Battery cell, battery and electric device

Abstract

The present application relates to the technical field of batteries. Provided are a battery cell, a battery and an electric device. The battery cell comprises a casing, binding portions and at least one electrode assembly, wherein the casing is provided with first wall portions; the electrode assembly is accommodated in the casing, and comprises electrode sheets stacked in a first direction, the electrode sheets and the first wall portions being stacked in the first direction; the electrode assembly comprises a body portion and tabs, the tabs being provided on at least one section of the body portion in a second direction, and the first direction intersecting with the second direction; the binding portions are disposed in the casing; and in the first direction, the tabs of the electrode assembly that is closest to the first wall portions are first tabs, the binding portions are connected to an insulating body, and at least parts of the binding portions extend to positions between the first tabs and the first wall portions and abut against the surfaces of the first tabs facing the first wall portions. The improvement of the cycle performance of the battery cell is facilitated.

Description

Battery cells, batteries and electrical equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese patent application No. 202420290165.6, filed on February 8, 2024, entitled “Battery Cell, Battery and Electrical Equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0003] Batteries are widely used in new energy vehicles, electronic devices and other fields. As the demand for batteries increases, higher requirements are placed on the battery's cycle performance. As the scope of battery applications becomes wider, higher requirements are placed on the battery's cycle performance. Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device to improve the cycle performance of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, a restraining portion and at least one electrode assembly; the shell has a first wall portion; the electrode assembly is accommodated in the shell, the electrode assembly comprises pole pieces stacked along a first direction, the pole pieces and the first wall portion are stacked along the first direction, the electrode assembly comprises a main body portion and a pole ear, the main body portion is provided with the pole ear in at least one section along a second direction, and the first direction and the second direction intersect; the restraining portion is arranged in the shell; wherein, along the first direction, the pole ear of the electrode assembly closest to the first wall portion is the first pole ear, and the restraining portion is at least partially located between the first pole ear and the first wall portion, and abuts against the surface of the first pole ear facing the first wall portion.

[0006] In the above technical solution, the outer shell of the battery cell has a first wall portion arranged along the first direction with the pole piece, and the binding portion abuts against the side of the first pole ear of the electrode assembly closest to the first wall portion facing the first wall portion, providing a binding force for the first pole ear, reducing the gap between the layers of the first pole ear, thereby reducing the gap between the pole piece main body areas connected to the first pole ear, so that the gap between the pole pieces on the side close to the first wall portion of the electrode assembly closest to the first wall portion is smaller, which is beneficial to improving the cycle performance of the battery cell.

[0007] In some embodiments of the first aspect of the present application, the electrode assembly closest to the first wall portion along the first direction has a center plane, the center plane is perpendicular to the first direction, and the first electrode tab is at least partially arranged on a side of the center plane close to the first wall portion.

[0008] In the above technical solution, the first pole ear is at least partially arranged on the side of the center surface of the electrode assembly closest to the first wall portion, so that the binding portion and the first pole ear are more easily abutted, and the binding portion provides binding force for the first pole ear, which is beneficial to reducing the gap between the layers of the first pole ear, thereby reducing the gap between the main areas of the pole pieces connected to the first pole ear, so that the gap between the pole pieces on the side of the electrode assembly closest to the first wall portion close to the first wall portion is smaller, which is beneficial to improving the cycle performance of the battery cell.

[0009] In some embodiments of the first aspect of the present application, along the first direction, there is a distance between the first wall portion and the main body portion of the electrode assembly closest to the first wall portion.

[0010] In the above technical solution, along the first direction, there is a distance between the first wall portion and the main body portion of the electrode assembly closest to the first wall portion, which provides expansion space for the electrode assembly, reduces the risk of explosion, fire and other problems in the battery cell, and improves the reliability of the battery cell.

[0011] In some embodiments of the first aspect of the present application, the first pole tab includes a plurality of pole tab sheets stacked along the first direction, and the connection position between the main body and the pole tab sheet closest to the first wall portion among the plurality of pole tab sheets of the first pole tab is the first position; the restraining portion has a resting end resting against the first pole tab, and along the first direction, the distance between the end of the resting end away from the first wall portion and the surface resting against the first pole tab and the first wall portion is greater than the distance between the first position and the first wall portion.

[0012] In the above technical solution, along the first direction, the distance between the end of the restraining portion away from the first wall portion and the surface against which the first pole ear abuts and the first wall portion is greater than the distance between the first position and the first wall portion, so that the restraining portion can squeeze the first pole ear in the first direction away from the first wall portion, thereby reducing the gap between the layers of the first pole ear, thereby reducing the gap between the pole piece main body areas connected to the first pole ear, so that the gap between the pole pieces on the side of the electrode assembly closest to the first wall portion close to the first wall portion is smaller, which is beneficial to improving the cycle performance of the battery cell.

[0013] In some embodiments of the first aspect of the present application, the surface of the abutting end abutting against the first electrode tab is a curved surface.

[0014] In the above technical solution, the surface of the abutting end that abuts against the first electrode tab is a curved surface, which can reduce the risk of damaging the first electrode tab when the abutting end abuts against the first electrode tab.

[0015] In some embodiments of the first aspect of the present application, the shell has a second wall portion, the second wall portion and the pole lug are arranged along the second direction, the battery cell includes an electrode terminal, and the electrode terminal is arranged on the second wall portion; the first pole lug includes a first pole lug root portion, a first bending portion and a first connecting portion, the first pole lug root portion is connected to the main body portion, the first bending portion connects the first pole lug root portion and the first connecting portion, and the first connecting portion is electrically connected to the electrode terminal; the binding portion abuts against the surface of the first pole lug root portion facing the first wall portion.

[0016] In the above technical solution, the binding portion abuts against the surface of the root of the first pole ear facing the first wall portion, so that the abutment position of the binding portion against the first pole ear is closer to the pole piece main body area connected to the first pole ear, thereby better restraining the pole piece main body area, which is more conducive to reducing the gap between the pole pieces on the side of the electrode assembly closest to the first wall portion close to the first wall portion, and is conducive to improving the cycle performance of the battery cell.

[0017] In some embodiments of the first aspect of the present application, the battery cell further includes an insulating layer, and the insulating layer is at least partially disposed on a surface of the first electrode tab root.

[0018] In the above technical solution, the battery cell further includes an insulating layer at least partially disposed on the surface of the root of the first pole tab, which is beneficial to improving the strength of the first pole tab and reducing the risk of the first pole tab being torn.

[0019] In some embodiments of the first aspect of the present application, the restraining portion includes a resting section and an extension section, the extension section is at least partially located between the first pole ear and the first wall portion, and along the direction of the pole ear pointing to the main body portion, the resting section protrudes from one end of the extension section, and the resting section rests against the root of the first pole ear.

[0020] In the above technical solution, the binding portion includes a resting section and an extension section. The extension section is at least partially located between the first pole ear and the first wall portion. Along the direction of the pole ear pointing to the main body portion, the resting section protrudes from one end of the extension section. The resting section rests against the root of the first pole ear, which can reduce the space occupied by the binding portion, facilitate the rest against the first pole ear, and reduce the risk of interference between the first pole ear and the binding portion.

[0021] In some embodiments of the first aspect of the present application, the abutting section protrudes from the extending section in the first direction away from the first wall portion.

[0022] In the above technical solution, the abutting section protrudes from the extending section in the first direction away from the first wall portion, so that the abutting section is closer to the first electrode tab in the first direction, making it easier for the abutting section to abut against the first electrode tab.

[0023] In some embodiments of the first aspect of the present application, the electrode assembly closest to the first wall portion along the first direction has a center plane, the center plane is perpendicular to the first direction, and the first bending portion is located on the side of the center plane facing the first wall portion.

[0024] In the above technical solution, the first bent portion of the first pole ear is located on the side of the electrode assembly closest to the first wall portion, and the center surface faces the first wall portion. It can be understood that the multiple pole ear sheets of the first pole ear gather in the direction close to the first wall portion, reducing the distance between the surface of the first pole ear facing the first wall portion and the first wall portion, thereby facilitating the abutment between the binding portion and the first pole ear.

[0025] In some embodiments of the first aspect of the present application, the restraining portion includes an extending section and a supporting section, and the supporting section is bent from the extending section toward the first tab.

[0026] In the above technical solution, the abutment section bends toward the first tab, facilitating abutment between the abutment section and the first tab. The abutment section bends toward the first tab, allowing the end of the abutment section away from the extension section to abut against the base of the first tab. This not only provides better binding force for the first tab, but also reduces the risk of excessive contact area between the first tab and the abutment section, which could interfere with the connection between the first tab and other structures.

[0027] In some embodiments of the first aspect of the present application, the abutting section forms an abutting end at one end away from the extension section, and the abutting end abuts against the first pole ear. The abutting section has a first surface facing the first pole ear, and the first surface extends to the abutting end, and the first surface is an arc surface.

[0028] In the above technical solution, the end of the abutting section away from the extension section forms an abutting end that abuts the first tab. That is, the end of the abutting section away from the extension section can abut the first tab, which not only provides better binding force to the first tab, but also reduces the risk of excessive contact area between the first tab and the abutting section, thereby interfering with the connection between the first tab and other structures. The first surface is a curved surface, which facilitates the formation of a structure in which the abutting section bends toward the first tab, facilitating the manufacturing and forming of the abutting section and facilitating the abutment of the abutting section against the first tab.

[0029] In some embodiments of the first aspect of the present application, the extension section has a second surface facing the first pole ear, the first surface and the second surface are connected, and the distance between the second surface and the first wall portion in the first direction gradually increases along the direction of the pole ear pointing to the main body.

[0030] In the above technical solution, the extension section has a second surface facing the first pole ear. Along the direction of the pole ear toward the main body, the distance between the second surface and the first wall in the first direction gradually increases, thereby reducing the risk of the extension section over-extruding the first pole ear and causing the first pole ear to crack.

[0031] In some embodiments of the first aspect of the present application, the electrode assembly closest to the first wall portion includes a plurality of first pole ears, and the plurality of first pole ears are arranged along the third direction; the extension section is provided with a plurality of abutment sections, and the plurality of abutment sections are arranged at intervals along the third direction, one first pole ear corresponds to at least one abutment section, and the first direction, the second direction and the third direction are not coplanar and intersect with each other.

[0032] In the above technical solution, the electrode assembly closest to the first wall portion includes multiple first pole tabs, and the extension section is provided with multiple abutment sections, each abutment section abuts against a first pole tab, which can provide better binding force for each first pole tab.

[0033] In some embodiments of the first aspect of the present application, the shell has a second wall portion, the second wall portion and the first wall portion are adjacently arranged and connected, and the second wall portion and the pole lug are arranged along the second direction; the battery cell also includes an insulating body, the insulating body is arranged on the side of the pole lug facing the second wall portion to insulate and isolate the second wall portion and the pole lug, and the binding portion is connected to the insulating body.

[0034] In the above technical solution, the battery cell further includes an insulating body, which is arranged between the second wall and the side of the tab facing the second wall to reduce the risk of internal short circuit in the battery cell and improve the reliability of the battery cell.

[0035] In some embodiments of the first aspect of the present application, the restraining portion includes an extension section and a resting section, the extension section is at least partially located between the first pole ear and the first wall portion, the resting section protrudes from one end of the extension section, and the resting section rests against the first pole ear; the battery cell also includes a second bending portion, which connects the insulating body and the extension section.

[0036] In the above technical solution, the insulating body and the extension section are connected by the second bending portion, so that the insulating body and the restraining portion can be integrated, which can improve the stability of the insulating body and the restraining portion inside the battery cell, thereby improving the reliability of the insulating body and the restraining portion.

[0037] In some embodiments of the first aspect of the present application, the thickness of the insulating body and the thickness of the extension section are both greater than the thickness of the second bent portion.

[0038] In the above technical solution, the thickness of the insulating body and the thickness of the extension section are both greater than the thickness of the second bending portion, so that the strength of the insulating body and the strength of the extension section are both greater than the strength of the second bending portion, which facilitates the extension section to be bent and formed relative to the insulating body at the second bending portion, thereby facilitating the insulating body and the binding portion to form an integral structure and be manufactured.

[0039] In some embodiments of the first aspect of the present application, the second bending portion is provided with a through hole, and the through hole passes through both sides of the second bending portion in the thickness direction; and / or the second bending portion is provided with a groove on at least one surface along the thickness direction of the second bending portion.

[0040] In the above technical solution, the second bend is provided with a through hole. The through hole is simple and convenient to form, thereby simplifying and conveniently reducing the strength of the second bend, making it easier to bend the second bend, thereby forming the insulating body, the restraining portion, and the second bend. The provision of the through hole also helps reduce the weight of the battery cell. The second bend is provided with a groove on at least one surface along the thickness direction of the second bend, thus simplifying and conveniently reducing the strength of the second bend.

[0041] In some embodiments of the first aspect of the present application, the battery cell includes a plurality of second bending portions, the plurality of second bending portions are arranged at intervals along a third direction, and the first direction, the second direction and the third direction are not coplanar and intersect with each other.

[0042] In the above technical solution, the battery cell includes a plurality of second bending portions spaced apart in the third direction, so that the connection stability between the insulating body and the extension section is better.

[0043] In some embodiments of the first aspect of the present application, the restraining portion is integrally formed with the insulating body.

[0044] In the above technical solution, the binding portion and the insulating body are integrally formed, which facilitates the binding portion and the insulating body to form an integrated structure, and is conducive to the overall structure formed by the binding portion and the insulating body having better strength.

[0045] In some embodiments of the first aspect of the present application, the battery includes a locking structure, which is used to lock the binding portion and the insulating body to limit the binding portion from flipping relative to the insulating body in a direction close to the first wall portion.

[0046] In the above technical solution, the binding portion and the insulating body are locked by a locking structure to limit the binding portion from flipping relative to the insulating body in the direction close to the first wall portion, so as to reduce the risk of the binding portion detaching from the first pole ear, so that the binding portion can stably bind the first pole ear, thereby reducing the gap between the pole pieces of the electrode assembly closer to the first wall portion, which is beneficial to improving the cycle performance of the battery cell.

[0047] In some embodiments of the first aspect of the present application, the locking structure includes a first locking portion and a second locking portion, and the first locking portion is configured to engage with the second locking portion to lock the insulating body and the restraining portion.

[0048] In the above technical solution, the first locking portion and the second locking portion are engaged with each other to facilitate locking of the insulating body and the restraining portion.

[0049] In some embodiments of the first aspect of the present application, the first locking portion is provided with a locking hole, and the second locking portion is engaged in the locking hole.

[0050] In the above technical solution, the first locking portion is provided with a locking hole, and the second locking portion is engaged in the locking hole, which not only facilitates the locking of the insulating body and the restraining portion, but also simplifies the structure of the locking structure.

[0051] In some embodiments of the first aspect of the present application, the second locking portion includes a first elastic portion and a second elastic portion arranged relatively spaced apart, and the second locking portion is configured to be able to be inserted into the locking hole when the first elastic portion and the second elastic portion are close to each other.

[0052] In the above technical solution, the second locking portion includes a first elastic portion and a second elastic portion that are arranged relatively spaced apart, so as to facilitate the engagement between the first locking portion and the second locking portion.

[0053] In some embodiments of the first aspect of the present application, the first locking portion is provided on the insulating body, and the second locking portion is provided on the restraining portion; or, the first locking portion is provided on the restraining portion, and the second locking portion is provided on the insulating body.

[0054] In the above technical solution, by arranging the first locking part on the insulating body and the second locking part on the binding part, or by arranging the first locking part on the binding part and the second locking part on the insulating body, that is, the first locking part and the second locking part are respectively arranged on the insulating body and the binding part, the arrangement of the first locking part and the second locking part and the snap-fitting of the first locking part and the second locking part are facilitated.

[0055] In some embodiments of the first aspect of the present application, the first locking portion is provided on the insulating body and protrudes from a surface of the insulating body facing the main body; the second locking portion is provided on the binding portion and protrudes from a surface of the binding portion facing the first tab.

[0056] In the above technical solution, the first locking portion is arranged on the insulating body and protrudes from the surface of the insulating body facing the main body; the second locking portion is arranged on the binding portion and protrudes from the surface of the binding portion facing the first pole ear, which facilitates the cooperation between the first locking portion and the second locking portion.

[0057] In some embodiments of the first aspect of the present application, the housing includes a shell and an end cover, the shell has an opening, the end cover covers the opening, and the second wall portion is the end cover.

[0058] In the above technical solution, the second wall portion is the end cover, and the first wall portion is the wall portion of the shell, which facilitates the arrangement of the electrode assembly and the first wall portion, thereby facilitating the assembly of the battery cell.

[0059] In some embodiments of the first aspect of the present application, a surface of the first electrode tab facing the first wall portion includes a concave surface, and the restraining portion abuts against the concave surface.

[0060] In the above technical solution, the surface of the first electrode tab facing the first wall portion includes a concave surface, and the binding portion abuts against the concave surface, so that the abutment between the binding portion and the first electrode tab is more stable.

[0061] In some embodiments of the first aspect of the present application, the shell includes two first wall portions arranged opposite to each other; the battery cell includes a plurality of the electrode assemblies, and the plurality of the electrode assemblies are arranged between the two first wall portions along the first direction, and the electrode tabs of the electrode assemblies at both ends along the first direction are both the first electrode tabs; the plurality of electrode assemblies are provided with the restraining portions on both sides along the first direction, and the restraining portions on both sides of the plurality of electrode assemblies respectively abut against the first electrode tabs of the electrode assemblies at both ends along the first direction.

[0062] In the above technical solution, multiple electrode assemblies are treated as a whole, and the whole is provided with a restraining portion on both sides along the first direction. The restraining portions on both sides of the multiple electrode assemblies respectively abut against the first pole ears of the electrode assemblies located at both ends along the first direction, and can restrain the first pole ears of the two electrode assemblies located at the endmost end, thereby reducing the gap between the layers of the first pole ears of the two electrode assemblies at the endmost end, thereby reducing the gap between the pole piece main body areas connected to the first pole ears, so that the gap between the pole pieces of the two electrode assemblies located at the endmost end on the side closest to the first wall portion is smaller, which is beneficial to improving the cycle performance of the battery cell.

[0063] In a second aspect, an embodiment of the present application provides a battery, which includes the battery cell provided by the embodiment of the first aspect.

[0064] In the above technical solutions, the cycle performance provided by the embodiment of the first aspect is good, and the battery equipped with the battery cell has good cycle performance.

[0065] In a third aspect, an embodiment of the present application provides an electrical device, which includes the battery cell provided in the embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0067] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0068] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0069] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0070] FIG4 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0071] FIG5 is a schematic diagram of the cooperation between the insulating body and the second wall portion provided by some embodiments of the present application (the restraining portion is not bent relative to the insulating body);

[0072] FIG6 is a schematic structural diagram of an electrode assembly provided in some embodiments of the present application;

[0073] FIG7 is a schematic diagram of a state in which the insulating body and the second wall portion are engaged with each other and the restraining portion is not bent relative to the insulating body, according to some embodiments of the present application;

[0074] FIG8 is a schematic diagram of a state in which the insulating body and the second wall portion cooperate with each other and the restraining portion is bent relative to the insulating body, according to some embodiments of the present application;

[0075] FIG9 is a schematic diagram of a state in which the insulating body and the second wall portion cooperate with each other and the restraining portion is bent relative to the insulating body, according to other embodiments of the present application;

[0076] FIG10 is a schematic diagram of a state in which the insulating body and the second wall portion are engaged with each other and the restraining portion is not bent relative to the insulating body, according to some further embodiments of the present application;

[0077] FIG11 is a schematic diagram of a state in which the insulating body and the second wall are engaged with each other and the restraining portion is not bent relative to the insulating body, and the restraining portion and the insulating body are not locked by the locking structure, according to some other embodiments of the present application;

[0078] FIG12 is a cross-sectional view taken along line A1-A1 in FIG11 ;

[0079] FIG13 is a schematic diagram showing a state in which the insulating body and the second wall portion in FIG11 are matched and the binding portion is bent relative to the insulating body, and the binding portion and the insulating body are locked by the locking structure;

[0080] FIG14 is a cross-sectional view taken along line A2-A2 in FIG13 ;

[0081] FIG15 is a schematic structural diagram of a second locking portion provided in some embodiments of the present application;

[0082] FIG16 is a schematic structural diagram of a second locking portion provided in other embodiments of the present application;

[0083] FIG17 is a schematic diagram of a state in which the insulating body and the second wall are engaged with each other and the restraining portion is not bent relative to the insulating body, and the restraining portion and the insulating body are not locked by the locking structure, according to some other embodiments of the present application;

[0084] FIG18 is a cross-sectional view taken along line A3-A3 in FIG17 ;

[0085] FIG19 is a cross-sectional view of a state in which the insulating body and the second wall are engaged with each other and the binding portion is not bent relative to the insulating body, and the binding portion and the insulating body are not locked by the locking structure, according to some other embodiments of the present application;

[0086] FIG20 is a schematic structural diagram of the insulating body and the restraining portion in FIG19 being locked by the locking structure.

[0087] Icons: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-housing; 211-first wall; 212-second wall; 213-opening; 214-housing; 215-end cover; 221-insulating body; 2211-avoidance hole; 222-binding portion; 2221-rest section; 22211-rest end; 22212-first surface; 2222-extension section; 22221-second surface; 223-second bending portion; 2232-through hole; 224-locking structure; 2241-first locking portion; 22411-locking hole; 22412-third guide surface; 22413-first hole section; 22414-second hole section; 22415-platform Step surface; 2242-second locking portion; 22421-first elastic portion; 224211-first limiting portion; 224212-first body; 224213-first guide surface; 22422-second elastic portion; 224221-second limiting portion; 224222-second body; 224223-second guide surface; 23-electrode assembly; 23a-pole piece; 231-main body; 232-pole ear; 233-first pole ear; 2331-first pole ear root; 2332-first bending portion; 2333-first connecting portion; 2334-concave surface; 24-electrode terminal; 25-current collecting component; 200-controller; 300-motor; X-first direction; Y-second direction; Z-third direction; A-center plane; B-first position. DETAILED DESCRIPTION

[0088] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0089] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0090] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0091] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0092] In the description of the embodiments of the present application, it should be noted that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are merely for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present application. In addition, the terms "first," "second," "third," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0093] The term "plurality" used in this application refers to two or more (including two).

[0094] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0095] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0096] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0097] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0098] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0099] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0100] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0101] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0102] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0103] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. may be used. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0104] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0105] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0106] As an example, the negative electrode active material may adopt the negative electrode active material for the battery cell 20 that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0107] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0108] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0109] In some embodiments, the separator is a separator membrane. There are many types of separator membranes, and any known separator membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0110] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0111] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0112] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0113] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0114] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0115] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0116] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0117] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0118] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0119] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0120] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0121] In some embodiments, the electrode assembly is a laminate structure.

[0122] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0123] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0124] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0125] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0126] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0127] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0128] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0129] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0130] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include but are not limited to square-shell, blade-shaped, and polygonal batteries, such as hexagonal batteries.

[0131] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0132] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0133] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0134] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body 10 can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0135] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0136] Batteries, with their outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient, are a vital component of today's new energy development. The development of battery technology requires simultaneous consideration of multiple design factors, including performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must be considered.

[0137] In battery technology, a battery cell includes a shell and an electrode assembly. The electrode assembly is housed in the shell. After the electrode assembly is placed in the shell, the electrode tabs of the electrode assembly will bend. After the tabs of the electrode assembly closest to the wall of the shell in the stacking direction of the electrode assembly are bent, the gap between the electrode sheets closer to the wall of the electrode assembly closest to the wall may increase, resulting in poor cycle performance of the battery cell.

[0138] Based on the above considerations, in order to alleviate the problem that the gap between the pole pieces increases due to the bending of the pole pieces, resulting in the deterioration of the cycle performance of the battery cell, an embodiment of the present application provides a battery cell, the battery cell includes a shell, a restraining portion and at least one electrode assembly; the shell has a first wall portion; the electrode assembly is accommodated in the shell, the electrode assembly includes pole pieces stacked along a first direction, the pole pieces and the first wall portion are stacked along the first direction, the electrode assembly includes a main body and pole pieces, and the main body is provided with pole pieces in at least one section along the second direction, and the first direction and the second direction intersect; the restraining portion is arranged in the shell; wherein, along the first direction, the pole piece of the electrode assembly closest to the first wall portion is the first pole piece, and the restraining portion is at least partially located between the first pole piece and the first wall portion, and abuts against the surface of the first pole piece facing the first wall portion.

[0139] The outer shell of the battery cell has a first wall portion arranged along the first direction with the pole piece, and the restraining portion abuts against the side of the first pole ear of the electrode assembly closest to the first wall portion facing the first wall portion, providing a restraining force for the first pole ear, reducing the gap between the layers of the first pole ear, thereby reducing the gap between the pole piece main body areas connected to the first pole ear, so that the gap between the pole pieces on the side close to the first wall portion of the electrode assembly closest to the first wall portion is smaller, which is beneficial to improving the cycle performance of the battery cell.

[0140] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be constructed, thereby alleviating the problem of increased gaps between electrode sheets caused by bent tabs after the electrode assembly is placed in the housing, and improving the cycle performance of the battery cells.

[0141] The embodiments of the present application provide an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0142] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0143] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source or a power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0144] In some embodiments of the present application, the battery 100 can not only serve as the operating power source or usage power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0145] 2 and 3 , FIG2 is an exploded view of a battery 100 according to some embodiments of the present invention, and FIG3 is a schematic structural diagram of a battery cell 20 according to some embodiments of the present invention. The battery 100 includes a housing 10 and a battery cell 20 , wherein the battery cell 20 is accommodated in the housing 10 .

[0146] The housing 10 is used to provide assembly space for the battery cells 20 and can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 cover each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure. The first housing body 11 covers the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, and the open side of the first housing body 11 covers the open side of the second housing body 12.

[0147] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube, etc. For example, in FIG2 , the box body 10 is in the shape of a cuboid.

[0148] In the battery 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations within the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10.

[0149] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20 .

[0150] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be a rectangular parallelepiped, a cylinder, a prism, or other shapes. For example, in FIG3 , the battery cell 20 is a rectangular parallelepiped.

[0151] As shown in Figures 3, 4, and 5, in some embodiments, the battery cell 20 includes a housing 21, a restraining portion 222, and at least one electrode assembly 23; the housing 21 has a first wall 211; the electrode assembly 23 is accommodated in the housing 21, and the electrode assembly 23 includes electrode sheets 23a stacked along a first direction X, and the electrode sheets 23a and the first wall 211 are arranged along the first direction X. The electrode assembly 23 includes a main body 231 and a pole lug 232, and the pole lug 232 is provided at least at one end of the main body 231 along a second direction Y. The first direction X and the second direction Y intersect; the restraining portion 222 is disposed in the housing 21; wherein, along the first direction X, the pole lug 232 of the electrode assembly 23 closest to the first wall 211 is the first pole lug 233, and the restraining portion 222 is at least partially located between the first pole lug 233 and the first wall 211, and abuts against the surface of the first pole lug 233 facing the first wall 211.

[0152] The housing 21 has a receiving space formed therein for receiving the electrode assembly 23. The receiving space can also be used to receive an electrolyte, which can be an electrolyte solution.

[0153] The outer shell 21 includes a shell 214 and an end cover 215. A accommodating cavity is formed inside the shell 214, which is used to accommodate the electrode assembly 23, and the accommodating cavity has at least one opening 213. That is, the shell 214 is a hollow structure with an opening 213 at at least one end. The end cover 215 covers the opening 213 of the shell 214 and forms a sealed connection to form a accommodating space for accommodating the electrode assembly 23 and the electrolyte.

[0154] When assembling the battery cell 20 , the electrode assembly 23 may be placed in the housing 214 first, and the housing 214 may be filled with electrolyte. The end cap 215 may then be placed on the opening 213 of the housing 214 to complete the assembly of the battery cell 20 .

[0155] The first wall portion 211 may be a wall portion of the housing 214 , for example, the first wall portion 211 is a side wall of the housing 214 .

[0156] The shell 214 can be in various shapes, such as a cylinder, a rectangular parallelepiped, or a prismatic structure. The shape of the shell 214 can be determined according to the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a cylindrical structure, a shell 214 with a cylindrical structure can be selected; if the electrode assembly 23 is a rectangular parallelepiped structure, a shell 214 with a rectangular parallelepiped structure can be selected. Of course, the structure of the end cap 215 can also be various, for example, the end cap 215 is a plate-like structure or a hollow structure with one end open. For example, in Figure 3, the shell 214 is a rectangular parallelepiped structure, the first direction X is the length direction of the battery cell 20, and the second direction Y is the height direction of the battery cell 20.

[0157] Of course, it is understandable that the shell 21 is not limited to the above structure. The shell 21 may also be other structures. For example, the shell 21 may include a shell body 214 and two end covers 215. The shell body 214 is a hollow structure with openings 213 formed at both opposite ends. One end cover 215 corresponds to an opening 213 of the shell body 214 and forms a sealed connection to form a storage space for accommodating the electrode assembly 23 and the electrolyte. That is, the shell body 214 has openings 213 formed on both opposite sides, and the two end covers 215 are respectively covered on both sides of the shell body 214 to close the corresponding openings 213.

[0158] The housing 21 may be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0159] The electrode sheet 23a of the electrode assembly 23 includes a positive electrode sheet and a negative electrode sheet. The electrode assembly 23 also includes a separator (not shown) that is used to separate the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the negative electrode sheet, and the separator are stacked in a certain order to form a laminated electrode assembly. The positive electrode sheet, the negative electrode sheet, and the separator are stacked in a certain order and wound to form a wound electrode assembly.

[0160] It should be noted that one tab 232 of the electrode assembly 23 can be a component formed by mutually stacking and connecting multiple tab sheets formed on the area of ​​the positive electrode sheet not coated with the positive electrode active material layer to form a positive tab 232, that is, one positive tab can be a structure formed by stacking multiple tab sheets formed on the area of ​​the positive electrode collector not coated with the positive electrode active material layer, and another tab 232 can be a component formed by mutually stacking and connecting multiple tab sheets formed on the area of ​​the negative electrode sheet not coated with the negative electrode active material layer to form a negative tab 232, that is, one negative tab can be a structure formed by stacking multiple tab sheets formed on the area of ​​the negative electrode collector not coated with the negative electrode active material layer.

[0161] The area of ​​the positive electrode sheet coated with the positive electrode active site layer, the area of ​​the negative electrode sheet coated with the negative electrode active material layer, and at least a portion of the separator of the electrode assembly 23 form the main body 231 of the electrode assembly 23. A tab 232 is provided at one end of the main body 231 along the second direction Y. Each electrode assembly 23 has two tabs 232 of opposite polarity. These two tabs 232 of opposite polarity can be provided at the same end of the main body 231 along the second direction Y and spaced apart along the third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0162] In other embodiments, two tabs 232 with opposite polarities may also be disposed at opposite ends of the main body 231 along the second direction Y.

[0163] In some embodiments, the battery cell 20 further includes an electrode terminal 24 . The electrode terminal 24 may be insulated and mounted on the housing 21 , and the electrode terminal 24 is electrically connected to the electrode assembly 23 to output or input electrical energy to the battery cell 20 .

[0164] It should be noted that the electrode terminal 24 is insulated and mounted on the housing 21 , that is, no electrical connection is formed between the electrode terminal 24 and the housing 21 .

[0165] The battery cell 20 may include one or two electrode terminals 24. For example, as shown in FIG3 , the battery cell 20 includes two electrode terminals 24, which are spaced apart along the length of the battery cell 20. Each electrode assembly 23 has two tabs 232, which are spaced apart along the length of the battery cell 20. The two tabs 232 have opposite polarities, and the two electrode terminals 24 are electrically connected to the two tabs 232 of the electrode assembly 23, respectively, to enable input or output of the positive and negative electrodes of the battery cell 20.

[0166] Exemplarily, the electrode terminal 24 may be made of a variety of materials. For example, the electrode terminal 24 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0167] There are many locations where the electrode terminals 24 are installed on the outer shell 21. For example, in Figure 3, both electrode terminals 24 are installed on the end cover 215 of the outer shell 21. Of course, the structure of the battery cell 20 is not limited to this. In the embodiment where the battery cell 20 includes two electrode terminals 24, both electrode terminals 24 can also be installed on the shell 214 of the outer shell 21. Similarly, the two electrode terminals 24 can also be one electrode terminal 24 installed on the shell 214 of the outer shell 21, and the other electrode terminal 24 installed on the end cover 215 of the outer shell 21. The wall portion of the outer shell 21 where the electrode terminals 24 are installed is the second wall portion 212. The thickness direction of the battery cell 20, the height direction of the battery cell 20, and the length direction of the battery cell 20 are perpendicular to each other.

[0168] In some embodiments, as shown in Figure 3, the battery cell 20 may also include two current collecting components 25. The two current collecting components 25 are both arranged in the outer shell 21 and are spaced apart along the length direction of the battery cell 20. Each current collecting component 25 is used to connect an electrode terminal 24 and a plurality of electrode assemblies 23 with the same polarity in the tabs 232 to achieve electrical connection between the electrode terminal 24 and the electrode assembly 23, which is conducive to reducing the difficulty of assembly between the tabs 232 and the electrode terminal 24.

[0169] Exemplarily, the material of the current collecting member 25 may be various, for example, the material of the current collecting member 25 may be copper, iron, aluminum, steel or aluminum alloy.

[0170] The battery cell 20 may include one electrode assembly 23 or may include multiple electrode assemblies 23. The multiple electrode assemblies 23 may be arranged along a first direction X. In embodiments where the battery cell 20 includes multiple electrode assemblies 23, the multiple electrode assemblies 23 are arranged along the first direction X. The first direction X may be parallel to the thickness direction of the electrode assembly 23. In embodiments where the electrode assembly 23 has a wound structure, the electrode assembly 23 includes a bending region and a straight region, and the straight region is provided with a bending region at both ends along the third direction Z. The electrode piece 23a and the first wall portion 211 are stacked along the first direction X, which means that the electrode piece 23a in the straight region and the first wall portion 211 are stacked along the first direction X. The first direction X, the second direction Y, and the third direction Z may be perpendicular to each other. In embodiments where the electrode assembly 23 has a wound structure, the second direction Y may be parallel to the winding axis direction of the electrode assembly 23.

[0171] The first direction X may be parallel to the thickness direction of the battery cell 20, and the first direction X is parallel to the thickness direction of the first wall portion 211. In an embodiment where the battery cell 20 includes multiple electrode assemblies 23, along the first direction X, the tab 232 of the electrode assembly 23 closest to the first wall portion 211 among all the electrode assemblies 23 is the first tab 233.

[0172] The restraining portion 222 is disposed in the housing 21. The restraining portion 222 can be disposed on the electrode assembly 23 or on the housing 21. The restraining portion 222 is made of plastic, silicone, and the like.

[0173] The outer shell 21 of the battery cell 20 has a first wall portion 211 arranged along the first direction X with the pole piece 23a, and the restraining portion 222 abuts against the side of the first pole ear 233 of the electrode assembly 23 facing the first wall portion 211 closest to the first wall portion 211 of the outer shell 21, providing a restraining force for the first pole ear 233, reducing the gap between the layers of the first pole ear 233, thereby reducing the gap between the pole piece main body areas connected to the first pole ear 233, so that the gap between the pole pieces on the side close to the first wall portion 211 of the electrode assembly 23 closest to the first wall portion 211 is smaller, which is beneficial to improving the cycle performance of the battery cell 20.

[0174] It should be noted that the electrode main body area refers to the area of ​​the electrode having the active material layer.

[0175] In some embodiments, the electrode assembly 23 closest to the first wall portion 211 along the first direction X has a center plane A perpendicular to the first direction X, and the first electrode tab 233 is at least partially disposed on a side of the center plane A close to the first wall portion 211 .

[0176] In an embodiment in which the electrode assembly 23 has a wound structure, the center plane A of the electrode assembly 23 closest to the first wall portion 211 along the first direction X may be a plane passing through the winding axis of the electrode assembly 23 and perpendicular to the first direction X. In an embodiment in which the electrode assembly 23 has a laminated structure, the center plane A of the electrode assembly 23 closest to the first wall portion 211 along the first direction X may be a plane in which the electrode assembly 23 is located in the middle of the electrode assembly 23 in the first direction X.

[0177] The first pole ear 233 is at least partially arranged on the side of the center plane A of the electrode assembly 23 closest to the first wall portion 211 close to the first wall portion 211, and the binding portion 222 and the surface of the first pole ear 233 located on the side of the center plane A facing the first wall portion 211 partially abut against the first wall portion 211, so that the binding portion 222 and the first pole ear 233 are more easily abutted, and the binding portion 222 provides a binding force for the first pole ear 233, which is beneficial to reducing the gap between the layers of the first pole ear 233, thereby reducing the gap between the pole piece main body areas connected to the first pole ear 233, so that the gap between the pole pieces 23a on the side close to the first wall portion 211 of the electrode assembly 23 closest to the first wall portion 211 is smaller, which is beneficial to improving the cycle performance of the battery cell 20.

[0178] The first electrode tab 233 may be entirely disposed on the side of the electrode assembly 23 closest to the first wall portion 211, with the center plane A facing the first wall portion 211. Alternatively, a portion of the first electrode tab 233 may be disposed on the side of the electrode assembly 23 closest to the first wall portion 211, with the center plane A facing the first wall portion 211, and another portion of the first electrode tab 233 may be disposed on the side of the electrode assembly 23 closest to the first wall portion 211, with the center plane A facing away from the first wall portion 211.

[0179] In some embodiments, along the first direction X, there is a distance between the first wall portion 211 and the main body portion 231 of the electrode assembly 23 closest to the first wall portion 211 .

[0180] It can be understood that along the first direction X, there is a distance between the first wall portion 211 and the main body 231 of the electrode assembly 23 closest to the first wall portion 211, and the surfaces of the first wall portion 211 and the main body 231 of the electrode assembly 23 closest to the first wall portion 211 are not in direct contact. There is a space between the first wall portion 211 and the main body 231 of the electrode assembly 23 closest to the first wall portion 211. The space between the first wall portion 211 and the main body 231 of the electrode assembly 23 closest to the first wall portion 211 can only have gas, such as air, or the space between the first wall portion 211 and the main body 231 of the electrode assembly 23 closest to the first wall portion 211 along the first direction X can be filled with other substances, such as electrolyte, buffer foam, etc.

[0181] Along the first direction X, there is a distance between the first wall portion 211 and the main body portion 231 of the electrode assembly 23 closest to the first wall portion 211, providing expansion space for the electrode assembly 23, reducing the risk of explosion, fire and other problems in the battery cell 20, and improving the reliability of the battery cell 20.

[0182] As shown in Figure 4, in some embodiments, the first pole tab 233 includes a plurality of pole tab sheets stacked along the first direction X, and the connection position between the main body 231 and the pole tab sheet closest to the first wall portion 211 among the plurality of pole tab sheets of the first pole tab 233 is the first position B; the restraining portion 222 has a resting end 22211 resting against the first pole tab 233, and along the first direction X, the distance between the end of the resting end 22211 away from the first wall portion 211 and the first wall portion 211 is greater than the distance between the first position B and the first wall portion 211.

[0183] It should be noted that in an embodiment of a structure in which the pole tab 232 is formed by stacking multiple pole tab sheets in an area of ​​the current collector that is not coated with an active material layer, the first position B is the position where the pole tab sheet closest to the first wall portion 211 in the first direction X among the multiple pole tab sheets forming the first pole tab 233 is connected to the main body portion 231.

[0184] As shown in FIG4 , along the first direction X, the distance between the end of the abutting end 22211 away from the first wall portion 211 and the first wall portion 211 is H1 , and the distance between the first position B and the first wall portion 211 is H2 , where H1>H2 .

[0185] Along the first direction X, the distance between the end portion 22211 of the restraining portion 222 away from the first wall portion 211 and the first wall portion 211 is greater than the distance between the first position B and the first wall portion 211, so that the restraining portion 222 can squeeze the first pole ear 233 in the first direction X along the direction away from the first wall portion 211, thereby reducing the gap between the layers of the first pole ear 233, thereby reducing the gap between the pole piece main body areas connected to the first pole ear 233, so that the gap between the pole pieces 23a on the side close to the first wall portion 211 of the electrode assembly 23 closest to the first wall portion 211 is smaller, which is beneficial to improving the cycle performance of the battery cell 20.

[0186] In some embodiments, the surface on which the abutting end 22211 abuts against the first electrode tab 233 is an arc surface.

[0187] The surface of the abutting end 22211 abutting against the first tab 233 can be an arc surface. The radius of the surface of the abutting end 22211 abutting against the first tab 233 can be designed according to actual requirements, for example, the radius of the surface of the abutting end 22211 abutting against the first tab 233 is 1 mm.

[0188] The surface on which the abutting end 22211 abuts against the first electrode tab 233 is an arc surface, which can reduce the risk of damaging or destroying the first electrode tab 233 when the abutting end 22211 abuts against the first electrode tab 233 .

[0189] As shown in Figures 4 and 6, in some embodiments, the shell 21 has a second wall portion 212, the second wall portion 212 and the pole ear 232 are arranged along the second direction Y, the battery cell 20 includes an electrode terminal 24, and the electrode terminal 24 is arranged on the second wall portion 212; the first pole ear 233 includes a first pole ear root portion 2331, a first bending portion 2332 and a first connecting portion 2333, the first pole ear root portion 2331 is connected to the main body portion 231, the first bending portion 2332 connects the first pole ear root portion 2331 and the first connecting portion 2333, and the first connecting portion 2333 is electrically connected to the electrode terminal 24; the binding portion 222 is against the surface of the first pole ear root portion 2331 facing the first wall portion 211.

[0190] The second wall portion 212 may be an end cap 215 . In an embodiment where the housing 21 includes a shell 214 and two end caps 215 , one of the two end caps 215 may be the second wall portion 212 , and the first wall portion 211 may be a side wall of the shell 214 .

[0191] The first tab root 2331 is the portion of the first tab 233 that connects to the main portion of the corresponding tab 23a. Along the second direction Y, the first tab root 2331 is the portion of the first tab 233 closest to the main portion. The first bend 2332 is the area where the first tab 233 bends. The first connecting portion 2333 is the portion formed after the first tab 233 is bent. Along the second direction Y, the first connecting portion 2333 is the portion of the first tab 233 farthest from the main portion. In other words, the first connecting portion 2333 is the portion of the first tab 233 closest to the second wall 212. The first connecting portion 2333 can be directly connected to the electrode terminal 24, thereby electrically connecting the first connecting portion 2333 and the electrode terminal 24. Alternatively, the first connecting portion 2333 can be indirectly connected to the electrode terminal 24, such as by being electrically connected to the electrode terminal 24 through the current collecting member 25.

[0192] The restraining portion 222 abuts against the surface of the first electrode tab root 2331 facing the first wall portion 211 , and the restraining force of the restraining portion 222 on the first electrode tab 233 acts on the first electrode tab root 2331 .

[0193] The restraining portion 222 abuts against the surface of the first pole ear root 2331 facing the first wall portion 211, so that the abutting position of the restraining portion 222 against the first pole ear 233 is closer to the pole piece main body area connected to the first pole ear 233, thereby better restraining the pole piece main body area, which is more conducive to reducing the gap between the pole pieces on the side close to the first wall portion 211 of the electrode assembly 23 closest to the first wall portion 211, which is beneficial to improving the cycle performance of the battery cell 20.

[0194] In other embodiments, the binding portion 222 may also abut against other positions of the surface of the first tab 233 facing the first wall portion 211 , such as the binding portion 222 abutting against the surface of the first bending portion 2332 facing the first wall portion 211 .

[0195] In some embodiments, the battery cell 20 further includes an insulating layer (not shown in the figures), which is at least partially disposed on the surface of the first tab root 2331 .

[0196] The surface of each of the formed first electrode tabs 233 in the area not coated with the active material layer may be provided with an insulating layer, or only the surface of the area of ​​the formed first electrode tab 233 not coated with the active material layer and closest to the first wall portion 211 among the multiple areas stacked along the first direction X may be provided with an insulating layer.

[0197] In an embodiment where the insulating layer is at least partially disposed on the surface of the first pole ear root 2331, the restraining portion 222 can directly abut against the surface of the first pole ear root 2331 facing the first wall portion 211, thereby achieving direct abutment between the restraining portion 222 and the first pole ear root 2331. The restraining portion 222 can also abut against the insulating layer, thereby achieving indirect abutment between the restraining portion 222 and the surface of the first pole ear root 2331.

[0198] The insulating layer may be entirely disposed on the surface of the first tab root 2331. Alternatively, a portion of the insulating layer may be disposed on the surface of the first tab root 2331, and another portion disposed on the main body 231. Alternatively, a portion of the insulating layer may be disposed on the surface of the first tab root 2331, another portion disposed on the main body 231, and another portion disposed on the surface of other locations of the first tab 233, such as the surface of the first bend 2332 of the first tab 233.

[0199] The insulating layer may be made of a ceramic coating, a rubber layer, or the like.

[0200] The battery cell 20 further includes an insulating layer at least partially disposed on the surface of the first electrode tab root 2331 , which helps to improve the strength of the first electrode tab 233 and reduce the risk of the first electrode tab 233 being torn.

[0201] As shown in Figures 4, 5, 7, and 8, in some embodiments, the restraining portion 222 includes a rest section 2221 and an extension section 2222. The extension section 2222 is at least partially located between the first pole ear 233 and the first wall portion 211. Along the direction of the pole ear 232 pointing to the main body portion 231, the rest section 2221 protrudes from one end of the extension section 2222, and the rest section 2221 rests against the root portion 2331 of the first pole ear.

[0202] Along the direction from the tab 232 to the main body 231, the abutting section 2221 protrudes from one end of the extension section. Along the third direction Z, the abutting section 2221 is smaller than the extension section 2222. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The third direction Z can be parallel to the length of the battery cell 20. The abutting section 2221 abuts against the surface of the first tab base 2331 facing the first wall 211.

[0203] The binding portion 222 includes a rest section 2221 and an extension section 2222. The extension section 2222 is at least partially located between the first pole ear 233 and the first wall portion 211. The rest section 2221 protrudes at one end and rests against the first pole ear root 2331, which can reduce the space occupied by the binding portion 222, facilitate the rest against the first pole ear 233, and reduce the risk of interference between the first pole ear 233 and the binding portion 222.

[0204] In some embodiments, the abutting section 2221 protrudes from the extending section 2222 in the first direction X along a direction away from the first wall portion 211 .

[0205] Along the first direction X, the surface of the abutting section 2221 facing the first wall portion 211 may be coplanar with the surface of the extending section 2222 facing the first wall portion 211. Along the first direction X, the distance between the surface of the abutting section 2221 facing away from the first wall portion 211 and the first wall portion 211 is greater than the distance between the surface of the extending section 2222 facing away from the first wall portion 211 and the first wall portion 211, so that the abutting section 2221 protrudes beyond the extending section 2222 in the first direction X in a direction away from the first wall portion 211.

[0206] The abutting section 2221 protrudes from the extending section 2222 in the first direction X away from the first wall portion 211 , so that the abutting section 2221 is closer to the first electrode tab 233 in the first direction X, making it easier for the abutting section 2221 to abut against the first electrode tab 233 .

[0207] In some embodiments, the electrode assembly 23 closest to the first wall portion 211 along the first direction X has a center plane A perpendicular to the first direction X, and the first bending portion 2332 is located on the side of the center plane A facing the first wall portion 211 .

[0208] It can be understood that the multiple tab pieces forming the first tab 233 are gathered together and then bent toward the first wall portion 211, so as to form a first bent portion 2332 on the side of the center plane A of the electrode assembly 23 closest to the first wall portion 211 facing the first wall portion 211. It can also be understood that the multiple tab pieces forming the first tab 233 are gathered together in a direction close to the first wall portion 211 and bent in a direction close to the first wall portion 211.

[0209] The first bending portion 2332 of the first pole ear 233 is located on the side of the electrode assembly 23 closest to the first wall portion 211, with the center surface A facing the first wall portion 211. It can be understood that the multiple pole ear pieces of the first pole ear 233 gather in the direction close to the first wall portion 211, reducing the distance between the surface of the first pole ear 233 facing the first wall portion 211 and the first wall portion 211, thereby facilitating the abutment between the binding portion 222 and the first pole ear 233.

[0210] The abutting section 2221 abuts the first tab root 2331, and any position of the abutting section 2221 may abut the first tab root 2331. For example, the surface of the abutting section 2221 facing the first tab 233 abuts the first tab root 2331. For another example, in some embodiments, the restraining portion 222 includes an extension section 2222 and an abutting section 2221. The abutting section 2221 bends from the extension section 2222 toward the first tab 233, and the end of the abutting section 2221 away from the extension section 2222 forms an abutting end 22211, which abuts the first tab root 2331.

[0211] The abutting end 22211 is the end of the abutting section 2221 away from the extension section 2222. The abutting section 2221 is bent toward the first pole tab 233. It can be understood that the abutting section 2221 is bent along the curve from the extension section 2222 toward the first pole tab 233 to form a hook-shaped abutting section 2221, and the hook portion of the hook-shaped structure is facing the first pole tab 233.

[0212] The abutting section 2221 bends toward the direction approaching the first pole tab 233, facilitating the abutting section 2221 against the first pole tab 233. The abutting section 2221 bends toward the direction approaching the first pole tab 233, so that the end of the abutting section 2221 away from the extension section 2222 forms an abutting end 22211 against the root portion 2331 of the first pole tab. That is, the end of the abutting section 2221 away from the extension section 2222 abuts against the root portion 2331 of the first pole tab, which not only provides better binding force for the first pole tab 233, but also reduces the risk of excessive contact area between the first pole tab 233 and the abutting section 2221, thereby interfering with the connection between the first pole tab 233 and other structures.

[0213] As shown in Figures 7 and 8, in some embodiments, the end of the abutting section 2221 away from the extension section 2222 forms an abutting end 22211, and the abutting end 22211 abuts against the first pole ear 233. The abutting section 2221 has a first surface 22212 facing the first pole ear 233, and the first surface 22212 extends to the abutting end 22211. The first surface 22212 is an arc surface.

[0214] The abutting section 2221 is bent toward the first tab 233 so that the abutting section 2221 forms an arcuate surface facing the first surface 22212 of the first tab 233. For example, the radius of the arcuate surface can be 1 mm. The abutting end 22211 can abut against the surface of the first tab root 2331 of the first tab 233 facing the first wall portion 211.

[0215] The end of the abutting section 2221 away from the extension section 2222 forms an abutting end 22211 that abuts the first pole tab 233. That is, the end of the abutting section 2221 away from the extension section 2222 can abut the first pole tab 233, which not only provides better binding force for the first pole tab 233, but also reduces the risk of excessive contact area between the first pole tab 233 and the abutting section 2221, thereby interfering with the connection between the first pole tab 233 and other structures. The first surface 22212 is a curved surface, which facilitates the formation of a structure in which the abutting section 2221 bends toward the first pole tab 233, facilitating the manufacturing and molding of the abutting section 2221 and facilitating the abutment of the abutting section 2221 against the first pole tab 233.

[0216] As shown in Figure 9, in some embodiments, the extension section 2222 has a second surface 22221 facing the first pole ear 233, the first surface 22212 is connected to the second surface 22221, and the distance between the second surface 22221 and the first wall portion 211 in the first direction X gradually increases along the direction of the pole ear 232 pointing to the main body portion 231.

[0217] As the tab 232 points toward the main body 231, the distance between the second surface 22221 and the first wall 211 in the first direction X gradually increases. The second surface 22221 may be a curved surface, an inclined surface, or the like. As shown in FIG9 , the second surface 22221 is an inclined surface. As the second wall 212 points toward the main body 231, the second surface 22221 gradually slopes away from the first tab 233 and extends to the end of the first surface 22212 away from the abutting end 22211.

[0218] The extension section 2222 has a second surface 22221 facing the first pole tab 233. Along the direction from the pole tab to the main body 231, the distance between the second surface 22221 and the first wall in the first direction X gradually increases, reducing the risk of the extension section 2222 over-extruding the first pole tab 233 and causing the first pole tab 233 to crack.

[0219] In some embodiments, the electrode assembly 23 closest to the first wall portion 211 includes a plurality of first pole ears 233, and the plurality of first pole ears 233 are arranged along the third direction Z; the extension section 2222 is provided with a plurality of abutment sections 2221, and the plurality of abutment sections 2221 are arranged at intervals along the third direction Z, and one first pole ear 233 corresponds to at least one abutment section 2221, and the first direction X, the second direction Y and the third direction Z are not coplanar and intersect with each other.

[0220] In this embodiment, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0221] The electrode assembly 23 closest to the first wall portion 211 includes a plurality of first pole tabs 233 spaced apart along the third direction Z. One end of the extension section 2222 is provided with a plurality of abutting sections 2221 spaced apart along the third direction Z. The abutting sections 2221 and the first pole tabs 233 are arranged in a one-to-one correspondence.

[0222] In this embodiment, as shown in Figures 3 and 5, each electrode assembly 23 includes two electrode tabs 232 spaced apart along the third direction Z. The electrode assembly 23 closest to the first wall portion 211 includes two first electrode tabs 233 spaced apart along the third direction Z. One end of the extension section 2222 is provided with two abutting sections 2221 spaced apart along the third direction Z. The two abutting sections 2221 respectively abut against the surfaces of the two first electrode tabs 233 facing the first wall portion 211.

[0223] In other embodiments, the electrode assembly 23 closest to the first wall portion 211 includes three or more first pole ears 233 arranged at intervals along the third direction Z, and one end of the extension segment 2222 is provided with three or more abutment segments 2221 arranged at intervals along the third direction Z.

[0224] The electrode assembly 23 closest to the first wall portion 211 includes multiple first pole tabs 233 . The extension section 2222 is provided with multiple abutting sections 2221 . Each abutting section 2221 abuts against a first pole tab 233 , thereby providing better binding force for each first pole tab 233 .

[0225] In other embodiments, one abutting section 2221 may abut against the surfaces of multiple first electrode tabs 233 facing the first wall portion 211 at the same time.

[0226] In some embodiments, the shell 21 has a second wall portion 212, the second wall portion 212 and the first wall portion 211 are adjacently arranged and connected, and the second wall portion 212 and the pole ear 232 are arranged along the second direction Y; the battery cell 20 also includes an insulating body 221, the insulating body 221 is arranged on the side of the pole ear 232 facing the second wall portion 212 to insulate and isolate the second wall portion 212 and the pole ear 232, and the binding portion 222 is connected to the insulating body 221.

[0227] The battery cell 20 includes an insulating body 221. The insulating body 221 is arranged on the side of the tab 232 away from the main body 231. The insulating body 221 is located between the second wall portion 212 and the tab 232 to insulate and separate the tab 232 from the second wall portion 212. In this embodiment, the end cover 215 of the shell 21 is the second wall portion 212, and the insulating body 221 is located between the end cover 215 and the tab 232 to insulate and separate the end cover 215 from the tab 232. In the embodiment where the electrode terminal 24 is arranged on the end cover 215, the insulating body 221 avoids the arrangement of the electrode terminal 24. As shown in Figures 4 and 5, the insulating body 221 is provided with an avoidance hole 2211, and the electrode terminal 24 is electrically connected to the tab 232 through the avoidance hole 2211. In some embodiments, the insulating body 221 can also be referred to as lower plastic.

[0228] In the embodiment where the restraining portion 222 includes an extension section 2222 and a contact section 2221, the insulating body 221 is connected to one end of the extension section 2222 along the second direction Y, and the contact section 2221 is connected to the other end of the extension section 2222 along the second direction Y. That is, the contact section 2221 is connected to a section of the extension section 2222 away from the insulating body 221 along the second direction Y. The dimension of the extension section 2222 along the third direction Z can be the same as the dimension of the insulating body 221 along the third direction Z.

[0229] One end of the extending section 2222 away from the insulating body 221 is provided with two abutting sections 2221 spaced apart along the third direction Z. The two abutting sections 2221 respectively abut against surfaces of the two first tabs 233 facing the first wall portion 211 .

[0230] In other embodiments, the electrode assembly 23 closest to the first wall portion 211 includes three or more first pole ears 233 arranged at intervals along the third direction Z, and the end of the extension section 2222 away from the insulating body 221 is provided with three or more abutment sections 2221 arranged at intervals along the third direction Z.

[0231] The extension section 2222 can be directly connected to the insulating body 221 or indirectly connected to the insulating body 221. The extension section 2222 can partially extend along the second direction Y to between the first wall portion 211 and the first tab 233, thereby reducing the space occupied by the extension section 2222 between the first tab 233 and the first wall portion 211 and reducing the risk of the extension section 2222 interfering with the connection between the first tab 233 and other structures. The extension section 2222 can also extend entirely along the second direction Y to between the first wall portion 211 and the first tab 233.

[0232] The battery cell 20 further includes an insulating body 221 , which is disposed between the side of the tab 232 facing the second wall 212 and the second wall 212 to reduce the risk of internal short circuit in the battery cell 20 and improve the reliability of the battery cell 20 .

[0233] As shown in Figures 7, 8, and 9, in some embodiments, the restraining portion 222 includes an extension section 2222 and a rest section 2221, the extension section 2222 is at least partially located between the first pole ear 233 and the first wall portion 211, the rest section 2221 protrudes from one end of the extension section 2222, and the rest section 2221 rests against the first pole ear 233; the battery cell 20 also includes a second bending portion 223, which connects the insulating body 221 and the restraining portion 222.

[0234] One end of the second bending portion 223 is connected to the insulating body 221, and the other end of the second bending portion 223 is connected to the binding portion 222. When at least a portion of the binding portion 222 is located between the first wall portion 211 and the first pole lug 233, the second bending portion 223 is in an arc-shaped bending state. When the binding portion 222 is not located between the first wall portion 211 and the first pole lug 233, the second bending portion 223 can be in a straight line state (as shown in FIG7 ). As shown in FIG4 and FIG8 , the binding portion 222 is bent relative to the insulating body 221 at the second bending portion 223 around an axis parallel to the third direction Z, so that the second bending portion 223 is in an arc-shaped bending state, and the binding portion 222 can be located between the first wall portion 211 and the first pole lug 233 and abut against the surface of the first pole lug 233 facing the first wall portion 211.

[0235] The second bending portion 223 can be connected to any position of the binding portion 222 , for example, the second bending portion 223 is connected to the abutting section 2221 of the binding portion 222 , or the second bending portion 223 is connected to the extending section 2222 of the binding portion 222 .

[0236] The extension section 2222 can be directly connected to the insulating body 221, or indirectly connected to the insulating body 221. As shown in Figures 5, 7, 8, and 9, in some embodiments, the battery cell 20 further includes a second bent portion 223, which connects the insulating body 221 and the extension section 2222.

[0237] One end of the second bending section is connected to an edge of the insulating body 221 along the first direction X, and the other end of the second bending section is connected to an end of the extending section 2222 away from the abutting section 2221 .

[0238] The extension section 2222 and the insulating body 221 are indirectly connected via a second bend 223. The second bend 223 is an arc-shaped structure. In some embodiments, the tie portion 222 can be bent relative to the insulating body 221 at the second bend 223, so that the tie portion 222 can be located between the first tab 233 and the first wall portion 211, forming the second bend 223.

[0239] The insulating body 221 and the extension section 2222 are connected by the second bending portion 223 , so that the insulating body 221 and the restraining portion 222 can become one body, which can improve the stability of the insulating body 221 and the restraining portion 222 inside the battery cell 20 and thus improve the reliability of the insulating body 221 and the restraining portion 222 .

[0240] In some embodiments, the thickness of the insulating body 221 and the thickness of the extending section 2222 are both greater than the thickness of the second bent portion 223 .

[0241] The thickness of the insulating body 221 is the dimension of the insulating body 221 along the second direction Y. The thickness of the insulating body 221 may be the minimum thickness of the insulating body 221 along the second direction Y. The thickness of the extending section 2222 is the dimension of the extending section 2222 along the first direction X.

[0242] The thickness of the insulating body 221 and the thickness of the extension section 2222 are both greater than the thickness of the second bending portion 223, so the strength of the insulating body 221 and the strength of the extension section 2222 are both greater than the strength of the second bending portion 223, which facilitates the binding portion 222 to bend relative to the insulating body 221 at the second bending portion 223 to between the first wall portion 211 and the first pole ear 233.

[0243] The thickness of the insulating body 221 and the thickness of the extension section 2222 are both greater than the thickness of the second bending portion 223, so that the strength of the insulating body 221 and the strength of the extension section 2222 are both greater than the strength of the second bending portion, which facilitates the extension section 2222 to be bent and formed relative to the insulating body 221 at the second bending portion 223, thereby facilitating the insulating body 221 and the binding portion 222 to form an integral structure.

[0244] In some embodiments, the thickness of the abutting section 2221 may be greater than the thickness of the second bent portion 223 to increase the strength of the abutting section 2221 and facilitate the abutting section 2221 to better bind the first electrode tab 233 .

[0245] As shown in FIG. 10 , in some embodiments, the second bending portion 223 is provided with a through hole 2232 , and the through hole 2232 passes through both sides of the second bending portion 223 in the thickness direction.

[0246] The through hole 2232 may have various shapes. For example, the through hole 2232 may be a circular hole, a bar hole, an elliptical hole, a polygonal hole, etc.

[0247] The number of the through hole 2232 can be one or more. In the embodiment where the number of the through holes 2232 is more than one, the plurality of through holes 2232 are arranged at intervals in the second bending portion 223 .

[0248] The second bend portion 223 is provided with a through hole 2232. The through hole 2232 is formed in a simple and convenient manner, thereby reducing the strength of the second bend portion 223 and making it easier to bend, thereby forming the insulating body 221, the restraining portion 222, and the second bend portion 223. The provision of the through hole 2232 also helps reduce the weight of the battery cell 20.

[0249] In some embodiments, a groove (not shown) is provided on at least one surface of the second bending portion 223 along the thickness direction of the second bending portion 223 .

[0250] The groove is recessed from the surface of the second bend portion 223 in the thickness direction, and the depth of the recess is less than the thickness of the second bend portion 223. Along the thickness direction of the second bend portion 223, the groove can be provided on one side of the second bend portion 223, or on both opposite sides of the second bend portion 223.

[0251] The number of grooves can be one or more.

[0252] A groove is provided on at least one surface of the second bending portion 223 along the thickness direction of the second bending portion 223 , so that the method of reducing the strength of the second bending portion 223 is simple and convenient.

[0253] The second bending portion 223 may be provided with only a through hole or only a groove, or may be provided with both a through hole 2232 and a groove.

[0254] The number of second bends 223 can be one, i.e., the insulating body 221 and the extension section 2222 are connected by a single second bend 223, thereby simplifying the structure of the battery cell 20. In the embodiment where there is only one second bend 223, the size of the second bend 223 along the third direction Z can be smaller than that of the insulating body 221, or the size of the second bend 223 can be the same as that of the insulating body 221.

[0255] As shown in FIG10 , in some embodiments, the battery cell 20 includes a plurality of second bending portions 223 , which are spaced apart along the third direction Z. The first direction X, the second direction Y, and the third direction Z are not coplanar and intersect with each other.

[0256] Each second bending portion 223 connects the insulating body 221 and the extending section 2222 , and the extending section 2222 and the insulating body 221 are connected via the plurality of second bending portions 223 .

[0257] The battery cell 20 includes a plurality of second bending portions 223 spaced apart in the third direction Z, so that the connection stability between the insulating body 221 and the extension section 2222 is improved.

[0258] The second bending portion 223 can be connected to a section of the extension section 2222 of the binding portion 222 away from the abutting section 2221, or can be connected to the middle area of ​​the extension section 2222. Of course, the second bending section can also be connected to the abutting section 2221 of the binding portion 222.

[0259] The insulating body 221 and the binding portion 222 are connected via the second bending portion 223 , which facilitates manufacturing and molding.

[0260] In some embodiments, the binding portion 222 and the insulating body 221 are integrally formed.

[0261] The binding portion 222 and the insulating body 221 are integrally formed, which means that the binding portion 222 and the insulating body 221 are formed in an integral manner. The integral forming method may be injection molding, stamping, bending, etc.

[0262] In an embodiment where the battery cell 20 further includes a second bend 223, the insulating body 221, the restraining portion 222, and the second bend 223 are integrally formed, for example, by bending a single sheet of material. For example, as shown in FIG7 , before the restraining portion 222, the insulating body 221, and the second bend enter the housing 21, the second bend 223 is a straight-line, plate-like structure, with the insulating body 221 and the restraining portion 222 respectively connected to opposite ends of the second bend 223 along the first direction X. By bending the restraining portion 222 relative to the insulating body 221 at the second bend 223 about an axis parallel to the third direction Z, the second bend 223 assumes an arc-shaped bent state, forming the state shown in FIG8 . After the insulating body enters the housing 21, the restraining portion 222 can be positioned between the first wall 211 and the first tab 233 and abut against the surface of the first tab 233 facing the first wall 211.

[0263] The binding portion 222 and the insulating body 221 are integrally formed, which facilitates the binding portion and the insulating body to form an integrated structure, and is conducive to the overall structure formed by the binding portion and the insulating body having better strength.

[0264] In other embodiments, the restraining portion 222 and the insulating body 221 may be provided as separate parts and then connected as one. In embodiments where the battery cell 20 includes the restraining portion 222 and the insulating body 221 but does not include the second bending portion, the restraining portion 222 and the insulating body 221 may be detachably connected, such as by bolts, snaps, etc. The restraining portion 222 and the insulating body 221 may be fixedly connected, such as by welding, bonding, etc. In embodiments where the battery cell 20 also includes the second bending portion 223, the insulating body 221, the restraining portion 222, and the second bending portion 223 may be provided as separate parts and then connected as one, and the second bending portion 223 and the insulating body 221 may be detachably connected, such as by bolts, snaps, etc. The second bending portion 223 and the insulating body 221 may be fixedly connected, such as by welding, bonding, etc. The second bending portion 223 and the restraining portion 222 may be detachably connected, such as by bolts, snaps, etc. The second bending portion 223 and the binding portion 222 may be fixedly connected, such as by welding, bonding, etc.

[0265] As shown in FIG. 10 to FIG. 14 , in some embodiments, the battery cell 20 includes a locking structure 224 for locking the restraining portion 222 and the insulating body 221 to restrict the restraining portion 222 from flipping relative to the insulating body 221 toward the first wall portion 211 .

[0266] During the charging and discharging process of the battery cell 20, gas generation inside the battery cell 20 may cause the air pressure between the pole pieces of the electrode assembly 23 to increase, thereby generating a driving force on the binding portion 222 toward the first wall portion 211, causing the binding portion 222 to flip around the connection position between the binding portion 222 and the insulating body 221, thereby weakening the binding effect of the binding portion 222 on the first pole ear 233 or causing the binding portion 222 to lose its binding effect on the first pole ear 233.

[0267] The insulating body 221 and the restraining portion 222 can be locked together using a single locking structure 224, simplifying the structure of the battery cell 20. The insulating body 221 and the restraining portion 222 can also be locked together using multiple locking structures 224 to further enhance locking stability. In embodiments where the insulating body 221 and the restraining portion 222 are locked together using multiple locking structures 224, the multiple locking structures 224 can be spaced apart along the third direction Z.

[0268] The locking structure 224 can be disposed at any position between the restraining portion 222 and the insulating body 221. In this embodiment, when viewed along the second direction Y, the projection of the abutting segment 2221 does not overlap with the projection of the locking structure 224. When viewed along the second direction Y, the projection of the first tab 233 does not overlap with the projection of the locking structure 224. When viewed along the second direction Y, the projection of the first tab 233 is located between the projections of two adjacent locking structures 224. When viewed along the second direction Y, the projection of the abutting segment 2221 is located between the projections of two adjacent locking structures 224. When viewed along the first direction X, the projection of the first tab 233 does not overlap with the projection of the locking structure 224, and the projection of the abutting segment 2221 does not overlap with the projection of the locking structure 224.

[0269] The binding portion 222 and the insulating body 221 are locked by the locking structure 224 to limit the binding portion 222 from flipping relative to the insulating body 221 in the direction close to the first wall portion 211, so as to reduce the risk of the binding portion 222 detaching from the first pole ear 233, so that the binding portion 222 can stably bind the first pole ear 233, thereby reducing the gap between the pole pieces of the electrode assembly 23 closer to the first wall portion 211, which is beneficial to improving the cycle performance of the battery cell 20.

[0270] In some embodiments, the locking structure 224 includes a first locking portion 2241 and a second locking portion 2242 . The first locking portion 2241 is configured to engage with the second locking portion 2242 to lock the insulating body 221 and the restraining portion 222 .

[0271] As shown in FIG. 11 to FIG. 14 , in some embodiments, the first locking portion 2241 is provided with a locking hole 22411 , and the second locking portion 2242 is engaged in the locking hole 22411 .

[0272] The locking hole 22411 is provided at one end of the first locking portion 2241 along the first direction X. The axial direction of the locking hole 22411 is parallel to the first direction X. The end of the locking hole 22411 closest to the first wall portion 211 serves as an entrance to the locking hole 22411 for inserting the second locking portion 2242. The second locking portion 2242 is an elastic member that can deform radially relative to the locking hole 22411. As shown in FIG12 , when the restraining portion 222 is not flipped relative to the insulating body 221 about an axis parallel to the third direction Z, the axial direction of the locking hole 22411 is parallel to the first direction X, and the extension direction of the second locking portion 2242 is parallel to the second direction Y. As shown in FIG14 , after the restraining portion 222 is flipped relative to the insulating body 221 about an axis parallel to the third direction Z, and before the second locking portion 2242 is engaged with the locking hole 22411, the second locking portion 2242 is deformed radially along the locking hole 22411. The deformed second locking portion 2242 is inserted into the locking hole 22411. The force driving the deformation of the second locking portion 2242 is then removed, and the second locking portion 2242 returns to its original shape, thereby engaging with the first locking portion 2241. The axis of the locking hole 22411 is parallel to the first direction X, and the extension direction of the second locking portion 2242 is parallel to the first direction X.

[0273] The locking hole 22411 can be a hole of uniform diameter or a stepped hole. Figures 11 to 14 show that the locking hole 22411 is a hole of uniform diameter.

[0274] The first locking portion 2241 is provided with a locking hole 22411 , and the second locking portion 2242 is engaged in the locking hole 22411 , which not only facilitates locking of the insulating body 221 and the restraining portion 222 , but also simplifies the structure of the locking structure 224 .

[0275] As shown in Figures 15 and 16, in some embodiments, the second locking portion 2242 includes a first elastic portion 22421 and a second elastic portion 22422 arranged relatively spaced apart, and the second locking portion 2242 is configured to be able to be inserted into the locking hole 22411 when the first elastic portion 22421 and the second elastic portion 22422 are close to each other.

[0276] The arrangement direction of the first elastic portion 22421 and the second elastic portion 22422 is parallel to the radial direction of the locking hole 22411. One end of the first elastic portion 22421 is connected to the restraining portion 222, and one end of the second elastic portion 22422 is connected to the restraining portion 222. The first elastic portion 22421 and the second elastic portion 22422 are close to each other, so that the first elastic portion 22421 and the second elastic portion 22422 can be deformed in a direction close to each other, thereby facilitating the insertion of the second locking portion 2242 into the locking hole 22411. The connection position of the first elastic portion 22421 and the restraining portion 222, and the connection position of the second elastic portion 22422 and the restraining portion 222 of the second locking portion 2242 can be separated from each other.

[0277] As shown in Figures 15 and 16, the first elastic portion 22421 includes a first limiting portion 224211 and a first body 224212. One end of the first body 224212 is connected to the restraining portion 222. The first limiting portion 224211 is provided at the end of the first body 224212 away from the restraining portion 222. The first limiting portion 224211 protrudes from the outer surface of the first body 224212 facing away from the second elastic portion 22422. The second elastic portion 22422 includes a second limiting portion 224221 and a second body 224222. One end of the second body 224222 is connected to the restraining portion 222. The second limiting portion 224221 is provided at the end of the second body 224222 away from the restraining portion 222. The second limiting portion 224221 protrudes from the outer surface of the second body 224222 facing away from the first elastic portion 22421. The first limiting portion 224211 and the second limiting portion 224221 are used to abut against the first locking portion 2241 after the second locking portion 2242 is inserted into the locking hole 22411 , thereby achieving the engagement between the first locking portion 2241 and the second locking portion 2242 .

[0278] Continuing with reference to Figures 15 and 16, in some embodiments, the outer circumference of the first limiting portion 224211 includes a first guide surface 224213 extending to an end of the first limiting portion 224211 away from the restraining portion 222. The outer circumference of the second limiting portion 224221 includes a second guide surface 224223 extending to an end of the second limiting portion 224221 away from the restraining portion 222. The first guide surface 224213 and the second guide surface 224223 can engage with the wall of the locking hole 22411 when the second locking portion 2242 is inserted into the locking hole 22411. The first guide surface 224213 and the second guide surface 224223 cooperate with the wall of the locking hole 22411 to drive the first elastic portion 22421 and the second elastic portion 22422 to deform toward each other, thereby inserting the second locking portion 22411 into the locking hole 22411. The first guide surface 224213 may be an inclined surface, a conical surface, a pyramidal surface, etc., and the second guide surface 224223 may be an inclined surface, a conical surface, a pyramidal surface, etc. FIG15 shows a case where both the first guide surface 224213 and the second guide surface 224223 are conical surfaces, and FIG16 shows a case where both the first guide surface 224213 and the second guide surface 224223 are inclined surfaces.

[0279] In some embodiments, as shown in Figures 17 and 18 , the wall surface of the locking hole 22411 includes a third guide surface 22412, and the third guide slope extends to the entrance of the locking hole 22411. The third guide surface 22412 is configured to cooperate with the first guide surface 224213 and the second guide surface 224223. The third guide surface 22412, the first guide surface 224213, and the second guide surface 224223 cooperate to guide the second locking portion 2242 into the locking hole 22411. The third guide surface 22412 may be an inclined surface, a conical surface, a pyramidal surface, etc. Of course, as shown in Figures 12 and 14 , the wall surface of the locking hole 22411 may also not include the third guide surface 22412.

[0280] In other embodiments, as shown in Figures 19 and 20, the locking hole 22411 can be a two-stage stepped hole. The locking hole 22411 includes a first hole segment 22413 and a second hole segment 22414 connected to each other. The diameter of the first hole segment 22413 is larger than the diameter of the second hole segment 22414. Along the first direction X, the first hole segment 22413 is connected to the end of the second hole segment 22414 away from the first wall portion 211. A stepped surface 22415 is formed between the first hole segment 22413 and the second hole segment 22414.

[0281] When the first locking portion 2241 and the second locking portion 2242 are engaged, an external force is applied to the first elastic portion 22421 and the second elastic portion 22422 to drive the first elastic portion 22421 and the second elastic portion 22422 to deform, so that the end of the first elastic portion 22421 provided with the first limiting portion 224211 and the end of the second elastic portion 22422 provided with the second limiting portion 224221 are close to each other, and the deformed first elastic portion 22421 and the second elastic portion 22422 are inserted into the locking hole. 22411, and then the external force applied to the first elastic part 22421 and the second elastic part 22422 is removed, the first elastic part 22421 and the second elastic part 22422 return to their original state, and the surface of the first limiting part 224211 of the first elastic part 22421 facing the restraining part 222 and the surface of the second limiting part 224221 of the second elastic part 22422 facing the restraining part 222 both abut against the step surface 22415, thereby realizing the engagement between the first locking part 2241 and the second locking part 2242.

[0282] In the embodiment where the locking hole 22411 is a two-stage stepped hole, the first conical surface and the second conical surface can cooperate with the hole wall of the second hole section 22414 of the locking hole 22411 when the second locking portion 2242 is inserted into the locking hole 22411. The first conical surface and the second conical surface cooperate with the hole wall of the second hole section 22414 to drive the first elastic portion 22421 and the second elastic portion 22422 to deform in a direction close to each other, thereby inserting into the second hole section 22414. When the first limit After the first and second limiting portions 224211 and 224221 are separated from the wall of the second hole section 22414 and moved into the first hole section 22413, the first and second elastic portions 22421 and 22422 are reset, and the surface of the first limiting portion 224211 facing the restraining portion 222 and the surface of the second limiting portion 224221 facing the restraining portion 222 both abut against the step surface 22415, thereby achieving the engagement between the first locking portion 2241 and the second locking portion 2242. This structure allows the first and second elastic portions 22421 and 22422 to be deformed without applying external force to the first and second elastic portions 22421 and 22422.

[0283] The second locking portion 2242 includes a first elastic portion 22421 and a second elastic portion 22422 that are arranged relatively spaced apart, so as to facilitate the engagement between the first locking portion 2241 and the second locking portion 2242 .

[0284] In some embodiments, the first locking portion 2241 is disposed on the insulating body 221 , and the second locking portion 2242 is disposed on the restraining portion 222 ; or the first locking portion 2241 is disposed on the restraining portion 222 , and the second locking portion 2242 is disposed on the insulating body 221 .

[0285] For example, as shown in FIG10 , the first locking portion 2241 is disposed on a side of the insulating body 221 facing the main body portion and protrudes from the surface of the insulating body 221 facing the main body portion. The first locking portion 2241 and the insulating body 221 may be integrally formed. The first locking portion 2241 and the insulating body 221 may also be provided as separate parts and then connected to form a whole, such as by welding, bonding, bolting, etc.

[0286] The second locking portion 2242 is provided on the extension section 2222 of the restraining portion 222. The second locking portion 2242 and the restraining portion 222 may be integrally formed. The second locking portion 2242 and the restraining portion 222 may also be provided as separate parts and then connected to form a whole, for example, by welding, gluing, bolting, etc.

[0287] The first locking portion 2241 on the insulating body 221 and the second locking portion 2242 on the restraining portion 222 are engaged with each other, thereby facilitating locking of the insulating body 221 and the restraining portion 222 .

[0288] By setting the first locking part 2241 on the insulating body 221 and the second locking part 2242 on the binding part 222, or setting the first locking part 2241 on the binding part 222 and the second locking part 2242 on the insulating body 221, that is, the first locking part 2241 and the second locking part 2242 are respectively set on the insulating body 221 and the binding part 222, the arrangement of the first locking part 2241 and the second locking part 2242 and the snap-fitting of the first locking part 2241 and the second locking part 2242 are facilitated.

[0289] In some embodiments, the first locking portion 2241 is disposed on the insulating body 221 and protrudes from the surface of the insulating body 221 facing the main body 231 ; the second locking portion 2242 is disposed on the binding portion 222 and protrudes from the surface of the binding portion 222 facing the first tab 233 .

[0290] The first locking portion 2241 is arranged on the insulating body 221 and protrudes from the surface of the insulating body 221 facing the main body 231. The first locking portion 2241 can be closer to the main body 231, which can limit the range of movement of the electrode assembly 23 inside the shell 21 and alleviate the problem of the electrode assembly 23 moving inside the shell 21.

[0291] The first locking portion 2241 can be one or more. In embodiments where there are multiple first locking portions 2241, the multiple first locking portions 2241 are spaced apart on the insulating body 221. As shown in Figures 5 and 10, the battery cell 20 includes two first locking portions 2241, which are spaced apart along the third direction Z.

[0292] The second locking portion 2242 is provided on the tie portion 222 and protrudes from the surface of the tie portion 222 facing the first tab 233, facilitating the engagement of the second locking portion 2242 with the first locking portion 2241. In an embodiment where the first locking portion 2241 is provided with a locking hole 22411, the second locking portion 2242 protrudes from the surface of the tie portion 222 facing the first tab 233, allowing the second locking portion 2242 to be inserted into the locking hole 22411, thereby achieving engagement between the first locking portion 2241 and the second locking portion 2242.

[0293] The first locking portion 2241 is provided on the insulating body 221 and protrudes from the surface of the insulating body 221 facing the main body 231; the second locking portion 2242 is provided on the binding portion 222 and protrudes from the surface of the binding portion 222 facing the first pole ear 233, so as to facilitate the cooperation between the first locking portion 2241 and the second locking portion 2242.

[0294] In some embodiments, the housing 21 includes a shell 214 and an end cover 215 . The shell 214 has an opening 213 . The end cover 215 covers the opening 213 . The second wall portion 212 serves as the end cover 215 .

[0295] The housing 214 may be provided with an opening 213 , and the corresponding outer shell 21 includes an end cover 215 , which closes the opening 213 . The second wall portion 212 is the end cover 215 .

[0296] The housing 214 may have two openings 213 , which may be arranged opposite each other along the second direction Y. The outer shell 21 may include two end caps 215 , which may be arranged opposite each other along the second direction Y. The openings 213 and the end caps 215 are provided in a one-to-one correspondence, with the end caps 215 covering the corresponding openings 213 . In embodiments where the outer shell 21 includes two end caps 215 and the main body 231 of the electrode assembly 23 is provided with tabs 232 at both ends along the second direction Y, both end caps 215 may be the second wall portion 212 .

[0297] The second wall portion 212 is the end cover 215 , and the first wall portion 211 is the wall portion of the shell 214 , which facilitates the arrangement of the electrode assembly 23 and the first wall portion 211 , thereby facilitating the assembly of the battery cell 20 .

[0298] Continuing with reference to FIG. 4 and FIG. 6 , in some embodiments, the surface of the first tab 233 facing the first wall portion 211 includes a concave surface 2334 , and the restraining portion 222 abuts against the concave surface 2334 .

[0299] The concave surface 2334 is recessed along the direction from the first wall portion 211 toward the electrode assembly 23. The concave surface 2334 forms a recessed area, and the restraining portion 222 abuts against the concave surface 2334 in the recessed area formed in the concave surface 2334. In an embodiment where the abutting section 2221 bends toward the first electrode tab 233, and the end of the abutting section 2221 away from the extension section 2222 forms an abutting end 22211 that abuts against the first electrode tab root 2331, the abutting end 22211 bends into the recessed area to abut against the concave surface 2334. The concave surface 2334 may be located at the first electrode tab root 2331 of the first electrode tab 233.

[0300] The surface of the first electrode tab 233 facing the first wall portion 211 includes a concave surface 2334 , and the binding portion 222 abuts against the concave surface 2334 , so that the binding portion 222 and the first electrode tab 233 abut against each other with better stability.

[0301] As shown in Figure 4, in some embodiments, the shell 21 includes two first wall portions 211 arranged opposite to each other; the battery cell 20 includes a plurality of electrode assemblies 23, and the plurality of electrode assemblies 23 are arranged between the two first wall portions 211 along the first direction X, and the pole ears 232 of the electrode assemblies 23 at both ends along the first direction X are all first pole ears 233; the plurality of electrode assemblies 23 are provided with restraining portions 222 on both sides along the first direction X, and the restraining portions 222 on both sides of the plurality of electrode assemblies 23 respectively abut against the first pole ears 233 of the electrode assemblies 23 at both ends along the first direction X.

[0302] Taking all the electrode assemblies 23 as a whole, both sides of the plurality of electrode assemblies 23 along the first direction X are provided with a restraining portion 222 .

[0303] In the embodiment where the battery cell 20 includes an insulating body 221 , the insulating body 221 is provided with binding portions 222 on both sides along the first direction X. Along the first direction X, the binding portions 222 provided on both sides of the insulating body 221 may have the same or different structures.

[0304] In embodiments where the battery cell 20 includes one electrode assembly 23, the tab 232 of the electrode assembly 23 is a first tab 233. Along the first direction X, the surface of the first tab 233 closest to the first wall portion 211 abuts against the restraining portion 222. The insulating body 221 may be provided with the restraining portion 222 only on the side corresponding to the surface of the first tab 233 closest to the first wall portion 211. Of course, in embodiments where the battery cell 20 includes one electrode assembly 23, restraining portions 222 may also be provided on opposite sides of the insulating body 221 along the first direction X. The restraining portions 222 on both sides of the insulating body 221 respectively abut against two opposite surfaces of the first tab 233 of the electrode assembly 23 along the first direction X.

[0305] In an embodiment where the battery cell 20 includes multiple electrode assemblies 23, the housing 21 includes two opposing first walls 211 along a first direction X. The multiple electrode assemblies 23 are arranged between the two first walls 211 along the first direction X. The tabs 232 of the electrode assemblies 23 at both ends of the housing 221 along the first direction X are both first tabs 233. The insulating body 221 is provided with restraining portions 222 on both sides of the insulating body 221 along the first direction X. The restraining portions 222 on either side of the insulating body 221 abut against the surfaces of the first tabs 233 of the electrode assemblies 23 at both ends of the housing 221 along the first direction X that face the corresponding first walls 211. As shown in FIG. 4 , the battery cell 20 includes two electrode assemblies 23, both of which have first tabs 233. The insulating body 221 is provided with restraining portions 222 on both sides of the insulating body 221 along the first direction X. The restraining portions 222 on either side of the insulating body 221 abut against the surfaces of the first tabs 233 of the electrode assemblies 23 at both ends of the housing 221 that face the corresponding first walls 211.

[0306] The insulating body 221 is provided with a restraining portion 222 on both sides along the first direction X. The restraining portions 222 on both sides of the insulating body 221 respectively abut against the first pole ears 233 of the electrode assemblies 23 located at both ends along the first direction X, and can restrain the first pole ears 233 of the two electrode assemblies 23 located at the end, thereby reducing the gap between the layers of the first pole ears 233 of the two electrode assemblies 23 at the end, thereby reducing the gap between the pole piece main body areas connected to the first pole ears 233, so that the gap between the pole pieces on the side closest to the first wall portion 211 of the two electrode assemblies 23 at the end is smaller, which is beneficial to improving the cycle performance of the battery cell 20.

[0307] The multiple electrode assemblies 23 are regarded as a whole, and the whole is provided with a restraining portion 222 on both sides along the first direction X. The restraining portions 222 on both sides of the multiple electrode assemblies 23 respectively abut against the first pole ears 233 of the electrode assemblies 23 located at both ends along the first direction X, and can restrain the first pole ears 233 of the two electrode assemblies 23 located at the end, thereby reducing the gap between the layers of the first pole ears 233 of the two electrode assemblies 23 at the end, thereby reducing the gap between the pole piece main body areas connected to the first pole ears 233, so that the gap between the pole pieces 23a on the side closest to the first wall portion 211 of the two electrode assemblies 23 located at the end is smaller, which is beneficial to improving the cycle performance of the battery cell 20.

[0308] In some embodiments, the average charge rate of the battery cells 20 is K, satisfying K≥1.

[0309] For example, K is 1, 2, 3, 4, 5, or 6.

[0310] The charge rate is a measure of charging speed, and refers to the current value required to charge the battery 100 to its rated capacity within a specified time.

[0311] For example, taking 4C fast charging as an example, the battery cell 20 can be fast charged and tested as follows:

[0312] (i) leaving the battery cell 20 at rest for 10 minutes, and then charging the battery cell 20 to 97% SOC (State of Charge) with an equivalent current of 4C;

[0313] (ii) leaving the battery cell 20 at rest for 30 minutes, and then discharging the battery cell 20 at a constant current of 1C to 3% SOC;

[0314] (iii) repeating steps (i) and (ii) 50 times;

[0315] (iv) charging the battery cell 20 to 97% SOC with an equivalent 4C current;

[0316] (v) Disassemble the battery cell 20, and take the lithium-ion battery cell as an example to observe the lithium deposition on the surface of the negative electrode. For example, flatten the negative electrode and measure the total area S1 of the negative electrode active material layer on one side of the negative electrode; measure the maximum dimension a of each lithium deposition point on the negative electrode active material layer (there is no lithium deposition around the lithium deposition point) along the length direction of the negative electrode, and measure the maximum dimension b of each lithium deposition point along the width direction of the negative electrode. Take a / 2 as the median value of the lithium deposition point in the length direction, and b / 2 as the median value of the lithium deposition point in the width direction. The area of ​​the lithium deposition point is a×b / 4. The sum of the areas of all lithium deposition points is S2. If S2 / S1≤5%, it is considered that the battery cell meets the 4C fast charging requirements.

[0317] K≥1, which can achieve fast charging of battery cells.

[0318] The embodiment of the present application further provides a battery 100 , which includes the battery cell 20 provided in the above embodiment.

[0319] The above embodiment provides good cycle performance, and the battery 100 including the battery cell 20 has good cycle performance.

[0320] An embodiment of the present application further provides an electrical device, which includes the battery cell 20 provided in the above embodiment.

[0321] An embodiment of the present application provides a battery cell 20, which includes a housing 21, a restraining portion 222, an insulating body 221, a second bend portion 223, and two electrode assemblies 23. The housing 21 includes a shell 214 and an end cap 215. The shell 214 has two first walls 211 disposed opposite each other along a first direction X. One end of the shell 214 has an opening 213 along a second direction Y, and the end cap 215 seals the opening 213. The two electrode assemblies 23 are disposed between the two first walls 211 along the first direction X. Each electrode assembly 23 includes a main body 231 and a tab 232, which is connected to one end of the main body 231 along the second direction Y, proximate to the end cap 215. Each electrode assembly 23 includes two tabs 232 of opposite polarity. The two tabs 232 of each electrode assembly 23 are spaced apart along a third direction Z, with the first direction X, the second direction Y, and the third direction Z being perpendicular to each other. The battery cell 20 includes an insulating body 221, a second bent portion 223 and two binding portions 222. The insulating body 221, the second bent portion 223 and the two binding portions 222 are integrally formed. The insulating body 221 is arranged between the pole lug 232 and the end cover 215 to insulate and separate the pole lug 232 and the end cover 215. Along the first direction X, binding portions 222 are provided on both sides of the insulating body 221. The binding portion 222 includes an extension section 2222 and a rest section 2221, one end of the extension section 2222 is connected to the rest section 2221, the rest section 2221 is bent toward the first pole lug 233, and the end of the rest section 2221 away from the extension end forms a rest end 22211, and the rest end 22211 rests against the concave surface 2334 of the first pole lug root 2331 of the first pole lug 233 facing the first wall portion 211. The tie portion 222 includes two abutment sections 2221 spaced apart from the extension section 2222 along the third direction Z. The extension section 2222 of each tie portion 222 is connected to the insulating body 221 via two second bent sections 223. The thickness of both the insulating body 221 and the extension section 2222 is greater than the thickness of the second bent sections 223. Each second bent section 223 is provided with a plurality of spaced-apart through-holes 2232.

[0322] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, comprising: a housing having a first wall portion; at least one electrode assembly housed in the housing, the electrode assembly comprising electrode sheets stacked along a first direction, the electrode sheets and the first wall portion stacked along the first direction, the electrode assembly comprising a main body and a tab, the tab being provided at least at one end of the main body along a second direction, the first direction and the second direction intersecting; a restraining portion, disposed in the housing; Among them, along the first direction, the electrode tab of the electrode assembly closest to the first wall portion is the first tab, and the restraining portion is at least partially located between the first tab and the first wall portion and abuts against the surface of the first tab facing the first wall portion.

2. The battery cell according to claim 1, wherein: The electrode assembly closest to the first wall portion along the first direction has a center plane perpendicular to the first direction, and the first electrode tab is at least partially disposed on a side of the center plane close to the first wall portion.

3. The battery cell according to claim 1, wherein: Along the first direction, there is a distance between the first wall portion and the main body portion of the electrode assembly closest to the first wall portion.

4. The battery cell according to claim 1, wherein: The first electrode tab includes a plurality of electrode tabs stacked along the first direction, and a connection position between the main body and the electrode tab closest to the first wall portion among the plurality of electrode tabs of the first electrode tab is a first position; The restraining portion has an abutting end abutting against the first tab. Along the first direction, a distance between an end of the abutting end away from the first wall and the first wall is greater than a distance between the first position and the first wall.

5. The battery cell according to claim 4, wherein: The surface of the abutting end abutting against the first electrode tab is an arc surface. The battery cell according to claim 1 , wherein: The housing has a second wall portion, the second wall portion and the tab are arranged along the second direction, the battery cell includes an electrode terminal, and the electrode terminal is provided on the second wall portion; The first tab includes a first tab root, a first bent portion, and a first connecting portion, wherein the first tab root is connected to the main body, the first bent portion connects the first tab root and the first connecting portion, and the first connecting portion is electrically connected to the electrode terminal; The restraining portion abuts against a surface of the first tab root portion facing the first wall portion.

7. The battery cell according to claim 6, wherein: The battery cell further includes an insulating layer, which is at least partially disposed on a surface of the first electrode tab root.

8. The battery cell according to claim 6, wherein: The restraining portion includes a resting section and an extension section, wherein the extension section is at least partially located between the first pole lug and the first wall portion, and along the direction of the pole lug pointing to the main body portion, the resting section protrudes from one end of the extension section, and rests against the root of the first pole lug.

9. The battery cell according to claim 8, wherein: The abutting section protrudes from the extending section in the first direction away from the first wall portion.

10. The battery cell according to claim 7, wherein: The electrode assembly closest to the first wall portion along the first direction has a center plane perpendicular to the first direction, and the first bending portion is located on a side of the center plane facing the first wall portion.

11. The battery cell according to claim 1, wherein The restraining portion includes an extending section and a supporting section, and the supporting section is bent from the extending section toward the first tab.

12. The battery cell according to claim 11, wherein: One end of the abutting section away from the extending section forms an abutting end, which abuts against the first tab. The abutting section has a first surface facing the first tab, which extends to the abutting end and is an arc surface.

13. The battery cell according to claim 12, wherein: The extension section has a second surface facing the first tab, the first surface and the second surface are connected, and the distance between the second surface and the first wall portion in the first direction gradually increases along the direction from the tab to the main body.

14. The battery cell according to claim 12, wherein: The electrode assembly closest to the first wall portion includes a plurality of first electrode tabs, and the plurality of first electrode tabs are arranged along a third direction; The extension section is provided with a plurality of abutting sections, and the plurality of abutting sections are arranged at intervals along the third direction. One first tab corresponds to at least one abutting section. The first direction, the second direction and the third direction are not coplanar and intersect with each other.

15. The battery cell according to any one of claims 1 to 14, wherein: The housing has a second wall portion, the second wall portion is adjacent to and connected to the first wall portion, and the second wall portion and the tab are arranged along the second direction; The battery cell further includes an insulating body, which is disposed on a side of the tab facing the second wall portion to insulate and isolate the second wall portion from the tab, and the binding portion is connected to the insulating body.

16. The battery cell according to claim 15, wherein: The restraining portion includes an extending section and a resting section, wherein the extending section is at least partially located between the first electrode tab and the first wall portion, and the resting section protrudes from one end of the extending section and rests against the first electrode tab; The battery cell further includes a second bending portion connecting the insulating body and the extending section.

17. The battery cell according to claim 16, wherein: The thickness of the insulating body and the thickness of the extending section are both greater than the thickness of the second bending portion.

18. The battery cell according to claim 16 or 17, wherein: The second bending portion is provided with a through hole, and the through hole passes through both sides of the second bending portion in the thickness direction; and / or the second bending portion is provided with a groove on at least one surface along the thickness direction of the second bending portion.

19. The battery cell according to claim 16, wherein: The battery cell includes a plurality of second bending portions, and the plurality of second bending portions are arranged at intervals along a third direction. The first direction, the second direction, and the third direction are not coplanar and intersect with each other.

20. The battery cell according to claim 15, wherein The restraining portion and the insulating body are integrally formed.

21. The battery cell according to claim 15, wherein The battery cell further includes a locking structure, which is used to lock the binding portion and the insulating body to restrict the binding portion from flipping relative to the insulating body in a direction close to the first wall portion.

22. The battery cell according to claim 21, wherein The locking structure includes a first locking portion and a second locking portion, wherein the first locking portion is configured to engage with the second locking portion to lock the insulating body and the restraining portion.

23. The battery cell according to claim 22, wherein: The first locking portion is provided with a locking hole, and the second locking portion is engaged in the locking hole.

24. The battery cell according to claim 23, wherein: The second locking portion includes a first elastic portion and a second elastic portion that are spaced apart from each other, and the second locking portion is configured to be insertable into the locking hole when the first elastic portion and the second elastic portion are close to each other.

25. The battery cell according to any one of claims 22 to 24, wherein: The first locking portion is provided on the insulating body, and the second locking portion is provided on the restraining portion; or the first locking portion is provided on the restraining portion, and the second locking portion is provided on the insulating body.

26. The battery cell according to claim 22, wherein The first locking portion is provided on the insulating body and protrudes from a surface of the insulating body facing the main body; the second locking portion is provided on the binding portion and protrudes from a surface of the binding portion facing the first tab.

27. The battery cell according to claim 21, wherein The housing comprises: a housing having an opening; An end cover seals the opening, and the second wall portion serves as the end cover.

28. The battery cell according to claim 1, wherein A surface of the first tab facing the first wall portion includes a concave surface, and the restraining portion abuts against the concave surface.

29. The battery cell according to claim 1, wherein The housing includes two first wall portions arranged opposite to each other; The battery cell includes a plurality of electrode assemblies, which are arranged between two first walls along the first direction, and the tabs of the electrode assemblies at both ends along the first direction are both the first tabs; The restraining parts are provided on both sides of the plurality of electrode assemblies along the first direction, and the restraining parts on both sides of the plurality of electrode assemblies respectively abut against the first tabs of the electrode assemblies located at both ends along the first direction.

30. A battery comprising the battery cell according to any one of claims 1 to 29.

31. An electrical device comprising the battery cell according to any one of claims 1 to 29.

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