Battery cells, batteries and electrical devices

Abstract

This application discloses a battery cell, a battery, and an electrical device. The battery cell includes an electrode assembly and a housing. The electrode assembly includes a main body and a first tab, the first tab extending from one end of the main body along a first direction. The housing has a receiving cavity, in which the electrode assembly is disposed. The housing has a first through hole and a second through hole, the portion of the receiving cavity located on one side of the first tab communicating with the first through hole, and the portion of the receiving cavity located on the side of the main body opposite to the first tab communicating with the second through hole, the first through hole being used for injecting electrolyte. Axially, neither the first tab nor the main body overlaps with the first through hole. This application can improve the cycle performance of the battery cell.

Description

Battery cells, batteries, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311458303.3, filed on November 03, 2023, entitled “Battery Cell, Battery, and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Battery cells are widely used in electronic devices such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0005] In the development of battery technology, how to improve the cycle performance of battery cells is a research direction in battery technology.

[0006] Summary of the Invention

[0007] The present application provides a battery cell, a battery, and an electrical device, which can improve the cycle performance of the battery cell.

[0008] In a first aspect, the present application provides a battery cell comprising an electrode assembly and a housing. The electrode assembly comprises a main body and a first tab, the first tab extending from one end of the main body along a first direction. The housing has a housing cavity, and the electrode assembly is disposed in the housing cavity. The housing is provided with a first through hole and a second through hole, wherein a portion of the housing cavity located on one side of the first tab is connected to the first through hole, and a portion of the housing cavity located on a side of the main body away from the first tab is connected to the second through hole, and the first through hole is used for injecting electrolyte. In the axial direction of the first through hole, neither the first tab nor the main body overlaps with the first through hole.

[0009] During the production process of the battery cell, the electrolyte can be injected into the accommodating cavity through the first through hole. During the injection of the electrolyte, the gas in the accommodating cavity can be discharged through the second through hole, so that the electrolyte can be injected into the interior of the battery cell under normal pressure, and the resistance to the electrolyte injection is reduced, eliminating the conventional vacuum process, thereby improving efficiency. The first through hole and the second through hole are respectively connected to the spaces located on both sides of the main body along the first direction, so that the electrolyte can fully infiltrate the main body during the flow process, improve the electrolyte infiltration effect on the electrode assembly, and improve the cycle performance of the battery cell. When the electrolyte passes through the first through hole, the flow direction of the electrolyte is generally parallel to the axial direction of the first through hole; the embodiment of the present application can reduce the risk of the electrolyte directly impacting the main body and the first pole ear after flowing out of the first through hole, thereby reducing the impact force on the first pole ear and the main body, reducing the deformation of the first pole ear and the main body, and improving the reliability of the battery cell.

[0010] In some embodiments, the housing includes a first shell wall and a second shell wall disposed opposite each other along a second direction, with the main body located between the first shell wall and the second shell wall. The second direction is parallel to the thickness direction of the battery cell and perpendicular to the first direction. The first shell wall is flat, and the first through hole is disposed in the first shell wall. The first shell wall is located on one side of the electrode assembly along the thickness direction, is relatively flat, and has a large area, facilitating the placement of the first through hole.

[0011] In some embodiments, the minimum aperture of the first through hole is D1, the dimension of the first shell wall along the third direction is W, the third direction is perpendicular to the first direction and the second direction; 0.02≤D1 / W≤0.2.

[0012] Limiting D1 / W to greater than or equal to 0.02 improves electrolyte injection efficiency and improves the consistency of electrolyte wetting of the electrode assembly. Limiting D1 / W to less than or equal to 0.2 reduces strength damage to the first shell wall at the first through-hole, lowering the risk of cracking the first shell wall when the battery cell is subjected to external impact, and improving reliability.

[0013] In some embodiments, 2 mm ≤ D1 ≤ 10 mm, so as to improve the injection efficiency of the electrolyte, reduce the strength loss of the first shell wall, and lower the requirements for the injection equipment.

[0014] In some embodiments, the battery cell further includes a first seal connected to the housing and configured to seal the first through hole to reduce the risk of the accommodating cavity communicating with an external space of the battery cell via the first through hole.

[0015] In some embodiments, the first sealing member includes a first protrusion and a connecting portion arranged around the first protrusion, the connecting portion is located outside the shell and connected to the shell, and the first protrusion protrudes from a surface of the connecting portion away from the shell.

[0016] The first protrusion can act as a reinforcing rib to improve the strength of the shell at the first through hole, reduce the risk of cracking of the shell around the first through hole when the battery cell is subjected to external impact, and improve the reliability of the battery cell.

[0017] In some embodiments, in the axial direction of the first through-hole, the dimension H2 of the first protrusion protruding from the outer surface of the housing satisfies the following: 0.5 mm ≤ H2 ≤ 2 mm. Limiting H2 to greater than or equal to 0.5 mm increases the strength of the first seal, complements the strength of the housing, reduces the risk of housing cracking, and improves the reliability of the battery cell. Limiting H2 to less than or equal to 2 mm reduces the additional space occupied by the first seal in the axial direction of the first through-hole, minimizing the loss of energy density in the battery cell.

[0018] In some embodiments, the first seal has a first recess at a position corresponding to the first protrusion, the first recess being recessed relative to the surface of the connecting portion facing the housing. Providing the first recess can reduce the weight of the first seal and increase the energy density of the battery cell.

[0019] In some embodiments, the battery cell further includes a second sealant, a portion of the second sealant is inserted into the first through hole, and another portion of the second sealant is received in the first recess.

[0020] The second seal and the first seal function as a double seal, thereby improving sealing, reducing the risk of electrolyte leakage, and enhancing the reliability of the battery cell. The first recess not only allows the second seal to be positioned, but also limits and secures the second seal, reducing the risk of the second seal loosening when the battery cell is subjected to external impact, thereby improving the sealing and reliability of the battery cell.

[0021] In some embodiments, a housing recess is provided on the outer side of the housing. In a second direction, the first sealing member is located on a side of the housing away from the housing recess, and the second direction is perpendicular to the first direction.

[0022] By providing the housing recess, the volume of the battery cell can be reduced and the energy density can be increased. When multiple battery cells are arranged along the second direction, the housing recess of one battery cell can avoid the first sealing member of another battery cell, thereby improving space utilization and increasing the energy density of the battery.

[0023] In some embodiments, the first sealing member is welded to the housing to form a welded portion. Welding can increase the connection strength between the first sealing member and the housing and improve sealing performance.

[0024] In some embodiments, the outer shell is provided with a weak portion, and the minimum distance between the welding portion and the weak portion is greater than or equal to 1 mm, so as to reduce the impact of the heat-affected zone on the weak portion, reduce the thermal stress on the weak portion after welding, reduce the risk of rupture and failure of the weak portion, and improve the reliability of the battery cell.

[0025] In some embodiments, the welding portion is annular, the outer diameter of the welding portion is D2, the minimum aperture of the first through hole is D1, and 1.6≤D2 / D1≤2.5.

[0026] The ratio D2 / D1 is set to be greater than or equal to 1.6 to increase the strength of the weld, improve the structural strength of the battery cell around the first through-hole, and reduce the risk of cracking of the outer casing around the first through-hole. The ratio D2 / D1 is set to be less than or equal to 2.5 to limit the heat-affected zone generated by the weld and reduce the risk of failure of other structures of the battery cell due to thermal stress.

[0027] In some embodiments, the area of ​​the welding portion is S1, the area of ​​the minimum cross section of the first through hole perpendicular to its own axis is S2, and 1.5≤S1 / S2≤5.

[0028] S1 / S2 is limited to greater than or equal to 1.5 to increase the connection strength between the first seal and the housing, improve the structural strength of the battery cell around the first through-hole, and reduce the risk of the housing cracking around the first through-hole. In this embodiment of the application, S1 / S2 is limited to less than or equal to 5 to limit the heat-affected zone caused by welding and reduce the risk of failure of other structures of the battery cell due to thermal stress.

[0029] In some embodiments, the housing is provided with a second recess, the first through hole extends inwardly from a bottom surface of the second recess, and at least a portion of the first sealing member is configured to be accommodated in the second recess.

[0030] When assembling the first seal, the second recess can play a positioning role, thereby simplifying the assembly process of the first seal. By providing the second recess, the space additionally occupied by the first seal in the axial direction of the first through hole can also be reduced, thereby improving space utilization.

[0031] In some embodiments, the battery cell further includes a second sealant, a portion of which is inserted into the first through hole.

[0032] In some embodiments, the housing includes a first housing wall. The first housing wall includes a wall body and a first convex wall, at least a portion of the first convex wall protruding from a surface of the wall body facing the main body and located on one side of the main body along a first direction. The first convex wall includes a first wall body for defining a first through hole.

[0033] By providing the first convex wall protruding inward, the depth of the first through hole can be increased, the structural strength of the first shell wall around the first through hole can be improved, and the deformation of the first shell wall can be reduced.

[0034] In some embodiments, the dimension of the first wall along the second direction is H1, the minimum aperture of the first through hole is D1, and 0.2≤H1 / D1≤1. The second direction is parallel to the thickness direction of the wall body.

[0035] Limiting H1 / D1 to greater than or equal to 0.2 increases the structural strength and stability of the first wall and reduces the risk of deformation and cracking of the first wall. Limiting H1 / D1 to less than or equal to 1 reduces the space occupied by the first wall within the housing, lowering resistance to electrolyte flow within the housing and improving injection efficiency.

[0036] In some embodiments, the battery cell further includes a second sealing member, at least a portion of which is inserted into the first through hole and detachably connected to the first convex wall.

[0037] The second sealing member can be used to seal the first through-hole, improving the sealing performance of the battery cell. The second sealing member can be disassembled and assembled multiple times during the battery cell production process, facilitating multiple processing steps on the battery cell through the first through-hole. The first convex wall has a larger dimension in the second direction, and connecting the second sealing member to the first convex wall can improve the connection strength.

[0038] In some embodiments, the second sealing member is interference-fitted with the first through hole, which can effectively seal the first through hole and facilitate assembly and disassembly of the second sealing member.

[0039] In some embodiments, the second sealing member has a large end and a small end disposed axially opposite each other along the first through hole, with the small end located inward of the large end. The ratio of the diameter D4 of the small end to the minimum aperture D1 of the first through hole is 0.95-1.05, and the diameter of the large end is greater than the maximum aperture of the first through hole.

[0040] D4 / D1 is limited to 0.95-1.05 to facilitate the insertion of the second seal into the first through hole; the large end of the second seal has a larger size, which can reduce the risk of the second seal falling into the accommodating cavity through the first through hole, and effectively cover the first through hole to improve the sealing performance.

[0041] In some embodiments, an annular third recess is provided on the outer periphery of the second sealing member, and at least a portion of the first wall is accommodated in the third recess.

[0042] The first wall can be embedded in the third recess and form a riveted structure with the second sealing member, so that the first wall can limit the movement of the second sealing member in the second direction, thereby increasing the stability of the second sealing member and improving the sealing performance.

[0043] In some embodiments, the first convex wall further includes a second wall body, the second wall body being disposed around the first wall body and connecting the wall body and the first wall body, the second wall body protruding inwardly from the wall body and defining a second recessed portion, the second recessed portion being recessed from an outer surface of the wall body, and the first through hole extending inwardly from a bottom surface of the second recessed portion. At least a portion of the second sealing member is accommodated in the second recessed portion.

[0044] The second wall forms a convex inner and concave outer structure, which can increase the strength of the first shell wall and reduce the risk of deformation and cracking of the first shell wall. The second concave portion can also accommodate a portion of the second seal, thereby reducing the additional space occupied by the second seal in the axial direction of the first through hole, thereby improving space utilization.

[0045] In some embodiments, the second wall has a stepped surface. In the axial direction of the first through-hole, the stepped surface is closer to the outer surface of the wall body than the bottom surface of the second recess. The projection of the stepped surface along the axial direction of the first through-hole surrounds the projection of the bottom surface of the second recess along the axial direction of the first through-hole. The battery cell further includes a first seal, at least partially housed in the second recess and abutting against the stepped surface.

[0046] The stepped structure improves the overall structural strength of the second wall. The stepped surface and the bottom surface of the second recess respectively limit the first and second seals, reducing the risk of the second seal being compressed and extending between the first seal and the stepped surface. This, to a certain extent, prevents the second seal from interfering with the connection between the first seal and the second wall, thereby improving reliability.

[0047] In some embodiments, the battery cell further comprises a bracket, which is accommodated in the housing. The bracket is provided with a drainage recess connected to the first through hole, and the drainage recess is connected to the space between the main body and the bracket. In the axial direction of the first through hole, the first through hole is opposite to the bottom wall of the drainage recess.

[0048] The bottom wall of the drainage recess can withstand the impact of the electrolyte and guide the electrolyte flow within the drainage recess, thereby reducing the impact of the electrolyte on the main body and minimizing deformation of the main body's separator. The bracket also supports the outer shell to reduce the risk of the outer shell being deformed by external equipment during the electrolyte injection process, thereby improving the reliability of the battery cell.

[0049] In some embodiments, the housing includes a first housing wall, the first housing wall including a wall body and a first convex wall, at least a portion of the first convex wall protruding from a surface of the wall body facing the main body and located on one side of the main body along a first direction; the first convex wall includes a first wall body for defining a first through hole; at least a portion of the first wall body is accommodated in the drainage recess and spaced apart from a bottom wall of the drainage recess.

[0050] The drainage recess can also avoid the first wall, providing more space for the first wall and increasing the depth of the first through hole.

[0051] In some embodiments, the minimum diameter of the second through hole is smaller than the minimum diameter of the first through hole. During the liquid injection process, the second through hole is used to exhaust gas to stabilize the gas pressure. Gas is more fluid than liquid, so the second through hole can have a smaller diameter to reduce the loss of shell strength.

[0052] In some embodiments, the minimum aperture of the second through hole is equal to the minimum aperture of the first through hole. The first through hole and the second through hole are interchangeable, and an external device can inject electrolyte into the accommodating cavity through the first through hole or through the second through hole.

[0053] In some embodiments, the second through hole is used to inject electrolyte. The first through hole and the second through hole are used to inject electrolyte at the same time, which can improve the efficiency of electrolyte injection.

[0054] In some embodiments, the housing includes a shell and a cover plate, the shell having an opening, and the cover plate covers the opening. The first through hole and the second through hole are provided on the cover plate, thereby simplifying the molding process of the shell.

[0055] In some embodiments, the size of the housing along the first direction is L1, the size of the housing along the second direction is L2, and the size of the housing along the third direction is L3. The first direction, the second direction, and the third direction are perpendicular to each other. 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

[0056] On the premise that the volume of the battery cell is certain, limiting L1 / L3 to 1.2-18 and limiting L3 / L2 to 1.2-15 can balance the space utilization of the battery cell in the first direction and the current carrying capacity of the first tab, reduce the temperature rise of the battery cell, reduce the risk of deformation of the battery cell when subjected to external impact, and improve the reliability and cycle performance of the battery cell.

[0057] In a second aspect, the present application provides a battery comprising a plurality of battery cells provided by any embodiment of the first aspect.

[0058] In a third aspect, the present application provides an electrical device comprising the battery provided in any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0060] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0061] FIG2 is a schematic diagram of an explosion of a battery provided in some embodiments of the present application;

[0062] FIG3 is a schematic structural diagram of batteries provided in other embodiments of the present application;

[0063] FIG4 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0064] FIG5 is a schematic cross-sectional view of the battery cell shown in FIG4 taken along the AA direction;

[0065] FIG6 is a schematic structural diagram of an electrode assembly and a cover assembly of a battery cell provided in some embodiments of the present application;

[0066] FIG7 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided by some embodiments of the present application;

[0067] FIG8 is a schematic diagram of the first shell wall shown in FIG7 ;

[0068] FIG9 is a schematic top view of the first sealing member in FIG7 .

[0069] FIG10 is a schematic cross-sectional view of a second sealing member of a battery cell provided in some embodiments of the present application;

[0070] FIG11 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some other embodiments of the present application;

[0071] FIG12 is a schematic cross-sectional view of a second sealing member of a battery cell provided in some other embodiments of the present application;

[0072] FIG13 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in still other embodiments of the present application;

[0073] FIG14 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some further embodiments of the present application;

[0074] FIG15 is a schematic diagram of the first shell wall shown in FIG14;

[0075] FIG16 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some other embodiments of the present application;

[0076] FIG17 is a schematic structural diagram of a bracket provided in some embodiments of the present application;

[0077] FIG18 is a schematic structural diagram of the insulating bracket shown in FIG17 at another angle;

[0078] FIG19 is a schematic cross-sectional view taken along the BB direction of FIG18 .

[0079] The accompanying drawings are numbered as follows: 1. vehicle; 2. battery; 3. controller; 4. motor; 5. housing; 5a. first housing portion; 5b. second housing portion; 5c. storage space; 6. battery cell; 7. current collector; 10. electrode assembly; 11. main body; 12. first electrode tab; 13. second electrode tab; 20. housing; 20a. first through hole; 20b. second through hole; 20c. storage chamber; 21. housing; 22. cover plate; 23. first housing wall; 231. weak portion; 232. second recessed portion; 232a. bottom surface; 232b. stepped surface; 233. wall body; 234. first convex wall; 234a. first wall body; 234b. second wall body; 24. second housing wall; 25. housing recess; 30. first electrode lead-out member; 31. adapter; 32. electrode terminal; 33. terminal plate; 40. Second electrode lead-out member; 50. First sealing member; 51. First protrusion; 52. Connecting portion; 53. First recess; 60. Second sealing member; 61. Large end; 62. Small end; 63. Third recess; 70. Welding portion; 80. Bracket; 80a. Drainage recess; 80b. Bottom wall; 80c. Liquid injection opening; 80d. Accommodating recess; 81. Support block; 82. Insulating substrate; 83. First limiting plate; 84. Second limiting plate; 85. Third limiting plate; X, first direction; Z, second direction; Y, third direction. DETAILED DESCRIPTION

[0080] Below, with appropriate reference to the accompanying drawings, the embodiments of the sodium ion battery cell, battery, and electrical device of the present application are described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0081] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0082] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0083] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0084] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0085] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0086] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0087] In this application, the terms "plurality" and "multiple" refer to two or more.

[0088] Unless otherwise stated, the numerical values ​​of the various parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the examples of this application. Unless otherwise stated, the test temperature of each parameter is 25°C.

[0089] 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.

[0090] A battery cell typically includes an electrode assembly, which includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. For example, the electrode assembly also includes a separator disposed between the positive and negative electrodes. The separator prevents short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0091] Battery cells may include, but are not limited to, 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, and the like.

[0092] The battery cells may be prismatic battery cells or battery cells of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells or polygonal batteries. Polygonal batteries may be, for example, hexagonal batteries. Battery cells of other shapes may be cylindrical batteries.

[0093] The battery cells may be hard-shell battery cells, soft-pack battery cells, or other types of battery cells.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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 chassis of the vehicle, or part of the box body can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0098] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0099] During the production of battery cells, electrolytes need to be injected into the interior of the cells. Typically, this electrolyte injection process requires evacuating the interior of the battery cell first, then injecting the electrolyte into the cell using a pressure differential. This evacuation process takes a long time, resulting in slow electrolyte injection and poor electrolyte wetting of the electrode assembly, which impacts the production efficiency and cycle performance of the battery cells.

[0100] In view of this, an embodiment of the present application provides a technical solution, which opens a first through hole and a second through hole on the outer shell of the battery cell so that the electrolyte can be injected into the interior of the battery cell under normal pressure, thereby reducing the resistance to electrolyte injection, saving time, and improving the electrolyte wetting effect on the electrode assembly and the cycle performance of the battery cell.

[0101] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0102] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0103] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0104] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application.

[0105] As shown in FIG1 , a battery 2 is provided inside the vehicle 1. The battery 2 may be provided at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1. For example, the battery 2 may serve as an operating power source for the vehicle 1.

[0106] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0107] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0108] FIG2 is a schematic diagram of an explosion of a battery provided in some embodiments of the present application.

[0109] As shown in FIG. 2 , the battery 2 includes a case 5 and battery cells 6 (not shown). The battery cells 6 are accommodated in the case 5 .

[0110] The housing 5 is used to accommodate the battery cells 6 and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other and together define a storage space 5c for accommodating the battery cells 6. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0111] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0112] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0113] In the battery 2, there can be one or more battery cells 6. If there are multiple battery cells 6, the multiple battery cells 6 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections within the multiple battery cells 6. The multiple battery cells 6 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 6 can be housed within the housing 5. Alternatively, multiple battery cells 6 can be first connected in series, in parallel, or in a hybrid connection to form a battery module, and then the multiple battery modules can be connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 5.

[0114] FIG3 is a schematic structural diagram of batteries provided in other embodiments of the present application.

[0115] As shown in FIG3 , in some embodiments, the battery 2 includes a plurality of battery cells 6 and a plurality of busbar components 7 . The plurality of busbar components 7 can connect the plurality of battery cells 6 in series, in parallel, or in mixed connection.

[0116] Figure 4 is a structural schematic diagram of a battery cell provided in some embodiments of the present application; Figure 5 is a cross-sectional schematic diagram of the battery cell shown in Figure 4 taken along the AA direction; Figure 6 is a structural schematic diagram of the electrode assembly and cover assembly of the battery cell provided in some embodiments of the present application.

[0117] 4 to 6 , an embodiment of the present application provides a battery cell 6 , which includes an electrode assembly 10 and a housing 20 , wherein the electrode assembly 10 is disposed in the housing 20 .

[0118] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 6, active ions (e.g., lithium ions) are intercalated and released between the positive and negative electrodes. Optionally, the electrode assembly 10 also includes a separator disposed between the positive and negative electrodes. The separator can reduce the risk of short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0119] 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 layer disposed on at least one surface of the positive electrode current collector.

[0120] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0121] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, silver surface treated aluminum or stainless steel, 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.).

[0122] As an example, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide 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 material layers may also be used. These positive electrode active material layers 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 0.80 Co 0.15 Al 0.05O2) and at least one of its modified compounds, etc.

[0123] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, among others. When a metal foam is used as the positive electrode, a positive electrode active material layer may or may not be provided on the surface of the metal foam. For example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0124] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0125] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can 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.).

[0126] 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.

[0127] 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.

[0128] As an example, the negative electrode active material may adopt the negative electrode active material for battery cell 6 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 battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0129] 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.

[0130] In some embodiments, the separator includes a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0131] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. 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.

[0132] 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.

[0133] The housing 20 is a hollow structure, and its interior forms a space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a rectangular parallelepiped structure, a rectangular housing can be selected.

[0134] The housing 20 can be made of a variety of materials, for example, metal or plastic. Alternatively, the housing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0135] As an example, the housing 20 includes a shell 21 and a cover 22 . The shell 21 has an opening, and the cover 22 is used to cover the opening.

[0136] The housing 21 is a component used to cooperate with the cover plate 22 to form an internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0137] The housing 21 and the cover plate 22 may be separate components. For example, an opening may be provided on the housing 21 , and the cover plate 22 may cover the opening to form an internal cavity of the battery cell 6 .

[0138] The housing 21 can be of various shapes and sizes, such as a rectangular parallelepiped, a hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The housing 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0139] The shape of the cover plate 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the cover plate 22 can be the same as or different from the material of the housing 21. Optionally, the cover plate 22 can be made of a material with a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). In this way, the cover plate 22 is less likely to deform when subjected to compression or collision, thereby providing the battery cell 6 with higher structural strength and improved reliability.

[0140] The cover plate 22 can be connected to the housing 21 by welding, bonding, clamping or other methods.

[0141] FIG7 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some embodiments of the present application; FIG8 is a schematic diagram of the first shell wall shown in FIG7 ; and FIG9 is a top view schematic diagram of FIG7 at a first seal.

[0142] With reference to Figures 4 to 9 , some embodiments of the present application provide a battery cell 6 comprising an electrode assembly 10 and a housing 20. The housing 20 has a housing cavity 20c, in which the electrode assembly 10 is disposed. The electrode assembly 10 comprises a main body 11 and a first tab 12. The first tab 12 extends from one end of the main body 11 along a first direction X. The housing 20 is provided with a first through hole 20a and a second through hole 20b. The portion of the housing cavity 20c located on one side of the first tab 12 is connected to the first through hole 20a, and the portion of the housing cavity 20c located on the side of the main body 11 away from the first tab 12 is connected to the second through hole 20b. The first through hole 20a is used for injecting electrolyte.

[0143] The electrode assembly 10 is a component where electrochemical reactions occur in the battery cell 6. The housing 20 may contain one or more electrode assemblies 10. The electrode assembly 10 may be a wound structure, a laminate structure, a wound laminate composite structure, or other structures.

[0144] The shape of the electrode assembly 10 can be cylindrical, flat, or polygonal.

[0145] As an example, the electrode assembly 10 includes a first electrode piece, a second electrode piece, and an isolating member. The polarity of the first electrode piece is opposite to that of the second electrode piece. The isolating member is used to insulate and isolate the first electrode piece from the second electrode piece.

[0146] The first electrode sheet includes a first current collector and a first active material layer coated on the surface of the first current collector. The second electrode sheet includes a second current collector and a second active material layer coated on the surface of the second current collector. The main body 11 includes the portion of the first current collector coated with the first active material layer, the portion of the second current collector coated with the second active material layer, the first active material layer, and the second active material layer. The first electrode tab 12 includes the portion of the first current collector not coated with the first active material layer.

[0147] One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet.

[0148] There may be one or more first through holes 20a, and there may be one or more second through holes 20b.

[0149] The first through hole 20a can be a circular hole, a square hole, an elliptical hole, or a through hole of other shapes. The second through hole 20b can be a circular hole, a square hole, an elliptical hole, or a through hole of other shapes. The shape of the first through hole 20a can be the same as or different from the shape of the second through hole 20b.

[0150] The aperture of the first through hole 20 a may be greater than, smaller than, or equal to the aperture of the second through hole 20 b .

[0151] The axial direction of the first through hole 20 a may be parallel to the first direction X, or may intersect with the first direction X. For example, the axial direction of the first through hole 20 a may be perpendicular to the first direction X.

[0152] Exemplarily, both ends of the accommodating cavity 20c along the first direction X are connected to the first through hole 20a and the second through hole 20b respectively. Exemplarily, a portion of the accommodating cavity 20c located on the side of the main body 11 facing the first tab 12 is connected to the first through hole 20a.

[0153] In the embodiment of the present application, the first through hole 20a and the accommodating chamber 20c are connected, which means that, when the first through hole 20a is not blocked by other components, external substances (such as fluid) can enter the accommodating chamber 20c through the first through hole 20a; similarly, the fluid in the accommodating chamber 20c can also flow out of the housing 20 through the first through hole 20a. The second through hole 20b and the accommodating chamber 20c are connected, which means that, when the second through hole 20b is not blocked by other components, external substances (such as fluid) can enter the accommodating chamber 20c through the second through hole 20b; similarly, the fluid in the accommodating chamber 20c can also flow out of the housing 20 through the second through hole 20b.

[0154] The first through hole 20a can be used to inject electrolyte during the production of the battery cell 6, or can be used in other processes during the production of the battery cell 6. For example, during the formation process of the battery cell 6, gas generated inside the battery cell 6 can also be extracted through the first through hole 20a.

[0155] During the production process of the battery cell 6, electrolyte can be injected into the receiving cavity 20c through the first through-hole 20a. During the electrolyte injection process, the gas in the receiving cavity 20c can be discharged through the second through-hole 20b, allowing the electrolyte to be injected into the interior of the battery cell 6 under normal pressure, reducing the resistance to electrolyte injection, eliminating the conventional vacuum process, and thus improving efficiency. The first through-hole 20a and the second through-hole 20b are respectively connected to the spaces located on both sides of the main body 11 along the first direction X, so that the electrolyte can fully penetrate the main body 11 during the flow process, improving the electrolyte's wetting effect on the electrode assembly 10, and improving the cycle performance of the battery cell 6.

[0156] The end surface of the main body 11 facing the first electrode tab 12 usually has a gap. After the electrolyte flows into the accommodating cavity 20 c through the first through hole 20 a, it can penetrate into the interior of the main body 11 along the gap, thereby improving the electrolyte's wetting effect on the electrode assembly 10.

[0157] In some embodiments, after the electrolyte injection process is completed, the first through hole 20 a and the second through hole 20 b may be sealed with a sealant to isolate the accommodating cavity 20 c from the space outside the housing 20 .

[0158] In some embodiments, in the axial direction of the first through hole 20 a , the first electrode tab 12 and the main body 11 do not overlap with the first through hole 20 a .

[0159] The axial direction of the first through hole 20 a may refer to a direction parallel to the central axis of the first through hole 20 a .

[0160] In the axial direction of the first through hole 20a, the first electrode tab 12 does not overlap with the first through hole 20a, which may mean that the projection of the first electrode tab 12 along the axial direction does not overlap with the projection of the first through hole 20a along the axial direction. In the axial direction of the first through hole 20a, the main body 11 does not overlap with the first through hole 20a, which may mean that the projection of the main body 11 along the axial direction does not overlap with the projection of the first through hole 20a along the axial direction.

[0161] When the electrolyte passes through the first through hole 20a, the flow direction of the electrolyte is generally parallel to the axial direction of the first through hole 20a; the embodiment of the present application can reduce the risk of the electrolyte directly impacting the main body 11 and the first electrode tab 12 after flowing out of the first through hole 20a, thereby reducing the impact force on the first electrode tab 12 and the main body 11, reducing the deformation of the first electrode tab 12 and the main body 11, and improving the reliability of the battery cell 6.

[0162] In some embodiments, when injecting electrolyte, the first direction X can be made substantially parallel to the horizontal plane; in this case, the electrolyte is injected into the receiving cavity 20c through the first through hole 20a, and the second through hole 20b can play a role in stabilizing the gas pressure.

[0163] In some embodiments, when injecting electrolyte, the first direction X can be angled with the horizontal plane. For example, the first direction X can be perpendicular to the horizontal plane. In this case, the first through-hole 20a is positioned lower, and the electrolyte is injected through the first through-hole 20a. The second through-hole 20b can stabilize the gas pressure. Under the action of gravity, the electrolyte gradually enters the electrode assembly 10 from bottom to top. Combined with the siphon effect between the electrode pieces of the electrode assembly 10, the electrolyte can improve the wetting effect of the electrode assembly 10.

[0164] In some embodiments, the main body 11 further includes a second electrode tab 13, and the first electrode tab 12 and the second electrode tab 13 have opposite polarities. Exemplarily, the second electrode tab 13 includes a portion of the second current collector that is not coated with the second active material layer.

[0165] The second electrode tab 13 and the first electrode tab 12 may extend from the same end of the main body 11 along the first direction X, or may extend from two ends of the main body 11 along the first direction X respectively.

[0166] In some embodiments, the first electrode tab 12 and the second electrode tab 13 extend from both ends of the main body 11 along the first direction X, respectively, to reduce the risk of short circuit caused by contact between the first electrode tab 12 and the second electrode tab 13 .

[0167] The second through hole 20 b communicates with the space of the accommodating cavity 20 c located on the side of the main body 11 facing the second electrode tab 13 .

[0168] In some embodiments, the dimension of the housing 20 along the first direction X is L1, the dimension of the housing 20 along the second direction Z is L2, and the dimension of the housing 20 along the third direction Y is L3. The first direction X, the second direction Z, and the third direction Y are perpendicular to each other. 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

[0169] For example, the first direction X may be the length direction of the battery cell 6 , the second direction Z may be the thickness direction of the battery cell 6 , and the third direction Y may be the width direction of the battery cell 6 .

[0170] For example, L1 may be the maximum dimension of the housing 20 along the first direction X, L2 may be the maximum dimension of the housing 20 along the second direction Z, and L3 may be the maximum dimension of the housing 20 along the third direction Y.

[0171] The first tab 12 is disposed at the end of the electrode assembly 10 along the first direction X, occupying additional space in the first direction X. The larger L1 is, the smaller the size of the first tab 12 in the first direction X is, and the higher the space utilization of the battery cell 6 in the first direction X is. The larger L3 is, the larger the flow area of ​​the first tab 12 is, the better the flow capacity of the first tab 12 is, and the lower the heat generation is.

[0172] The smaller L2 is, the shorter the path for the electrode assembly 10 to dissipate heat to the outside is, and the lower the temperature rise of the battery cell 6 during charging and discharging is; however, the smaller L2 is, the thinner the battery cell 6 is, and the battery cell 6 is more likely to deform when subjected to external impact during the production, transportation and use of the battery cell 6.

[0173] On the premise that the volume of the battery cell 6 is certain, L1 / L3 is limited to 1.2-18 and L3 / L2 is limited to 1.2-15. This can balance the space utilization of the battery cell 6 in the first direction X and the current carrying capacity of the first electrode 12, reduce the temperature rise of the battery cell 6, reduce the risk of deformation of the battery cell 6 when subjected to external impact, and improve the reliability and cycle performance of the battery cell 6.

[0174] Alternatively, L1 / L3 may be 1.2, 2, 3, 4, 5, 7, 8, 10, 12, 14, 15, 17 or 18.

[0175] Alternatively, L3 / L2 may be 1.2, 2, 3, 4, 5, 7, 8, 10, 12, 14 or 15.

[0176] In some embodiments, L1 / L3 is 3-7. L3 / L2 is 2-7.

[0177] In some embodiments, L1 is 10 mm to 3000 mm. Alternatively, L1 is 100 mm to 1500 mm. Alternatively, L1 is 500 mm to 1000 mm.

[0178] As an example, L1 is 10 mm, 50 mm, 100 mm, 300 mm, 400 mm, 500 mm, 600 mm, 1000 mm, 1200 mm, 1500 mm, 2000 mm, 2500 mm or 3000 mm.

[0179] In some embodiments, L3 is 10 mm to 3000 mm. Alternatively, L3 is 30 mm to 1000 mm. L3 is 50 mm to 150 mm.

[0180] Optionally, L3 is 10 mm, 50 mm, 100 mm, 150 mm, 300 mm, 400 mm, 500 mm, 600 mm, 1000 mm, 1200 mm, 1500 mm, 2000 mm, 2500 mm or 3000 mm.

[0181] In some embodiments, L2 is 5 mm to 1000 mm. Alternatively, L2 is 10 mm to 300 mm. Alternatively, L2 is 20 mm to 50 mm.

[0182] Optionally, L3 is 5mm, 10mm, 10mm, 30mm, 50mm, 60mm, 80mm, 100mm, 200mm, 300mm, 500mm, 600mm, 800mm or 1000mm.

[0183] In some embodiments, when viewed along the third direction Y, the first through hole 20 a and the second through hole 20 b are respectively located on two sides of the main body 11 along the first direction X.

[0184] In some embodiments, the housing 20 includes a shell 21 and a cover 22 . The shell 21 has an opening, and the cover 22 covers the opening.

[0185] The first through hole 20a can be provided in the housing 21 or the cover 22. The second through hole 20b can be provided in the housing 21 or the cover 22.

[0186] Exemplarily, the first through hole 20 a and the second through hole 20 b are provided on the cover plate 22 , thereby simplifying the molding process of the housing 21 .

[0187] In some embodiments, the battery cell 6 further includes a first electrode lead 30 and a second electrode lead 40 . The first electrode lead 30 is disposed in the housing 20 and electrically connected to the first electrode tab 12 . The second electrode lead 40 is disposed in the housing 20 and electrically connected to the second electrode tab 13 .

[0188] The first electrode lead-out member 30 and the second electrode lead-out member 40 may be used to electrically connect the electrode assembly 10 to the current outside the battery cell 6 , thereby enabling charging and discharging of the battery cell 6 .

[0189] In some embodiments, the first electrode lead-out member 30 and the second electrode lead-out member 40 are both mounted on the cover plate 22 .

[0190] In some embodiments, the first electrode lead-out member 30 includes an adapter 31, an electrode terminal 32, and a terminal plate 33. The terminal plate 33 is located outside the cover plate 22. The adapter 31 is disposed in the accommodating cavity 20c and connected to the first electrode tab 12. The electrode terminal 32 passes through the cover plate 22 and connects the adapter 31 and the terminal plate 33. For example, the terminal plate 33 can be used to connect to a busbar. Optionally, the adapter 31 and the electrode terminal 32 are integrally formed.

[0191] In some embodiments, the cover plate 22, the first electrode lead-out member 30, the second electrode lead-out member 40 and other components can be pre-assembled into a cover plate assembly, and then the cover plate assembly is connected to the electrode assembly 10, and then the shell 21 is covered on the cover plate 22 and the cover plate 22 and the shell 21 are connected.

[0192] In some embodiments, the second through hole 20b is used to inject electrolyte. The first through hole 20a and the second through hole 20b are used to inject electrolyte at the same time, which can improve the efficiency of electrolyte injection.

[0193] In some embodiments, the minimum aperture of the second through hole 20 b is smaller than or equal to the minimum aperture of the first through hole 20 a .

[0194] For example, for a non-circular through hole, the area of ​​a certain cross section (i.e., the area of ​​a certain cross section perpendicular to the axial direction of the through hole) is K; then the aperture of the non-circular hole at the cross section is:

[0195] Correspondingly, the minimum aperture of the non-circular through hole is the aperture calculated based on the area of ​​the minimum cross section.

[0196] It is understood that the terms diameter, inner diameter, outer diameter, etc. described below are also applicable to non-circular structures. The diameter, inner diameter, outer diameter, etc. of non-circular structures can also be calculated using the area in the above manner.

[0197] In some embodiments, the minimum aperture of the second through hole 20b is equal to the minimum aperture of the first through hole 20a. Optionally, the second through hole 20b has the same shape and size as the first through hole 20a. In this way, the first through hole 20a and the second through hole 20b are interchangeable, and an external device can inject electrolyte into the accommodating cavity 20c through the first through hole 20a or through the second through hole 20b.

[0198] In some embodiments, the minimum diameter of the second through hole 20b is smaller than the minimum diameter of the first through hole 20a. During the liquid injection process, the second through hole 20b is used to exhaust gas to stabilize the gas pressure. Gas is more fluid than liquid, so the diameter of the second through hole 20b can be reduced to reduce the loss of strength of the housing 20.

[0199] In some embodiments, the first through hole 20 a and the second through hole 20 b are disposed diagonally to improve wettability of the electrode assembly 10 by the electrolyte.

[0200] Exemplarily, the housing 20 has four corners, and the first through hole 20 a and the second through hole 20 b are respectively disposed at two opposite corners.

[0201] In some embodiments, the housing 20 includes a first shell wall 23 and a second shell wall 24 arranged opposite to each other along a second direction Z, and the main body 11 is located between the first shell wall 23 and the second shell wall 24. The second direction Z is parallel to the thickness direction of the battery cell 6 and perpendicular to the first direction X.

[0202] The first wall 23 is a wall of the housing 20 having a certain thickness, and the second wall 24 is a wall of the housing 20 having a certain thickness. The first wall 23 and the second wall 24 are spaced apart from each other along the second direction Z.

[0203] The first shell wall 23 can be in various shapes, such as circular, rectangular, square or other shapes. The second shell wall 24 can be in various shapes, such as circular, rectangular, square or other shapes.

[0204] The first shell wall 23 can be a flat wall or a curved wall. The second shell wall 24 can be a flat wall or a curved wall.

[0205] For example, the area of ​​the second shell wall 24 may be equal to the area of ​​the first shell wall 23. For example, the second shell wall 24 and the first shell wall 23 have the same shape and size. Alternatively, the area of ​​the second shell wall 24 may be smaller than the area of ​​the first shell wall 23.

[0206] The first through hole 20a can be provided in the first shell wall 23 or the second shell wall 24. The second through hole 20b can be provided in the first shell wall 23 or the second shell wall 24, or other shell walls of the housing 20.

[0207] In some embodiments, the cover plate 22 includes a first shell wall 23 , and the housing 21 includes a second shell wall 24 .

[0208] In some embodiments, the first shell wall 23 is a flat wall, and the first through hole 20a is disposed in the first shell wall 23. The first shell wall 23 is located on one side of the electrode assembly 10 along the thickness direction, is relatively flat and has a large area, and is convenient for disposing the first through hole 20a.

[0209] In some embodiments, the axial direction of the first through hole 20a is parallel to the second direction Z.

[0210] In some embodiments, the first through hole 20a and the second through hole 20b are both disposed in the first shell wall 23. Optionally, the first through hole 20a and the second through hole 20b are respectively disposed in two opposite corners of the first shell wall 23, so that the first through hole 20a and the second through hole 20b are diagonally disposed.

[0211] In some embodiments, the minimum aperture of the first through hole 20 a is D1 , the dimension of the first shell wall 23 along the third direction Y is W, and the third direction Y is perpendicular to the first direction X and the second direction Z. 0.02≤D1 / W≤0.2.

[0212] Pore ​​size may refer to the diameter of a pore.

[0213] D1 is positively correlated with the efficiency of electrolyte injection. W is related to the difference in electrolyte wetting of the electrode assembly 10. For example, the larger W is, the greater the maximum distance between the first through hole 20a and the edge of the first shell wall 23 in the third direction Y. The closer to the first through hole 20a, the easier it is to be wetted.

[0214] In addition, the provision of the first through hole 20 a will affect the strength of the first shell wall 23 ; the larger D1 is, the lower the strength of the first shell wall 23 at the first through hole 20 a is.

[0215] In the embodiment of the present application, D1 / W is limited to greater than or equal to 0.02 to improve the efficiency of electrolyte injection and improve the consistency of electrolyte wetting of the electrode assembly 10. In the embodiment of the present application, D1 / W is limited to less than or equal to 0.2 to reduce the strength damage of the first shell wall 23 at the first through hole 20a, reduce the risk of cracking of the first shell wall 23 when the battery cell 6 is subjected to external impact, and improve reliability.

[0216] As examples, D1 / W may be 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.15, 0.18, or 0.2.

[0217] In some embodiments, D1 / W is 0.04-0.1.

[0218] In some embodiments, W may be a dimension of the cover plate 22 along the third direction Y.

[0219] In some embodiments, W may be equal to L3.

[0220] In some embodiments, 2 mm ≤ D1 ≤ 10 mm. Optionally, D1 is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0221] In the embodiment of the present application, D1 is limited to be greater than or equal to 2 mm to improve the injection efficiency of the electrolyte, and D1 is limited to be less than or equal to 10 mm to reduce the strength loss of the first shell wall 23 and lower the requirements for the injection equipment.

[0222] In addition, limiting D1 to greater than or equal to 2 mm can increase the flow area of ​​the first through hole 20a. In this way, the flow rate of the electrolyte can be reduced while the electrolyte injection speed meets the requirements, thereby reducing the impact force of the electrolyte on the main body 11, reducing the deformation of the main body 11, and improving the reliability of the battery cell 6.

[0223] In some embodiments, D1 is 3 mm to 8 mm. Alternatively, D1 is 5 mm to 7 mm.

[0224] In some embodiments, the battery cell 6 further includes a first sealing member 50 , which is connected to the housing 20 and is used to seal the first through hole 20 a .

[0225] The first sealing member 50 is used to seal the first through hole 20 a to reduce the risk of the accommodating cavity 20 c communicating with the external space of the battery cell 6 via the first through hole 20 a .

[0226] The first sealing member 50 may be inserted into the first through hole 20 a , or may be entirely located outside the first through hole 20 a .

[0227] The first sealing member 50 can be connected to the housing 20 by welding, bonding, clamping or other methods to seal the first through hole 20a.

[0228] The first sealing member 50 may be a plate-shaped structure, a columnar structure or other structures.

[0229] The first sealing member 50 may be made of metal, rubber or other materials.

[0230] In the embodiment of the present application, the first sealing member 50 is provided to seal the first through hole 20 a , thereby reducing the risk of electrolyte leakage through the first through hole 20 a and improving the reliability of the battery cell 6 .

[0231] In some embodiments, the first through hole 20 a is disposed in the first shell wall 23 , and the first sealing member 50 is connected to the first shell wall 23 .

[0232] In some embodiments, in the second direction Z, a projection of the first through hole 20 a is located within a projection of the first sealing member 50 .

[0233] In some embodiments, the first sealing member 50 includes a first protrusion 51 and a connecting portion 52 arranged around the first protrusion 51, the connecting portion 52 is located outside the shell 20 and connected to the shell 20, and the first protrusion 51 protrudes from the connecting portion 52 away from the surface of the shell 20.

[0234] The first protrusion 51 may be a solid structure or a hollow structure.

[0235] The first protrusion 51 can act as a reinforcing rib to improve the strength of the shell 20 at the first through hole 20a, reduce the risk of the shell 20 cracking around the first through hole 20a when the battery cell 6 is subjected to external impact, and improve the reliability of the battery cell 6.

[0236] In some embodiments, the connecting portion 52 is located outside the first shell wall 23 and connected to the first shell wall 23. The first protrusion 51 protrudes from a surface of the connecting portion 52 away from the first shell wall 23 along the second direction Z.

[0237] In some embodiments, the first sealing member 50 is provided with a first recessed portion 53 at a position corresponding to the first protruding portion 51 . The first recessed portion 53 is recessed relative to the surface of the connecting portion 52 facing the housing 20 .

[0238] By providing the first recess 53 , the weight of the first sealing member 50 can be reduced, and the energy density of the battery cell 6 can be increased.

[0239] Exemplarily, the first recess 53 is recessed relative to the surface of the connecting portion 52 facing the first housing wall 23 .

[0240] For example, the first sealing member 50 can be made by punching a plate-like structure, where the first convex portion 51 and the first concave portion 53 are formed at the pressed position of the plate-like structure.

[0241] In some embodiments, by providing the first sealing member 50 having the first protrusion 51 , the overall strength of the housing 20 can be improved, and the aperture of the first through hole 20 a can be appropriately increased to improve the injection efficiency of the electrolyte.

[0242] In some embodiments, in the axial direction of the first through hole 20 a , a dimension H2 of the first protrusion 51 protruding from the outer surface of the first shell wall 23 satisfies: 0.5 mm ≤ H2 ≤ 2 mm.

[0243] Optionally, H2 is 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm.

[0244] In this embodiment of the present application, H2 is defined as greater than or equal to 0.5 mm to increase the strength of the first seal 50, compensate for the strength of the outer shell 20, reduce the risk of cracking of the outer shell 20, and improve the reliability of the battery cell 6. H2 is defined as less than or equal to 2 mm to reduce the additional space occupied by the first seal 50 in the axial direction of the first through hole 20a, thereby reducing the loss of energy density of the battery cell 6.

[0245] In some embodiments, in the second direction Z, the first protrusion 51 protrudes from the outer surface of the first shell wall 23 by a dimension H2.

[0246] In some embodiments, the battery cell 6 further includes a second sealing member 60 , a portion of which is inserted into the first through hole 20 a .

[0247] The second sealing member 60 and the first sealing member 50 can function as a double-layer seal, thereby improving the sealing performance, reducing the risk of electrolyte leakage, and improving the reliability of the battery cell 6 .

[0248] In some embodiments, the second sealing member 60 is detachably connected to the first housing wall 23 .

[0249] The second seal 60 can serve as a temporary seal during the production process of the battery cell 6. For example, after the electrolyte injection process is completed, the second seal 60 can be inserted into the first through-hole 20a to seal the first through-hole 20a, and then the battery cell 6 can be transported to another station. When the first through-hole 20a needs to be reused (for example, during the formation process, the gas generated by the side reaction inside the battery cell 6 can be extracted through the first through-hole 20a), the second seal 60 can be removed and the battery cell 6 can be processed.

[0250] After all processes related to the first through hole 20 a are completed, the first sealing member 50 is mounted on the first housing wall 23 .

[0251] In some embodiments, a portion of the second sealing member 60 is inserted into the first through hole 20 a , and another portion of the second sealing member 60 is received in the first recess 53 .

[0252] The first recess 53 can not only avoid the second seal 60 , but also limit and fix the second seal 60 , thereby reducing the risk of the second seal 60 loosening when the battery cell 6 is subjected to external impact, and improving the sealing and reliability of the battery cell 6 .

[0253] In some embodiments, a housing recess 25 is provided on the outer side of the housing 20 .

[0254] By providing the housing recess 25 , the volume of the battery cell 6 can be reduced and the energy density can be increased.

[0255] In some embodiments, in the second direction Z, the first sealing member 50 is located on a side of the housing 20 away from the housing recess 25 .

[0256] When the plurality of battery cells 6 are arranged along the second direction Z, the housing recess 25 of one battery cell 6 can avoid the first sealing member 50 of another battery cell 6 , thereby improving space utilization and enhancing the energy density of the battery.

[0257] In some embodiments, the housing recess 25 is recessed relative to the surface of the second housing wall 24 facing away from the main body 11. Optionally, in the second direction Z, the projection of the first sealing member 50 is located within the projection of the housing recess 25.

[0258] In some embodiments, the battery cell 6 is provided with two housing recesses 25 , and the two housing recesses 25 are respectively located on two sides of the second housing 21 along the first direction X.

[0259] In some embodiments, in the second direction Z, the projection of the portion of the first electrode lead-out member 30 located outside the first shell wall 23 is located within the projection of a shell recess 25 , and the projection of the portion of the second electrode lead-out member 40 located outside the first shell wall 23 is located within the projection of a shell recess 25 .

[0260] For example, when two battery cells 6 are arranged along the second direction Z, the two housing recesses 25 of one battery cell 6 may respectively avoid the first electrode lead-out member 30 and the second electrode lead-out member 40 of the other battery cell 6 .

[0261] In some embodiments, the second through hole 20b is provided in the first shell wall 23. Exemplarily, the axial direction of the second through hole 20b is parallel to the second direction Z.

[0262] In some embodiments, in the second direction Z, the projection of the first through hole 20 a is located within the projection of the bottom wall of one housing recess 25 , and the projection of the second through hole 20 b is located within the projection of the bottom wall of another housing recess 25 .

[0263] In some embodiments, the first sealing member 50 is welded to the housing 20 to form a welding portion 70. Welding can increase the connection strength between the first sealing member 50 and the housing 20 and improve the sealing performance.

[0264] Exemplarily, the first sealing member 50 is connected to the first housing wall 23 by laser welding to form a welding portion 70 .

[0265] In some embodiments, the housing 20 is provided with a pressure relief mechanism, which may be one or more.

[0266] The pressure relief mechanism significantly impacts the reliability of the battery cell 6. For example, short circuits, overcharging, and other events can cause thermal runaway within the battery cell 6, leading to a sudden increase in pressure. In these situations, the pressure relief mechanism activates to release the internal pressure, reducing the risk of explosion or fire in the battery cell 6.

[0267] The pressure relief mechanism is a component or element that activates to release the internal pressure of the battery cell 6 when the internal pressure reaches a predetermined threshold. This threshold varies depending on the design requirements. It may depend on the materials of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 6.

[0268] In some embodiments, the first shell wall 23 is provided with a pressure relief mechanism.

[0269] In some examples, the first shell wall 23 and the pressure relief mechanism may be integrally formed. In alternative examples, the pressure relief mechanism and the first shell wall 23 are independently formed components that may be connected by welding, bonding, or other means. For example, the first shell wall 23 may be provided with a pressure relief hole that extends through the first shell wall 23. The pressure relief mechanism may be mounted on the first shell wall 23 and cover the pressure relief hole, thereby separating the inner and outer spaces of the first shell wall 23.

[0270] In some embodiments, the first shell wall 23 is integrally formed with the pressure relief mechanism.

[0271] In some embodiments, the first shell wall 23 is provided with a weak portion 231. Exemplarily, by providing the weak portion 231, a pressure relief mechanism is formed on the first shell wall 23.

[0272] The strength of the weak portion 231 is lower than that of other portions of the first shell wall 23 . The weak portion 231 is a portion that is easily broken, shattered, torn or opened.

[0273] In some examples, a groove, notch, or other structure may be provided in a predetermined region of the first shell wall 23 to reduce the local strength of the first shell wall 23, thereby forming a weak portion 231 on the first shell wall 23. For example, a thinning process may be performed on the predetermined region of the first shell wall 23, and the thinned portion of the first shell wall 23 forms the weak portion 231. In other examples, a material treatment may be performed on the predetermined region of the first shell wall 23 to make the strength of the region weaker than that of other regions. In other words, the region serves as the weak portion 231.

[0274] When thermal runaway occurs in the battery cell 6, the weak portion 231 may rupture under the action of the internal pressure or temperature of the battery cell 6 to form a channel for releasing the internal pressure, thereby releasing the pressure in time, reducing the risk of fire or explosion of the battery cell 6, and improving the reliability of the battery cell 6.

[0275] In some embodiments, there may be four weak portions 231 , and the four weak portions 231 may be respectively disposed at the four corners of the first shell wall 23 .

[0276] In some embodiments, the housing 20 is provided with a weak portion 231 , and a minimum distance D3 between the welding portion 70 and the weak portion 231 is greater than or equal to 1 mm.

[0277] During welding, heat is conducted to the surrounding area of ​​the molten pool, creating a heat-affected zone (HAZ). In this embodiment, D3 is limited to 1 mm or greater to minimize the impact of the HAZ on the weak portion 231, reduce the thermal stress on the weak portion 231 after welding, lower the risk of rupture and failure of the weak portion 231, and improve the reliability of the battery cell 6.

[0278] Optionally, D3 is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm or 10 mm.

[0279] Exemplarily, D3 is greater than or equal to 2 mm.

[0280] In some embodiments, the area of ​​the welding portion 70 is S1, the area of ​​the minimum cross section of the first through hole 20a perpendicular to its own axial direction is S2, and 1.5≤S1 / S2≤5.

[0281] For example, S2=π×(D1 / 2) 2 .

[0282] The larger S2 is, the higher the requirement for the connection strength between the first sealing member 50 and the housing 20 is, that is, the higher the requirement for S1 is. Of course, the larger S1 is, the higher the risk of the weld 70 causing thermal impact on other structures is.

[0283] In view of this, the embodiment of the present application limits S1 / S2 to greater than or equal to 1.5 to increase the connection strength between the first seal 50 and the outer shell 20, improve the structural strength of the battery cell 6 around the first through hole 20a, and reduce the risk of cracking of the outer shell 20 around the first through hole 20a. The embodiment of the present application limits S1 / S2 to less than or equal to 5 to limit the heat-affected zone caused by welding and reduce the risk of failure of other structures of the battery cell 6 (such as the weak portion 231 and the first electrode lead-out member 30) under the action of thermal stress.

[0284] Optionally, S1 / S2 is 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5.

[0285] Optionally, S1 / S2 is 2.5-4.

[0286] In some embodiments, the welding portion 70 is annular and can function as a seal, thereby reducing the risk of external impurities entering the first through hole 20 a from between the first sealing member 50 and the first shell wall 23 .

[0287] For example, the outer diameter of the welding portion 70 is D2, and the inner diameter of the welding portion 70 is D7. S1 = π × (D2 / 2) 2 -π×(D7 / 2) 2 .

[0288] In some embodiments, the outer diameter of the welding portion 70 is D2, the minimum diameter of the first through hole 20a is D1, and 1.6≤D2 / D1≤2.5.

[0289] In this embodiment of the present application, D2 / D1 is limited to greater than or equal to 1.6 to increase the strength of the weld 70, improve the structural strength of the battery cell 6 around the first through hole 20a, and reduce the risk of cracking of the outer shell 20 around the first through hole 20a. In this embodiment of the present application, D2 / D1 is limited to less than or equal to 2.5 to limit the heat-affected zone caused by welding and reduce the risk of failure of other structures of the battery cell 6 due to thermal stress.

[0290] Optionally, D2 / D1 is 1.6, 1.8, 2, 2.2, 2.4 or 2.5.

[0291] Optionally, D2 / D1 is 1.8-2.2.

[0292] In some embodiments, the housing 20 has a second recess 232, and the first through hole 20a extends inward from a bottom surface 232a of the second recess 232. For example, the first through hole 20a extends inward from the bottom surface 232a of the second recess 232 along the second direction Z.

[0293] When injecting electrolyte, the bottom surface 232 a of the second recess 232 can play a positioning role, and the injection device can be against the bottom surface 232 a of the second recess 232 to reduce the outward splashing of electrolyte.

[0294] In some embodiments, the housing 20 includes a first housing wall 23. The first housing wall 23 includes a wall body 233 and a first protruding wall 234. At least a portion of the first protruding wall 234 protrudes from a surface of the wall body 233 facing the main body 11 and is located on one side of the main body 11 along the first direction X. The first protruding wall 234 includes a first wall body 234a for defining the first through hole 20a.

[0295] By providing the inwardly protruding first convex wall 234 , the depth of the first through hole 20 a can be increased, the structural strength of the first shell wall 23 around the first through hole 20 a can be improved, and the deformation of the first shell wall 23 can be reduced.

[0296] In some embodiments, a projection of the main body 11 along the second direction Z is located within a projection of the wall body 233 along the second direction Z.

[0297] In some embodiments, the wall body 233 is in the shape of a flat plate.

[0298] In some embodiments, the thickness direction of the wall body 233 is parallel to the second direction Z.

[0299] In some embodiments, a projection of the first wall 234 a along the first direction X is located within a projection of the main body 11 along the first direction X.

[0300] In some embodiments, the dimension of the first wall 234a along the second direction Z is H1, the minimum aperture of the first through hole 20a is D1, and 0.2≤H1 / D1≤1. The second direction is parallel to the thickness direction of the wall body.

[0301] In this embodiment of the present application, H1 / D1 is limited to greater than or equal to 0.2 to increase the structural strength and stability of the first wall 234a and reduce the risk of deformation and cracking of the first wall 234a. In this embodiment of the present application, H1 / D1 is limited to less than or equal to 1 to reduce the space occupied by the first wall 234a within the housing 20, reduce the resistance to the flow of electrolyte within the housing 20, and improve the injection efficiency.

[0302] Optionally, H1 / D1 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.

[0303] Optionally, H1 / D1 is 0.3-0.6.

[0304] In some embodiments, H1 is 0.5 mm to 10 mm. Alternatively, H1 is 1 mm to 5 mm.

[0305] As an example, H1 is 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 5 mm, 6 mm, 8 mm, or 10 mm.

[0306] In some embodiments, the battery cell 6 further includes a second sealing member 60 , at least a portion of which is inserted into the first through hole 20 a and detachably connected to the first protruding wall 234 .

[0307] The second sealing member 60 can be used to seal the first through-hole 20a, improving the sealing performance of the battery cell 6. The second sealing member 60 can be disassembled and assembled multiple times during the production process of the battery cell 6, facilitating multiple processing steps of the battery cell 6 through the first through-hole 20a. The first convex wall 234 has a large dimension in the second direction Z, and connecting the second sealing member 60 to the first convex wall 234 can improve the connection strength.

[0308] In some embodiments, the second sealing member 60 is interference-fitted with the first through hole 20 a , which can effectively seal the first through hole 20 a and facilitate assembly and disassembly of the second sealing member 60 .

[0309] In some embodiments, the second sealing member 60 is made of an elastic material. Alternatively, the second sealing member 60 is made of rubber.

[0310] In some embodiments, the first through hole 20 a and the second through hole 20 b have the same structure.

[0311] Exemplarily, the first housing wall 23 further includes a second convex wall (not shown), at least a portion of which is used to define the second through hole 20 b. Exemplarily, the structure of the second convex wall is the same as that of the first convex wall 234.

[0312] Exemplarily, the battery cell 6 further includes a third sealant (not shown) and a fourth sealant (not shown) for sealing the second through hole 20b. Optionally, the structure of the third sealant may be the same as that of the first sealant 50, and the structure of the fourth sealant may be the same as that of the second sealant 60.

[0313] FIG10 is a schematic cross-sectional view of a second sealing member of a battery cell provided in some embodiments of the present application.

[0314] 7 to 10 , in some embodiments, the second sealing member 60 has a large end 61 and a small end 62 that are axially opposed to each other along the first through hole, with the small end 62 located inboard of the large end 61. The ratio of the diameter D4 of the small end 62 to the minimum aperture D1 of the first through hole 20a is 0.95-1.05, and the diameter D5 of the large end 61 is greater than the maximum aperture of the first through hole 20a.

[0315] In the embodiment of the present application, the large end 61 is not required to be the part with the largest diameter of the second seal 60, as long as its diameter is larger than the diameter of the small end 62; similarly, the small end 62 is not required to be the part with the smallest diameter of the second seal 60.

[0316] In the embodiment of the present application, D4 / D1 is limited to 0.95-1.05 to facilitate the insertion of the second seal 60 into the first through hole 20a; the large end 61 of the second seal 60 has a larger size, which can reduce the risk of the second seal 60 falling into the accommodating cavity 20c through the first through hole 20a, and effectively cover the first through hole 20a, thereby improving the sealing performance.

[0317] In some embodiments, D5 / D1 is 1.15-1.4.

[0318] In some embodiments, H1 is greater than or equal to 1 mm, so as to increase the contact dimension between the second sealing member 60 and the first wall 234 a along the second direction Z and improve the stability of the second sealing member 60 .

[0319] In some embodiments, the second sealing member 60 is truncated cone-shaped. Optionally, the second sealing member 60 has a taper of 9-20 degrees, thereby reducing the difficulty of inserting the second sealing member 60 into the first through hole 20a and improving the interference effect between the second sealing member 60 and the first through hole 20a.

[0320] In some embodiments, the large end 61 of the second sealing member 60 is accommodated in the first recess 53 of the first sealing member 50. The first recess 53 can limit the large end 61 of the second sealing member 60, restrict the loosening of the second sealing member 60, and reduce the risk of interference failure between the second sealing member 60 and the first through hole 20a.

[0321] In some embodiments, the edge of the large end 61 of the second sealing member 60 is chamfered to match the chamfer of the edge of the first recess 53 .

[0322] In some embodiments, the first seal 50 presses against the second seal 60 in the second direction Z.

[0323] In some embodiments, the first sealing member 50 is located outside the wall body 233 , and the connecting portion 52 of the first sealing member 50 is in contact with the outer surface of the wall body 233 .

[0324] In some embodiments, the first protruding wall 234 further includes a second wall 234b, which surrounds the first wall 234a and connects the wall body 233 and the first wall 234a. The second wall 234b protrudes inward from the wall body 233 and defines a second recess 232. The second recess 232 is recessed from the outer surface of the wall body 233. The first through hole 20a extends inward from the bottom surface 232a of the second recess 232. At least a portion of the second sealing member 60 is accommodated in the second recess 232.

[0325] The second wall 234b has a convex inner and concave outer structure, which can increase the strength of the first shell wall 23 and reduce the risk of deformation and cracking of the first shell wall 23. The second recess 232 can also accommodate a portion of the second seal 60, thereby reducing the additional space occupied by the second seal 60 in the axial direction of the first through hole, thereby improving space utilization.

[0326] In some embodiments, the end portion of the first wall 234 a connected to the second wall 234 b is bent into an arc-shaped structure to disperse stress during the forming process of the first convex wall 234 .

[0327] In some embodiments, in any direction perpendicular to the second direction Z, the minimum distance between the second recess 232 and the weak portion 231 is greater than or equal to 2 mm.

[0328] FIG11 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some other embodiments of the present application; FIG12 is a cross-sectional schematic diagram of a second sealing member of a battery cell provided in some other embodiments of the present application.

[0329] 11 and 12 , in some embodiments, an annular third recess 63 is defined on the outer periphery of the second sealing member 60 , and at least a portion of the first wall 234 a is accommodated in the third recess 63 .

[0330] The first wall 234a can be embedded in the third recess 63 and form a riveted structure with the second sealing member 60, so that the first wall 234a can limit the movement of the second sealing member 60 in the second direction Z, thereby improving the stability of the second sealing member 60 and the sealing performance.

[0331] In some embodiments, the bottom surface of the third recess 63 is in contact with the first wall 234 a.

[0332] In some embodiments, after the second sealing member 60 is inserted into the first through hole 20 a , the third recess 63 may be deformed under the pressure of the first wall 234 a .

[0333] FIG13 is a schematic partial cross-sectional view of a battery cell at a first through hole provided in some other embodiments of the present application.

[0334] As shown in FIG13 , in some embodiments, the first sealing member 50 may be a flat plate structure. The flat plate structure can reduce the space occupied by the first sealing member 50 in the second direction Z and simplify the molding process of the first sealing member 50 .

[0335] FIG14 is a partial cross-sectional schematic diagram of a battery cell at a first through hole provided in some further embodiments of the present application; FIG15 is a schematic diagram of the first shell wall shown in FIG14 .

[0336] As shown in FIG. 14 and FIG. 15 , in some embodiments, at least a portion of the first sealing member 50 is configured to be received in the second recess 232 .

[0337] When assembling the first seal 50, the second recess 232 can play a positioning role, thereby simplifying the assembly process of the first seal 50. By providing the second recess 232, the additional space occupied by the first seal 50 in the axial direction of the first through hole can also be reduced, thereby improving space utilization.

[0338] In some embodiments, the second wall 234b has a stepped surface 232b. In the axial direction of the first through-hole, the stepped surface 232b is closer to the outer surface of the wall body 233 than the bottom surface 232a of the second recess 232. The projection of the stepped surface 232b along the axial direction of the first through-hole surrounds the projection of the bottom surface 232a of the second recess 232 along the axial direction of the first through-hole. At least a portion of the first sealing member 50 is accommodated in the second recess 232 and abuts against the stepped surface 232b.

[0339] The stepped structure improves the overall structural strength of the second wall 234b. The stepped surface 232b and the bottom surface 232a of the second recess 232 respectively limit the first seal 50 and the second seal 60, reducing the risk of the second seal 60 being compressed and extending between the first seal 50 and the stepped surface 232b. This, to a certain extent, prevents the second seal 60 from interfering with the connection between the first seal 50 and the second wall 234b, thereby improving reliability.

[0340] In some embodiments, the connecting portion 52 is entirely received in the second recess 232 .

[0341] In some embodiments, the distance between the outer surface of the wall body 233 and the stepped surface 232 b is 0.3 mm-1 mm in the second direction Z. Optionally, the distance between the outer surface of the wall body 233 and the stepped surface 232 b is 0.3 mm, 0.5 mm, 0.7 mm, 0.8 mm, or 1 mm.

[0342] In some embodiments, the area of ​​the step surface 232 b is S3 , and S3 / S2 is 1.5-5.

[0343] In this embodiment of the present application, S3 / S2 is limited to greater than or equal to 1.5 to increase the welding area between the first seal 50 and the second wall 234b and improve the connection strength. In this embodiment of the present application, S3 / S2 is limited to less than or equal to 5 to limit the total area of ​​the second recess 232 and reduce the risk of interference between the first convex wall 234 and other structures of the battery cell 6.

[0344] In some embodiments, the step surface 232b is a circular plane.

[0345] In some embodiments, optionally, S3 / S2 is 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5. Optionally, S3 / S2 is 2.5-4.

[0346] In some embodiments, the maximum diameter of the second recess 232 is D6. D6 / D1 may be 1.6-2.5.

[0347] In this embodiment of the present application, D6 / D1 is limited to greater than or equal to 1.6 to increase the welding area between the first seal 50 and the second wall 234b, improve the structural strength of the battery cell 6 around the first through hole 20a, and reduce the risk of cracking of the first shell wall 23 around the first through hole 20a. In this embodiment of the present application, D6 / D1 is limited to less than or equal to 2.5 to limit the total area of ​​the second recess 232 and reduce the risk of interference between the first convex wall 234 and other structures of the battery cell 6.

[0348] Optionally, D6 / D1 is 1.6, 1.8, 2, 2.2, 2.4 or 2.5.

[0349] Optionally, D6 / D1 is 1.8-2.2.

[0350] Figure 16 is a partial cross-sectional schematic diagram of a battery cell at the first through hole provided in some other embodiments of the present application; Figure 17 is a structural schematic diagram of a bracket provided in some embodiments of the present application; Figure 18 is a structural schematic diagram of the insulating bracket shown in Figure 17 at another angle; Figure 19 is a cross-sectional schematic diagram of Figure 18 taken along the BB direction.

[0351] Referring to Figures 5 and 16-19 , in some embodiments, the battery cell 6 further includes a bracket 80 having a drainage recess 80a connected to the first through hole 20a. The drainage recess 80a is connected to the space between the main body 11 and the bracket 80. In the axial direction of the first through hole 20a, the first through hole 20a is opposite to the bottom wall 80b of the drainage recess.

[0352] The bottom wall 80b of the drainage recess can withstand the impact of the electrolyte and guide the electrolyte to flow within the drainage recess 80a, thereby reducing the impact of the electrolyte on the main body 11 and reducing the deformation of the separator of the main body 11. The bracket 80 can also support the outer shell 20 to reduce the risk of the outer shell 20 being compressed and deformed by external equipment during the electrolyte injection process, thereby improving the reliability of the battery cell 6.

[0353] In some embodiments, the bracket 80 and the main body 11 are arranged along the first direction X.

[0354] In some embodiments, a drainage recess 80 a is provided on a side of the bracket 80 facing the first shell wall 23 .

[0355] In some embodiments, the housing 20 includes a first housing wall 23. The first housing wall 23 includes a wall body 233 and a first protruding wall 234. At least a portion of the first protruding wall 234 protrudes from a surface of the wall body 233 facing the main body 11 and is located on one side of the main body 11 along the first direction X. The first protruding wall 234 includes a first wall body 234a for defining the first through hole 20a. At least a portion of the first wall body 234a is accommodated in the drainage recess 80a and is spaced apart from the bottom wall 80b of the drainage recess.

[0356] The drainage recess 80a can also avoid the first wall 234a, provide more space for the first wall 234a, and increase the depth of the first through hole 20a.

[0357] In some embodiments, the bracket 80 is an insulating bracket.

[0358] In some embodiments, the drainage recess 80a forms a liquid injection opening 80c on the surface of the bracket 80 facing the main body 11. The electrolyte can flow out through the liquid injection opening 80c and infiltrate the main body 11.

[0359] In some embodiments, a portion of the second sealing member 60 extends into the drainage recess 80a. Exemplarily, the small end 62 is received in the drainage recess 80a.

[0360] In some embodiments, the bracket 80 fits against the wall body 233 , thereby supporting the wall body 233 and reducing deformation of the wall body 233 .

[0361] In some embodiments, the bracket 80 is fixed to the wall body 233 .

[0362] In some embodiments, a receiving recess 80d is provided on the side of the bracket 80 facing the main body 11. At least a portion of the first tab 12 is received in the receiving recess 80d. The bracket 80 can accommodate the first tab 12 and isolate at least a portion of the first tab 12 from the housing 20 to reduce the risk of short circuits. The receiving recess 80d can also gather the first tab 12, reducing the risk of the first tab 12 becoming disjointed.

[0363] In some embodiments, the bracket 80 includes two supporting blocks 81 , and in the third direction Y, the accommodating recess 80 d is located between the two supporting blocks 81 .

[0364] In some embodiments, the drainage recess 80 a is disposed on a support block 81 . The support block 81 separates the drainage recess 80 a from the receiving recess 80 d to reduce the risk of the electrolyte directly impacting the first electrode tab 12 .

[0365] In some embodiments, each support block 81 is provided with a weight-reducing hole.

[0366] In some embodiments, the bracket 80 includes an insulating base plate 82, a first limiting plate 83, a second limiting plate 84, and a third limiting plate 85. The first limiting plate 83, the second limiting plate 84, and the third limiting plate 85 are all located on a side of the insulating base plate 82 facing the main body 11 and are sequentially spaced apart along the second direction Z. The third limiting plate 85 is closer to the first housing wall 23 than the first limiting plate 83 and the second limiting plate 84.

[0367] In the third direction Y, the first limiting plate 83, the second limiting plate 84 and the third limiting plate 85 are all located between the two support blocks 81. The two support blocks 81, the first limiting plate 83, the second limiting plate 84 and the insulating substrate 82 define an accommodating recess 80d.

[0368] At least a portion of the third limiting plate 85 is located between the adapter 31 and the first casing wall 23 to fix the bracket 80 to the first casing wall 23 .

[0369] According to some embodiments of the present application, the present application also provides a battery comprising a plurality of battery cells according to any of the above embodiments.

[0370] According to some embodiments of the present application, the present application further provides an electrical device comprising a battery cell according to any of the above embodiments, the battery cell being used to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems using the battery cell.

[0371] 4 to 10 , an embodiment of the present application provides a battery cell 6 , which includes an electrode assembly 10 , a housing 20 , a first sealing member 50 , and a second sealing member 60 .

[0372] The electrode assembly 10 includes a main body 11 , a first electrode tab 12 and a second electrode tab 13 . The first electrode tab 12 and the second electrode tab 13 have opposite polarities and extend from both ends of the main body 11 along a first direction X, respectively.

[0373] The housing 20 includes a shell 21 and a cover plate 22 . The shell 21 is provided with an opening on one side along the second direction Z. The cover plate 22 covers the opening and defines a receiving cavity 20 c together with the shell 21 .

[0374] The cover plate 22 includes a wall body 233, a first convex wall 234, and a second convex wall. The first convex wall 234 and the second convex wall protrude from a surface of the wall body 233 facing the main body 11. The first convex wall 234 and the second convex wall are respectively located on both sides of the main body 11 along the first direction X. Exemplarily, the first convex wall 234 and the second convex wall are arranged along the diagonal direction of the cover plate 22.

[0375] The first convex wall 234 includes a first wall body 234a and a second wall body 234b. The first wall body 234a defines a first through hole 20a. The second wall body 234b is disposed around the first wall body 234a and connects the wall body 233 and the first wall body 234a. The second wall body 234b protrudes inward from the wall body 233 and is used to define a second recess 232. The second recess 232 is recessed from the outer surface of the wall body 233. The first through hole 20a extends inward from the bottom surface 232a of the second recess 232. For example, the structure of the second convex wall is the same as that of the first convex wall 234.

[0376] The second sealing member 60 is inserted into the first through hole 20a and seals the first through hole 20a. The first sealing member 50 is welded to the wall body 233 and is located outside the second sealing member 60, thereby sealing the first through hole 20a.

[0377] At least a portion of the second convex wall defines a second through hole 20b. The portion of the accommodating cavity 20c located on the side of the main body 11 facing the first electrode tab 12 communicates with the first through hole 20a, and the portion of the accommodating cavity 20c located on the side of the main body 11 facing the second electrode tab 13 communicates with the second through hole 20b. The first through hole 20a is used for injecting electrolyte, and the second through hole is used for exhausting gas during the electrolyte injection process.

[0378] In the axial direction of the first through hole 20a, the first electrode tab 12 and the main body 11 do not overlap with the first through hole 20a. In the axial direction of the second through hole 20b, the second electrode tab 13 and the main body 11 do not overlap with the second through hole 20b. The axial directions of the first through hole 20a and the second through hole 20b are both parallel to the second direction Z.

[0379] 4 to 10 , an embodiment of the present application provides a battery cell 6 , which includes an electrode assembly 10 , a housing 20 , and a first sealing member 50 .

[0380] The electrode assembly 10 includes a main body 11 and a first electrode tab 12 . The main body 11 includes a first end surface and a second end surface opposite to each other along a first direction X. The first electrode tab 12 extends from the first end surface.

[0381] The housing 20 has a housing cavity 20c, into which the electrode assembly 10 is disposed. The housing 20 is provided with a first through-hole 20a and a second through-hole 20b. The first through-hole 20a and the second through-hole 20b are located on either side of the main body 11 along the first direction X. The portion of the housing cavity 20c located on the side of the first electrode tab 12 communicates with the first through-hole 20a, while the portion of the housing cavity 20c located on the side of the main body 11 facing away from the first electrode tab 12 communicates with the second through-hole 20b. The first through-hole 20a is used to inject electrolyte. In the axial direction of the first through-hole 20a, neither the first electrode tab 12 nor the main body 11 overlaps with the first through-hole 20a. The shell 20 includes a first shell wall 23, the first shell wall 23 includes a wall body 233 and a first convex wall 234, at least part of the first convex wall 234 protrudes from the surface of the wall body 233 facing the main body 11 and is located on one side of the main body 11 along the first direction X, and the first convex wall 234 includes a first wall body 234a for defining a first through hole 20a.

[0382] The first sealing member 50 includes a first protrusion 51 and a connecting portion 52 disposed around the first protrusion 51. The connecting portion 52 is located outside the first housing wall 23 and connected to the first housing wall 23. The first protrusion 51 protrudes from the surface of the connecting portion 52 facing away from the first housing wall 23. The first sealing member 50 has a first recessed portion 53 at a position corresponding to the first protrusion 51. The first recessed portion 53 is recessed relative to the surface of the connecting portion 52 facing the first housing wall 23.

[0383] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A battery cell, comprising: The electrode assembly comprises a main body and a first electrode tab, wherein the first electrode tab extends from one end of the main body along a first direction; The shell has a accommodating cavity, the electrode assembly is arranged in the accommodating cavity, the shell is provided with a first through hole and a second through hole, the part of the accommodating cavity located on the side of the first electrode ear is connected to the first through hole, the part of the accommodating cavity located on the side of the main body away from the first electrode ear is connected to the second through hole, the first through hole is used to inject electrolyte, and in the axial direction of the first through hole, the first electrode ear and the main body do not overlap with the first through hole.

2. The battery cell according to claim 1, wherein: The housing comprises a first shell wall and a second shell wall which are arranged opposite to each other along a second direction, the main body is located between the first shell wall and the second shell wall, and the second direction is parallel to the thickness direction of the battery cell and perpendicular to the first direction; The first shell wall is a flat wall, and the first through hole is arranged in the first shell wall.

3. The battery cell according to claim 2, wherein: The minimum aperture of the first through hole is D1, the dimension of the first shell wall along the third direction is W, and the third direction is perpendicular to the first direction and the second direction; 0.02≤D1 / W≤0.

2.

4. The battery cell according to claim 3, wherein: 2mm≤D1≤10mm. 5 . The battery cell according to claim 1 , further comprising a first sealing member connected to the housing and used to seal the first through hole.

6. The battery cell according to claim 5, wherein: The first sealing member includes a first protrusion and a connecting portion arranged around the first protrusion, the connecting portion is located outside the housing and connected to the housing, and the first protrusion protrudes from a surface of the connecting portion away from the housing.

7. The battery cell according to claim 6, wherein: In the axial direction of the first through hole, a dimension H2 of the first protrusion protruding from the outer surface of the housing satisfies: 0.5 mm ≤ H2 ≤ 2 mm.

8. The battery cell according to claim 6 or 7, wherein: The first sealing member is provided with a first recessed portion at a position corresponding to the first protruding portion, and the first recessed portion is recessed relative to a surface of the connecting portion facing the housing. 9 . The battery cell according to claim 8 , further comprising a second sealing member, a portion of the second sealing member being inserted into the first through hole, and another portion of the second sealing member being received in the first recess.

10. The battery cell according to any one of claims 5 to 9, wherein: The outer side of the shell is provided with a shell recess; In a second direction, the first sealing member is located at a side of the housing away from the housing recess, and the second direction is perpendicular to the first direction.

11. The battery cell according to any one of claims 5 to 10, wherein: The first sealing member is welded to the housing to form a welding portion.

12. The battery cell according to claim 11, wherein: The shell is provided with a weak portion, and the minimum distance between the welding portion and the weak portion is greater than or equal to 1 mm.

13. The battery cell according to claim 11 or 12, wherein: The welding portion is annular, the outer diameter of the welding portion is D2, the minimum aperture of the first through hole is D1, and 1.6≤D2 / D1≤2.

5.

14. The battery cell according to any one of claims 11 to 13, wherein: The area of ​​the welding portion is S1, the area of ​​the minimum cross section of the first through hole perpendicular to its own axial direction is S2, and 1.5≤S1 / S2≤5.

15. The battery cell according to any one of claims 5 to 14, wherein: The housing is provided with a second recess, and the first through hole extends inwardly from the bottom surface of the second recess; At least a portion of the first seal is configured to be received in the second recess. 16 . The battery cell according to claim 1 , further comprising a second sealing member, a portion of which is inserted into the first through hole.

17. The battery cell according to any one of claims 1 to 16, wherein: The housing comprises a first shell wall, the first shell wall comprises a wall body and a first convex wall, at least a portion of the first convex wall protrudes from a surface of the wall body facing the main body and is located at one side of the main body along the first direction; The first convex wall includes a first wall body for defining the first through hole.

18. The battery cell according to claim 17, wherein: The dimension of the first wall body along the second direction is H1, the minimum aperture of the first through hole is D1, 0.2≤H1 / D1≤1; the second direction is parallel to the thickness direction of the wall body. 19 . The battery cell according to claim 17 , further comprising a second sealing member, at least a portion of which is inserted into the first through hole and detachably connected to the first convex wall.

20. The battery cell according to claim 19, wherein: The second sealing member is interference-fitted with the first through hole.

21. The battery cell according to claim 19 or 20, wherein: The second sealing member has a large end and a small end which are arranged opposite to each other in the axial direction of the first through hole, and the small end is located inside the large end; The ratio of the diameter of the small end to the minimum aperture of the first through hole is 0.95-1.05, and the diameter of the large end is greater than the maximum aperture of the first through hole.

22. The battery cell according to any one of claims 19 to 21, wherein: An annular third recess is disposed on the outer periphery of the second sealing member, and at least a portion of the first wall is accommodated in the third recess.

23. The battery cell according to any one of claims 19 to 22, wherein: The first convex wall further includes a second wall body, the second wall body is arranged around the first wall body and connects the wall body and the first wall body, the second wall body protrudes inwardly from the wall body and is used to define a second recessed portion, the second recessed portion is recessed from the outer surface of the wall body, and the first through hole extends inwardly from the bottom surface of the second recessed portion; At least a portion of the second seal is received in the second recess.

24. The battery cell according to claim 23, wherein: The second wall body has a step surface, and in the axial direction of the first through hole, the step surface is closer to the outer surface of the wall body than the bottom surface of the second recessed portion; The projection of the step surface along the axial direction of the first through hole surrounds the projection of the bottom surface of the second recess along the axial direction of the first through hole; The battery cell further includes a first sealing member, at least a portion of which is received in the second recess and abuts against the step surface.

25. The battery cell according to any one of claims 1 to 24, further comprising a bracket, wherein the bracket is accommodated in the housing; The bracket is provided with a drainage recess connected to the first through hole, and the drainage recess is connected to the space between the main body and the bracket; In the axial direction of the first through hole, the first through hole is opposite to the bottom wall of the drainage recess.

26. The battery cell according to claim 25, wherein: The housing comprises a first shell wall, the first shell wall comprises a wall body and a first convex wall, at least a portion of the first convex wall protrudes from a surface of the wall body facing the main body and is located on one side of the main body along the first direction; the first convex wall comprises a first wall body for defining the first through hole; At least a portion of the first wall is accommodated in the drainage recess and is spaced apart from the bottom wall of the drainage recess.

27. The battery cell according to any one of claims 1 to 26, wherein: The minimum aperture of the second through hole is smaller than or equal to the minimum aperture of the first through hole.

28. The battery cell according to any one of claims 1 to 27, wherein: The second through hole is used for injecting electrolyte.

29. The battery cell according to any one of claims 1 to 28, wherein: The housing comprises a shell and a cover plate, the shell has an opening, and the cover plate covers the opening; The first through hole and the second through hole are disposed on the cover plate.

30. The battery cell according to any one of claims 1 to 29, wherein: The size of the shell along the first direction is L1, the size of the shell along the second direction is L2, and the size of the shell along the third direction is L3, and the first direction, the second direction and the third direction are perpendicular to each other; 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

31. A battery comprising a plurality of battery cells according to any one of claims 1 to 30.

32. An electrical device comprising the battery according to claim 31.

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