sub-cell is centered with respect to the second sub-cell in the first direction, and both sides of the first sub-cell in the first direction define the accommodation groove with the second sub-cell.

7. The battery cell according to claim 5, characterized in that: The first sub-cell comprises a first anode sheet and a first cathode sheet, and the first anode sheet and the first cathode sheet are alternately stacked to form the first sub-cell; the second sub-cell comprises a second anode sheet and a second cathode sheet, and the second anode sheet and the second cathode sheet are alternately stacked to form the second sub-cell; Alternatively, the first sub-cell includes a first anode sheet and a first cathode sheet, and the first anode sheet and the first cathode sheet are wound to form the first sub-cell; the second sub-cell includes a second anode sheet and a second cathode sheet, and the second anode sheet and the second cathode sheet are wound to form the second sub-cell.

8. The battery cell according to any one of claims 1 to 7, characterized in that: It also includes an outer membrane, which includes a covering portion and a folded edge portion that are connected to each other, the covering portion covers the main body, the folded edge portion is located at the outer edge of the covering portion in the first direction, the folded edge portion is bent along a direction toward the accommodating groove, and at least a portion of the folded edge portion is located in the accommodating groove.

9. The battery cell according to claim 8, characterized in that: The folded edge portion includes a first bending section and a second bending section, the first bending section is connected to the covering portion, the first bending section is bent toward the accommodating groove, at least a portion of the first bending section is located in the accommodating groove, the second bending section is connected to the first bending section, the second bending section is bent toward the first bending section toward one side of the main body, and the second bending section is located in the accommodating groove.

10. The battery cell according to claim 8, characterized in that: The main body has a third side and a fourth side in the thickness direction, the main body has a groove wall in the first direction, the main body has a groove bottom on the third side, the groove wall and the groove bottom are connected to each other and jointly define the accommodating groove, the size of the groove bottom in the first direction is L1, and the distance between the groove bottom and the end face of the main body on the fourth side is L2; ​​the folded edge portion has a set extension dimension D on the plane formed by the first direction and the thickness direction, satisfying: D≤L1+L2.

11. The battery cell according to claim 8, characterized in that: The main body includes a first sub-cell and a second sub-cell, the first sub-cell and the second sub-cell are alternately stacked along the thickness direction, the size of the first sub-cell in the first direction is smaller than the size of the second sub-cell in the first direction, the outer surface of the first sub-cell in the first direction and the outer surface of the second sub-cell in the thickness direction define the accommodating groove; the covering portion is provided with a groove, the groove includes a first groove section and a second groove section which are interconnected, the size of the first groove section in the first direction is smaller than the size of the second groove section in the first direction, the first groove section is used to accommodate the first sub-cell, and the second groove section is used to accommodate at least a part of the second sub-cell.

12. A battery, characterized in that A battery cell comprising the battery cell according to any one of claims 1 to 11.

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