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 an outer casing. 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 outer casing comprises a housing cavity, and the electrode assembly is installed in the housing cavity. The outer casing is provided with a first communication hole and a second communication hole, the portion of the housing cavity located on one side of the first tab communicating with the first communication hole, and the portion of the housing cavity located on the side of the main body away from the first tab communicating with the second communication hole, the first communication hole being used for injecting an electrolyte. In the axial direction of the first communication hole, neither the first tab nor the main body overlaps with the first communication hole. This application can improve the cycle performance of the battery cell.

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application 202311458303.3, filed on 3 November 2023, titled "Battery Cell, Battery and Electrical Device," the entirety of which is incorporated herein by reference.

[0002] This application relates to the field of batteries, and more particularly to battery cells, batteries, and electrical devices. [Background technology]

[0003] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric scooters, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools.

[0004] In the development of battery technology, improving the cycle performance of battery cells is one of the research directions for battery technology. [Overview of the project]

[0005] This application provides a battery cell, a battery, and an electrical device that can improve the cycle performance of the battery cell.

[0006] In a first aspect, the present application provides a battery cell including an electrode assembly and an outer casing. 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 outer casing comprises a housing cavity, and the electrode assembly is installed in the housing cavity. The outer casing is provided with a first communication hole and a second communication hole, the portion of the housing cavity located on one side of the first tab communicating with the first communication hole, and the portion of the housing cavity located on the side of the main body away from the first tab communicating with the second communication hole, the first communication hole being used for injecting the electrolyte. In the axial direction of the first communication hole, neither the first tab nor the main body overlaps with the first communication hole.

[0007] During the production process of the battery cell, the electrolyte can be injected into the housing cavity through the first communication hole. During the electrolyte injection process, the gas in the housing cavity can be discharged through the second communication hole, thereby injecting the electrolyte into the battery cell under normal pressure and reducing the electrolyte injection resistance, eliminating the conventional vacuum process and thereby improving efficiency. The first and second communication holes communicate with spaces located on both sides along the first direction of the main body, respectively, thereby allowing the electrolyte to sufficiently permeate the main body during the flow process, improving the electrolyte permeation effect on the electrode assembly and improving the battery cell's cycle performance. When the electrolyte passes through the first communication hole, the direction of electrolyte flow is generally parallel to the axial direction of the first communication hole, and the embodiment of this application can reduce the risk of the electrolyte directly impacting the main body and the first tab after it flows out from the first communication hole, thereby reducing the impact force on the first tab and the main body, reducing deformation of the first tab and the main body, and improving the reliability of the battery cell.

[0008] In some embodiments, the outer casing includes a first casing wall and a second casing wall installed opposite each other along a second direction, the main body being located between the first and second casing walls, the second direction being parallel to the thickness direction of the battery cell and perpendicular to the first direction. The first casing wall is a flat wall, and the first communication hole is installed in the first casing wall. The first casing wall is located on the side along the thickness direction of the electrode assembly, is relatively flat, and has a relatively large area, making it easy to install the first communication hole.

[0009] In some embodiments, the minimum diameter of the first communication hole is D1, the dimension of the first casing wall along the third direction is W, the third direction is perpendicular to the first and second directions, and 0.02 ≤ D1 / W ≤ 0.2.

[0010] By limiting D1 / W to 0.02 or higher, the electrolyte injection efficiency is improved, and the uniformity of electrolyte infiltration into the electrode assembly is enhanced. By limiting D1 / W to 0.2 or lower, the strength loss at the first communication hole in the first casing wall is reduced, thereby reducing the risk of the first casing wall cracking when the battery cell is subjected to external impact, and improving reliability.

[0011] In some embodiments, setting D1 to 2 mm ≤ 10 mm improves the electrolyte injection efficiency, reduces the strength loss of the first casing wall, and lowers the requirements for the injection equipment.

[0012] In some embodiments, the battery cell further includes a first sealing member, which is connected to an outer casing and used to seal the first communication hole in order to reduce the risk of the housing cavity communicating with the external space of the battery cell through the first communication hole.

[0013] In some embodiments, the first sealing member includes a first protrusion and a connecting portion positioned around the first protrusion, the connecting portion being located outside the outer casing and connected to the outer casing, and the first protrusion protruding from the surface of the connecting portion away from the outer casing.

[0014] The first protrusion can act as a reinforcing rib, thereby improving the strength of the outer casing at the first communication hole, reducing the risk of the outer casing cracking around the first communication hole when the battery cell is subjected to external impact, and improving the reliability of the battery cell.

[0015] In some embodiments, in the axial direction of the first communication hole, the dimension H2 by which the first protrusion protrudes from the outer surface of the outer casing satisfies 0.5mm≦H2≦2mm. By limiting H2 to 0.5mm or more, the strength of the first sealing member is improved, the strength of the outer casing is reinforced, the risk of cracking of the outer casing is reduced, and the reliability of the battery cell is enhanced. By limiting H2 to 2mm or less, the extra space occupied by the first sealing member in the axial direction of the first communication hole is reduced, and the loss of the energy density of the battery cell is decreased.

[0016] In some embodiments, the first sealing member is provided with a first recess at a position corresponding to the first protrusion, and the first recess is recessed relative to the surface of the connection portion facing the outer casing. By providing the first recess, the weight of the first sealing member can be reduced, and the energy density of the battery cell can be improved.

[0017] In some embodiments, the battery cell further includes a second sealing member, a part of the second sealing member is inserted into the first communication hole, and another part of the second sealing member is accommodated in the first recess.

[0018] The second sealing member and the first sealing member can perform a double sealing function, thereby improving sealing performance, reducing the risk of electrolyte leakage, and enhancing the reliability of the battery cell. The first recess can not only avoid interference with the second sealing member, but also positionally restrict and fix the second sealing member, reducing the risk of the second sealing member loosening when the battery cell is subjected to an external impact, and improving the sealing performance and reliability of the battery cell.

[0019] In some embodiments, an outer casing recess is provided on the outer side of the outer casing. In the second direction, the first sealing member is located on the side of the outer casing facing away from the outer casing recess, and the second direction is perpendicular to the first direction.

[0020] By providing the recessed portion in the outer casing, the volume of the battery cell can be reduced, and the energy density can be improved. When a plurality of battery cells are arranged along the second direction, the recessed portion in the outer casing of one battery cell can avoid the first sealing member of another battery cell, thereby improving the space utilization rate and increasing the energy density of the battery.

[0021] In some embodiments, the first sealing member is welded to the outer casing to form a welded portion. Welding can improve the connection strength between the first sealing member and the outer casing, and can also improve the sealing performance.

[0022] In some embodiments, the outer casing is provided with a fragile portion, and the minimum distance between the welded portion and the fragile portion is 1 mm or more, which reduces the influence of the heat-affected zone on the fragile portion, reduces the thermal stress that the fragile portion receives after welding, lowers the risk of fracture failure of the fragile portion, and improves the reliability of the battery cell.

[0023] In some embodiments, the welded portion is annular, the outer diameter of the welded portion is D2, the minimum pore diameter of the first communication hole is D1, and 1.6≦D2 / D1≦2.5.

[0024] By limiting D2 / D1 to 1.6 or more, the strength of the welded portion is improved, the structural strength around the first communication hole of the battery cell is enhanced, and the risk of the outer casing cracking around the first communication hole is reduced. By limiting D2 / D1 to 2.5 or less, the heat-affected zone caused by welding is restricted, and the risk of other structures of the battery cell failing under the action of thermal stress is reduced.

[0025] In some embodiments, the area of the welded portion is S1, the area of the minimum cross section of the first communication hole perpendicular to its own axial direction is S2, and 1.5≦S1 / S2≦5.

[0026] By limiting S1 / S2 to 1.5 or greater, the connection strength between the first sealing member and the outer casing is improved, the structural strength around the first communication hole of the battery cell is improved, and the risk of cracking around the first communication hole of the outer casing is reduced. In the embodiment of the present invention, by limiting S1 / S2 to 5 or less, the heat-affected zone due to welding is limited, and the risk of other structures of the battery cell failing under the action of thermal stress is reduced.

[0027] In some embodiments, the outer casing is provided with a second recess, and the first communication hole extends inward from the bottom surface of the second recess. At least a portion of the first sealing member is installed to be housed in the second recess.

[0028] When assembling the first sealing member, the second recess can serve a positioning role, thereby simplifying the assembly process of the first sealing member. By providing the second recess, the space that the first sealing member occupies extra in the axial direction of the first communication hole can be further reduced, thereby improving space utilization.

[0029] In some embodiments, the battery cell further includes a second sealing member, a portion of which is inserted into the first communication hole.

[0030] In some embodiments, the exterior casing includes a first casing wall. The first casing wall includes a wall body and a first convex wall, at least a portion of which protrudes from the surface of the wall body facing the main body and is located on the side of the main body along a first direction. The first convex wall includes a first wall body for defining a first communication hole.

[0031] By installing a first protruding wall that extends inward, the depth of the first communication hole can be increased, improving the structural strength of the first casing wall around the first communication hole and reducing deformation of the first casing wall.

[0032] In some embodiments, the dimension of the first wall along the second direction is H1, the minimum diameter of the first communication hole is D1, and 0.2 ≤ H1 / D1 ≤ 1. The second direction is parallel to the thickness direction of the wall body.

[0033] By limiting H1 / D1 to 0.2 or greater, the structural strength and stability of the first wall are improved, and the risk of deformation and cracking of the first wall is reduced. By limiting H1 / D1 to 1 or less, the space occupied by the first wall relative to the internal space of the outer casing is reduced, the resistance of electrolyte flow in the outer casing is reduced, and the injection efficiency is improved.

[0034] In some embodiments, the battery cell further includes a second sealing member, at least a portion of which is inserted into a first communication hole and removably connected to a first convex wall.

[0035] The second sealing member can be used to seal the first communication hole and improve the sealing performance of the battery cell. The second sealing member can be attached and detached multiple times during the production process of the battery cell, facilitating multiple processing steps on the battery cell through the first communication hole. The first convex wall has a relatively large dimension in the second direction, and connecting the second sealing member to the first convex wall can improve the connection strength.

[0036] In some embodiments, the second sealing member is an interference fit with the first communication hole. The interference fit method not only effectively seals the first communication hole but also allows for easy attachment and detachment of the second sealing member.

[0037] In some embodiments, the second sealing member comprises a large end and a small end positioned opposite each other along the axial direction of the first communication hole, with the small end located inside the large end. The ratio of the diameter D4 of the small end to the minimum hole diameter D1 of the first communication hole is 0.95 to 1.05, and the diameter of the large end is greater than the maximum hole diameter of the first communication hole.

[0038] By limiting D4 / D1 to 0.95~1.05, the second sealing member can be easily inserted into the first communication hole, the large end of the second sealing member has a relatively large dimension, reducing the risk of the second sealing member falling into the housing cavity through the first communication hole, and effectively covering the first communication hole to improve sealing performance.

[0039] In some embodiments, an annular third recess is provided on the outer circumference of the second sealing member, and at least a portion of the first wall is housed in the third recess.

[0040] The first wall can be inserted into the third recess and form a rivet joint structure with the second sealing member, thereby restricting the movement of the second sealing member in the second direction, improving the stability of the second sealing member, and improving the sealing performance.

[0041] In some embodiments, the first convex wall further includes a second wall body, which is installed surrounding the first wall body and connecting the wall body and the first wall body, the second wall body protruding inward from the wall body and used to define a second recess, the second recess being recessed from the outer surface of the wall body, and the first communication hole extending inward from the bottom surface of the second recess. At least a portion of the second sealing member is housed in the second recess.

[0042] The second wall has a structure that protrudes on the inside and recesses on the outside, and this structure can improve the strength of the first casing wall and reduce the risk of deformation and cracking of the first casing wall. The second recess further accommodates a part of the second sealing member, thereby reducing the space that the second sealing member occupies extra in the axial direction of the first communication hole, and thereby improving the space utilization rate.

[0043] In some embodiments, the second wall has a stepped surface, and in the axial direction of the first communication hole, the stepped surface is closer to the outer surface of the wall body than to the bottom surface of the second recess. The projection of the stepped surface along the axial direction of the first communication hole surrounds the projection of the bottom surface of the second recess along the axial direction of the first communication hole. The battery cell further includes a first sealing member, at least a portion of which is housed in the second recess and in contact with the stepped surface.

[0044] By installing a stair surface, the overall structural strength of the second wall can be improved. The stair surface and the bottom surface of the second recess restrict the positions of the first and second sealing members, respectively, and reduce the risk of the second sealing member spreading between the first sealing member and the stair surface under pressure. This also helps to some extent to prevent the second sealing member from interfering with the connection between the first sealing member and the second wall, thereby improving reliability.

[0045] In some embodiments, the battery cell further includes a support, which is housed within an outer casing. The support is provided with a drainage recess that communicates with a first communication hole, and the drainage recess communicates with a space located between the main body and the support. In the axial direction of the first communication hole, the first communication hole faces the bottom wall of the drainage recess.

[0046] The bottom wall of the drain recess absorbs the impact of the electrolyte and guides the electrolyte to flow within the drain recess, thereby reducing the impact of the electrolyte on the main body and reducing deformation of the separator in the main body. The support can also support the outer casing to reduce the risk of deformation caused by pressure from external equipment during the electrolyte injection process, thereby improving the reliability of the battery cell.

[0047] In some embodiments, the exterior casing includes a first casing wall, the first casing wall includes a wall body and a first convex wall, at least a portion of which protrudes from the surface of the wall body facing the main body and is located on the side of the main body along a first direction, and the first convex wall includes a first wall body for defining a first communication hole. At least a portion of the first wall body is housed in a drain recess and is installed at a distance from the bottom wall of the drain recess.

[0048] The drain recess can also avoid the first wall to provide more space to the first wall and increase the depth of the first communication hole.

[0049] In some embodiments, the minimum diameter of the second communication hole is smaller than the minimum diameter of the first communication hole. During the liquid injection process, the second communication hole is used to evacuate and stabilize the pressure, and because gas is more fluid than liquid, the second communication hole may have a relatively small diameter to reduce the loss of strength of the outer casing.

[0050] In some embodiments, the minimum diameter of the second communication hole is equal to the minimum diameter of the first communication hole. The first and second communication holes are interchangeable, and the external equipment may inject the electrolyte into the containment cavity through the first communication hole or through the second communication hole.

[0051] In some embodiments, the second communication port is used for injecting electrolytes. The first and second communication ports can be used simultaneously for electrolyte injection to improve electrolyte injection efficiency.

[0052] In some embodiments, the outer casing includes a casing and a cover plate, the casing having an opening, and the cover plate covering the opening. A first and second communication hole are provided in the cover plate, thereby simplifying the molding process of the outer casing.

[0053] In some embodiments, the dimension of the outer casing along the first direction is L1, the dimension along the second direction is L2, and the dimension along the third direction is L3, and the first, second, and third directions are perpendicular to each other. 1.2 ≤ L1 / L3 ≤ 18 and 1.2 ≤ L3 / L2 ≤ 15.

[0054] Assuming a constant volume of the battery cell, limiting L1 / L3 to 1.2-18 and L3 / L2 to 1.2-15 balances the space utilization rate in the first direction of the battery cell and the current passability of the first tab, reduces the temperature rise of the battery cell, reduces the risk of deformation when the battery cell is subjected to external shock, and improves the reliability and cycle performance of the battery cell.

[0055] In a second aspect, the present application provides a battery comprising a plurality of battery cells provided in any one embodiment of the first aspect.

[0056] In a third aspect, the present application provides an electrical device including a battery provided by any one embodiment of the second aspect. [Brief explanation of the drawing]

[0057] The features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the drawings. [Figure 1] This is a schematic diagram of the structure of a vehicle provided by some embodiments of the present application. [Figure 2] This is a schematic diagram of the disassembled battery provided by some embodiments of the present application. [Figure 3] This is a schematic diagram of the structure of a battery provided by some other embodiments of the present application. [Figure 4] This is a schematic diagram of the structure of a battery cell provided by some embodiments of the present application. [Figure 5] Figure 4 is a schematic cross-sectional view of the battery cell along the AA direction. [Figure 6]This is a schematic diagram of the structure of the electrode assembly and cover plate assembly of a battery cell provided by some embodiments of the present application. [Figure 7] This is a schematic local cross-sectional view of a first communication hole in a battery cell provided by some embodiments of the present application. [Figure 8] Figure 7 is a schematic diagram of the first casing wall. [Figure 9] Figure 7 is a schematic plan view of the first sealing member. [Figure 10] This is a schematic cross-sectional view of a second sealing member of a battery cell provided by some embodiments of the present application. [Figure 11] This is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some other embodiments of the present application. [Figure 12] This is a schematic cross-sectional view of a second sealing member of a battery cell provided in some other embodiments of the present application. [Figure 13] This is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some further embodiments of the present application. [Figure 14] This is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some further embodiments of the present application. [Figure 15] Figure 14 is a schematic diagram of the first casing wall. [Figure 16] This is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some other embodiments of the present application. [Figure 17] This is a schematic diagram of the structure of a support provided by some embodiments of the present application. [Figure 18] Figure 17 is a schematic diagram of the insulating support from a different angle. [Figure 19] Figure 18 is a schematic cross-sectional view along the BB direction. [Explanation of Symbols]

[0058] 1. Vehicle, 2. Battery, 3. Controller, 4. Motor, 5. Case, 5a. First case section, 5b. Second case section, 5c. Housing space, 6. Battery cell, 7. Bus component, 10. Electrode assembly, 11. Main body, 12. First tab, 13. Second tab, 20, outer casing, 20a, first communication hole, 20b, second communication hole, 20c, housing cavity, 21, casing, 22, cover plate, 23, first casing wall, 231, weak part, 232, second recess, 232a, bottom surface, 232b, stepped surface, 233, wall body, 234, first convex wall, 234a, first wall body, 234b, second wall body, 24, second casing wall, 25, outer casing recess, 30, first electrode lead member, 31, adapter, 32, electrode terminal, 33, terminal board, 40. Second electrode extraction 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, Welded parts, 80, support, 80a, drain recess, 80b, bottom wall, 80c, liquid injection opening, 80d, housing recess, 81, support block, 82, insulating substrate, 83, first position limiting plate, 84, second position limiting plate, 85, third position limiting plate, X is the first direction, Y is the second direction, and Z is the third direction. [Modes for carrying out the invention]

[0059] Hereinafter, embodiments specifically disclosing the sodium-ion battery cell, battery, and electrical device according to the present application will be described in detail, with reference to the drawings as appropriate. However, unnecessary detailed explanations may be omitted. For example, detailed explanations of already well-known matters and repeated explanations of substantially the same structures may be omitted. This is to avoid making the following explanation unnecessarily long and to facilitate understanding by those skilled in the art. Furthermore, the drawings and the following explanation are provided so that the present application can be fully understood by those skilled in the art and are not intended to limit the essence of what is stated in the claims.

[0060] The “range” disclosed herein is limited in the form of a lower limit and an upper limit, and a given range is limited by selecting one lower limit and one upper limit, and the boundaries of a special range are limited by the selected lower and upper limits. The range thus limited may include or exclude the values ​​at both ends, and may be in any combination, that is, any lower limit may be combined with any upper limit to form a single range. For example, if the ranges 60-120 and 80-110 are given for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also expected. Similarly, if the minimum range values ​​1 and 2 are given, and the maximum range values ​​3, 4 and 5 are given, the ranges 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5 are all expected. In this application, unless otherwise stated, the numerical range “a-b” represents an abbreviated expression for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between "0 to 5" have already been listed in this specification, and "0 to 5" is simply an abbreviation for combinations of those numbers. Also, when it is stated that a parameter is an integer ≥ 2, this is equivalent to disclosing that the parameter is an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0061] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0062] Unless otherwise defined, all technical and scientific terms used in this Application have the same meaning as those generally understood by those skilled in the art relating to the Application. The terms used in the Specification of this Application are solely for the purpose of describing specific embodiments and are not intended to limit this Application. The terms “including” and “having,” and any variations thereof, in the Specification, Claims, and Brief Description of the Drawings, are intended to cover non-exclusive inclusion. Terms such as “first,” “second,” etc., in the Specification, Claims, or Drawings are used to distinguish different subjects and are not used to indicate a particular order or priority.

[0063] In this description, unless otherwise specified or limited, the terms “attachment,” “connection,” “joining,” and “attaching” should be understood broadly to mean, for example, a fixed connection, a removable connection, an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. A person skilled in the art may understand the specific meaning of these terms in this application depending on the specific circumstances.

[0064] In the embodiments of this application, the same drawing symbols represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. The dimensions such as thickness, length, and width of various components in the embodiments of this application shown in the attached drawings, as well as the overall thickness, length, and width of the integrated device, are merely illustrative and should not be understood as constituting any limitation to this application.

[0065] Unless otherwise specified, the term "or" in this application is 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 by any of the following: 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).

[0066] In this application, the terms "multiple" and "multiple types" mean two or more types.

[0067] Unless otherwise specified, the values ​​of each parameter referred to herein can be measured using various test methods commonly used in the art, for example, according to the test methods shown in the embodiments of this application. Unless otherwise specified, the test temperature for each parameter is 25°C.

[0068] In the embodiments of the present invention, the battery cell may be a secondary battery, which refers to a battery cell that can be repeatedly used by activating the active material by charging after the battery cell has been discharged.

[0069] A battery cell generally includes an electrode assembly, which includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) repeatedly insert into and remove from the positive and negative electrodes. Exemplarily, the electrode assembly further includes a separator placed between the positive and negative electrodes, which serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0070] 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-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, and others.

[0071] The battery cell may be a prismatic battery cell or a battery cell of another shape. The prismatic battery cell includes a rectangular parallelepiped, a blade-shaped battery cell, or a polygonal prismatic battery. The polygonal prismatic battery may be, for example, a hexagonal prismatic battery, and the battery cell of another shape may be a cylindrical battery.

[0072] The battery cell may be a rigid-casing battery cell, a soft-pack battery cell, or another type of battery cell.

[0073] The batteries referred to in the embodiments of this application refer to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0074] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a single battery module.

[0075] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, with the battery cells or battery modules housed in the case.

[0076] In some embodiments, the case may be part of the vehicle's chassis structure. For example, the case portion may be at least part of the vehicle's chassis, or the case portion may be at least part of the vehicle's cross members and side members.

[0077] In some embodiments, the battery may be an energy storage device. The energy storage device includes energy storage containers, energy storage electrical cabinets, and the like.

[0078] During the production process of battery cells, it is necessary to inject an electrolyte into the inside of the battery cell. Typically, the electrolyte injection process involves first evacuating the inside of the battery cell and then using the pressure difference to inject the electrolyte into the battery cell. Long vacuuming times, slow electrolyte injection rates, and low electrolyte penetration effect on the electrode assembly affect the production efficiency and cycle performance of the battery cells.

[0079] In view of these, the embodiment of the present application provides a technical solution that allows the electrolyte to be injected into the battery cell under normal pressure by providing a first communication hole and a second communication hole in the outer casing of the battery cell, thereby reducing the electrolyte injection resistance, saving time, and improving the electrolyte penetration effect on the electrode assembly and the cycle performance of the battery cell.

[0080] The technical invention described in the embodiments of this application is applicable to batteries and electrical devices using batteries.

[0081] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, aerospace vehicles, electric toys, and power tools. Vehicles may be fuel-powered vehicles, natural gas vehicles, or new energy vehicles, and new energy vehicles may include pure electric vehicles, hybrid vehicles, or range-extender vehicles. Aerospace vehicles may include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys, and electric airplane toys. Power tools include metal cutting power tools such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, as well as grinding power tools, assembly power tools, and railway power tools. The embodiments of this application do not impose any special limitations on the above-mentioned electrical devices.

[0082] For the sake of explanation, the following examples will be described using the case where the electrical device is a vehicle.

[0083] Figure 1 is a schematic diagram of the structure of a vehicle provided by some embodiments of the present application.

[0084] As shown in Figure 1, a battery 2 is installed inside the vehicle 1, and the battery 2 may be installed in the bottom, front, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 can function as the operating power source for the vehicle 1.

[0085] Vehicle 1 may further include a controller 3 and a motor 4, the controller 3 controlling a battery 2 to supply power to the motor 4, and is used, for example, to meet the operating power needs of vehicle 1 during starting, navigation, and driving.

[0086] In some embodiments of the present invention, the battery 2 can be used not only as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, providing driving force to the vehicle 1 by completely or partially replacing fuel or natural gas.

[0087] Figure 2 is a schematic diagram of an exploded battery provided by some embodiments of the present application.

[0088] As shown in Figure 2, the battery 2 includes a case 5 and a battery cell 6 (not shown), the battery cell 6 being housed within the case 5.

[0089] Case 5 is used to house the battery cell 6, and case 5 may have various structures. In some embodiments, case 5 may include a first case portion 5a and a second case portion 5b, the first case portion 5a and the second case portion 5b covering each other, and the first case portion 5a and the second case portion 5b jointly defining a housing space 5c for housing the battery cell 6. The second case portion 5b may be a hollow structure with one end open, and the first case portion 5a is a plate-like structure, the first case portion 5a covering the open side of the second case portion 5b to form case 5 having the housing space 5c, and both the first case portion 5a and the second case portion 5b may be hollow structures with one side open, the open side of the first case portion 5a covering the open side of the second case portion 5b to form case 5 having the housing space 5c. The first case portion 5a and the second case portion 5b may have various shapes, such as a cylinder or a rectangular parallelepiped.

[0090] To improve the airtightness after the first case portion 5a and the second case portion 5b are connected, a sealing member such as a sealant or a sealing ring may be installed between the first case portion 5a and the second case portion 5b.

[0091] Assuming that the first case portion 5a covers the top of the second case portion 5b, the first case portion 5a may be called the upper case cover, and the second case portion 5b may be called the lower case.

[0092] In battery 2, there may be one battery cell 6 or multiple battery cells 6. If there are multiple battery cells 6, the multiple battery cells 6 may be connected in series, in parallel, or in series-parallel, where series-parallel connection means that the multiple battery cells 6 have both series and parallel connections. The multiple battery cells 6 may be directly connected in series, in parallel, or in series-parallel, and the entire assembly composed of multiple battery cells 6 is housed in case 5. Of course, the multiple battery cells 6 may first be connected in series, in parallel, or in series-parallel to form a battery module, and then the multiple battery modules may be connected in series, in parallel, or in series-parallel to form an entire assembly, and then housed in case 5.

[0093] Figure 3 is a schematic diagram of the structure of a battery provided in some other embodiments of the present application.

[0094] As shown in Figure 3, in some embodiments, the battery 2 includes a plurality of battery cells 6 and a plurality of bus members 7, and the plurality of bus members 7 can connect the plurality of battery cells 6 in series, in parallel, or in series-parallel.

[0095] Figure 4 is a schematic diagram of the structure of a battery cell provided in some embodiments of the present application, Figure 5 is a schematic cross-sectional view of the battery cell shown in Figure 4 along the AA direction, and Figure 6 is a schematic diagram of the structure of the electrode assembly and cover plate assembly of the battery cell provided in some embodiments of the present application.

[0096] Referring to Figures 4 to 6, an embodiment of the present application provides a battery cell 6 including an electrode assembly 10 and an outer casing 20, the electrode assembly 10 being installed inside the outer casing 20.

[0097] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 6, active ions (e.g., lithium ions) repeatedly insert into and remove from between the positive and negative electrodes. Selectively, the electrode assembly 10 further includes a separator placed between the positive and negative electrodes, which can reduce the risk of short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0098] In some embodiments, the positive electrode may be a positive electrode piece that includes a positive electrode current collector and a positive electrode active material layer placed on at least one surface of the positive electrode current collector.

[0099] For example, the positive electrode current collector has two opposing surfaces in its thickness direction, and the positive electrode active material layer is placed on one or both of the two opposing surfaces of the positive electrode current collector.

[0100] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as metal foil, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, titanium, and aluminum or stainless steel surface-treated with silver can 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 (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer material base (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0101] As an example, the positive electrode active material layer may include a positive electrode active material that can contain at least one of the materials of lithium-containing phosphates, lithium transition metal oxides, and respective modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as the positive electrode active material layer of a battery may also be used. These positive electrode active material layers may be used alone singly, or in combination of two or more. Among them, examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (for example, LiFePO4 (may be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (for example, LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide include lithium cobalt oxide (for example, LiCoO2), lithium nickel oxide (for example, LiNiO2), lithium manganese oxide (for example, LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as), LiNi 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as), LiNi 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as), LiNi 0.6 Co 0.2 Mn 0.2 O2(NCM 622 (may be abbreviated as), LiNi 0.8 Co 0.1 Mn 0.1 O2(NCM 811 (may be abbreviated as)), lithium nickel cobalt aluminum oxide (for example, LiNi 0.80 Co 0.15 Al 0.05It may contain, but is not limited to, at least one of O2 and its modified compounds.

[0102] In some embodiments, the positive electrode can be made of foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. When foamed metal is used as the positive electrode, a positive electrode active material layer does not need to be placed on the surface of the foamed metal, although it is certainly possible to place a positive electrode active material layer. As an example, lithium metal and / or lithium-rich materials such as lithium source material, potassium metal, or sodium metal may be further filled and / or deposited within the foamed metal.

[0103] In some embodiments, the negative electrode may be a negative electrode piece that includes a negative electrode current collector.

[0104] As an example, the negative electrode current collector can be a metal foil, foamed metal, 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 electrodes, carbon, nickel, or titanium can be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector is formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base (a base material such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0105] As an example, the negative electrode piece may include a negative electrode current collector and a negative electrode active material placed on at least one surface of the negative electrode current collector.

[0106] For example, the negative electrode current collector has two opposing surfaces in its thickness direction, and the negative electrode active material is placed on one or both of the two opposing surfaces of the negative electrode current collector.

[0107] As an example, the negative electrode active material can be a negative electrode active material for a battery cell 6 known in the art. For 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, and lithium titanate. The silicon-based material may be selected from at least one of elemental silicon, silicon oxygen 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 oxygen compounds, and tin alloys. However, the present application is not limited to these materials, and other conventional materials usable as negative electrode active materials for batteries may be used. These negative electrode active materials may be used individually or in combination of two or more.

[0108] 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.

[0109] In some embodiments, the separator includes a separator film. The present application does not impose any particular restrictions on the type of separator film, and any known porous separator film having good chemical and mechanical stability can be selected.

[0110] As an example, the main material of the separator film may be at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator film may be a single-layer film or a multi-layer composite film, and there are no particular restrictions. If the separator film is a multi-layer composite film, the materials of each layer may be the same or different, and there are no particular restrictions. The separator may be a single component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0111] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is placed between the positive and negative electrodes and serves to transport ions and separate the positive and negative electrodes.

[0112] The outer casing 20 has a hollow structure, and a housing space is formed inside for accommodating the electrode assembly 10 and the electrolyte. The shape of the outer casing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped outer casing may be selected.

[0113] The outer casing 20 may be made of various materials; for example, the outer casing 20 may be made of metal or plastic. Selectively, the outer casing 20 may be made of copper, iron, aluminum, steel, aluminum alloy, etc. Exemplarily, the outer casing 20 may be a steel casing, an aluminum casing, a plastic casing (e.g., polypropylene), a composite metal casing (e.g., a copper-aluminum composite outer casing), or an aluminum-plastic film, etc.

[0114] As an example, the exterior casing 20 includes a casing 21 and a cover plate 22, the casing 21 having an opening, and the cover plate 22 being used to cover the opening.

[0115] The casing 21 is a component that fits with the cover plate 22 to form an internal cavity for the battery cell 6, and the formed internal cavity can be used to house the electrode assembly 10, electrolyte, and other components.

[0116] The outer casing 21 and the cover plate 22 may be independent components. For example, an opening may be provided in the casing 21, and the cover plate 22 covers the opening to form the internal cavity of the battery cell 6.

[0117] The casing 21 may have various shapes and dimensions, such as a rectangular parallelepiped or a hexagonal prism. Specifically, the shape of the casing 21 may be determined according to the specific shape and dimensions of the electrode assembly 10. The casing 21 may be made of various materials, such as copper, iron, aluminum, stainless steel, or aluminum alloy.

[0118] The shape of the cover plate 22 may be adapted to the shape of the casing 21 in order to fit into the casing 21. The material of the cover plate 22 and the material of the casing 21 may be the same or different. Selectively, the cover plate 22 may be made of a material with a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), in which case the cover plate 22 will be less prone to deformation when subjected to pressure and impact, the battery cell 6 may have higher structural strength, and its reliability may also be improved.

[0119] The cover plate 22 may be connected to the casing 21 by welding, bonding, engagement, or other means.

[0120] Figure 7 is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some embodiments of the present application, Figure 8 is a schematic view of the first casing wall shown in Figure 7, and Figure 9 is a schematic top view of the first sealing member in Figure 7.

[0121] Referring also to Figures 4 to 9, some embodiments of the present application provide a battery cell 6 including an electrode assembly 10 and an outer casing 20, the outer casing 20 comprising a housing cavity 20c, and the electrode assembly 10 is installed in the housing cavity 20c. The electrode assembly 10 includes a main body 11 and a first tab 12, the first tab 12 extending from one end of the main body 11 along a first direction X. The outer casing 20 is provided with a first communication hole 20a and a second communication hole 20b, the portion of the housing cavity 20c located on the side of the main body 11 facing the first tab 12 communicating with the first communication 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 communicating with the second communication hole 20b, the first communication hole 20a being used for injecting the electrolyte.

[0122] The electrode assembly 10 is a component that undergoes an electrochemical reaction in the battery cell 6. The outer casing 20 may contain one or more electrode assemblies 10. The electrode assembly 10 may have a wound structure, a laminated structure, a wound-laminated composite structure, or other structures.

[0123] The shape of the electrode assembly 10 may be cylindrical, flattened, or polygonal prism-shaped, etc.

[0124] As an example, the electrode assembly 10 includes a first electrode piece, a second electrode piece, and a separator, wherein the polarity of the first electrode piece and the polarity of the second electrode piece are opposite, and the separator is used to insulate and isolate the first electrode piece and the second electrode piece.

[0125] The first pole piece includes a first current collector and a first active material layer coated on the surface of the first current collector, and the second pole piece 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 to which the first active material layer is coated, the portion of the second current collector to which the second active material layer is coated, the first active material layer and the second active material layer, and the first tab 12 includes the portion of the first current collector to which the first active material layer is not coated.

[0126] The first and second pole pieces are such that one is the positive pole piece and the other is the negative pole piece.

[0127] The first communication hole 20a may be one or multiple. The second communication hole 20b may be one or multiple.

[0128] The first communication hole 20a may be a circular hole, a square hole, an elliptical hole, or a communication hole of other shape. The second communication hole 20b may be a circular hole, a square hole, an elliptical hole, or a communication hole of other shape. The shape of the first communication hole 20a may be the same as or different from the shape of the second communication hole 20b.

[0129] The diameter of the first communication hole 20a may be larger than, smaller than, or equal to the diameter of the second communication hole 20b.

[0130] The axial direction of the first communication hole 20a may be parallel to the first direction X, or it may intersect the first direction X. For example, the axial direction of the first communication hole 20a may be perpendicular to the first direction X.

[0131] Exemplary, both ends of the housing cavity 20c along the first direction X communicate with the first communication hole 20a and the second communication hole 20b, respectively. Exemplary, the portion of the housing cavity 20c located on the side facing the first tab 12 of the main body 11 communicates with the first communication hole 20a.

[0132] In the embodiments of the present application, communication between the first communication hole 20a and the containment cavity 20c can mean that, if the first communication hole 20a is not sealed by another member, an external substance (e.g., fluid) can enter the containment cavity 20c through the first communication hole 20a, and similarly, a fluid in the containment cavity 20c can flow to the outside of the outer casing 20 through the first communication hole 20a. Communication between the second communication hole 20b and the containment cavity 20c can mean that, if the second communication hole 20b is not sealed by another member, an external substance (e.g., fluid) can enter the containment cavity 20c through the second communication hole 20b, and similarly, a fluid in the containment cavity 20c can flow to the outside of the outer casing 20 through the second communication hole 20b.

[0133] The first communication hole 20a may be used to inject the electrolyte during the production process of the battery cell 6, or it may be used in other processes during the production of the battery cell 6. For example, during the chemical conversion process of the battery cell 6, the first communication hole 20a can also be used to draw out gases generated inside the battery cell 6.

[0134] During the manufacturing process of the battery cell 6, the electrolyte can be injected into the housing cavity 20c through the first communication hole 20a. During the electrolyte injection process, the gas in the housing cavity 20c can be discharged through the second communication hole 20b, thereby injecting the electrolyte into the battery cell 6 under normal pressure and reducing the electrolyte injection resistance, eliminating the conventional vacuum process and thereby improving efficiency. The first communication hole 20a and the second communication hole 20b communicate with the spaces on both sides of the main body 11 along the first direction X, respectively, thereby allowing the electrolyte to sufficiently permeate the main body 11 during the flow process, improving the electrolyte permeation effect on the electrode assembly 10 and improving the cycle performance of the battery cell 6.

[0135] The end face of the main body 11 facing the first tab 12 is typically provided with a slit, and the electrolyte flows into the housing cavity 20c through the first communication hole 20a and then penetrates into the interior of the main body 11 along the slit, thereby improving the electrolyte's penetration effect into the electrode assembly 10.

[0136] In some embodiments, after the electrolyte injection process is completed, the first communication hole 20a and the second communication hole 20b can be sealed using a sealing member to isolate the containment cavity 20c from the space outside the outer casing 20.

[0137] In some embodiments, neither the first tab 12 nor the main body 11 overlaps with the first communication hole 20a in the axial direction of the first communication hole 20a.

[0138] The axial direction of the first communication hole 20a can refer to the direction parallel to the central axis of the first communication hole 20a.

[0139] In the axial direction of the first communication hole 20a, the first tab 12 not overlapping with the first communication hole 20a means that the projection of the first tab 12 along the axial direction does not overlap with the projection of the first communication hole 20a along the axial direction. In the axial direction of the first communication hole 20a, the main body 11 not overlapping with the first communication hole 20a means that the projection of the main body 11 along the axial direction does not overlap with the projection of the first communication hole 20a along the axial direction.

[0140] When the electrolyte passes through the first communication hole 20a, the flow direction of the electrolyte is generally parallel to the axial direction of the first communication hole 20a. The embodiment of the present application can reduce the risk of the electrolyte directly impacting the main body 11 and the first tab 12 after it has flowed out of the first communication hole 20a, thereby reducing the impact force on the first tab 12 and the main body 11, reducing deformation of the first tab 12 and the main body 11, and improving the reliability of the battery cell 6.

[0141] In some embodiments, when injecting the electrolyte, the first direction X can be made approximately parallel to the horizontal plane, in which case the electrolyte is injected into the containment cavity 20c through the first communication hole 20a, and the second communication hole 20b can serve to stabilize the air pressure. Embodiments of the present invention are easy to operate.

[0142] In some embodiments, when injecting the electrolyte, the first direction X can be at a constant angle with the horizontal plane; for example, the first direction X may be perpendicular to the horizontal plane. In this case, the first communication hole 20a is positioned lower, the electrolyte is injected through the first communication hole 20a, and the second communication hole 20b can serve to stabilize the air pressure. Due to the action of gravity, the electrolyte gradually enters the electrode assembly 10 from bottom to top, and combined with the siphon action of the slits between the electrode pieces of the electrode assembly 10, the infiltration effect of the electrolyte into the electrode assembly 10 can be improved.

[0143] In some embodiments, the main body 11 further includes a second tab 13, wherein the first tab 12 and the second tab 13 have opposite polarities. Exemplarily, the second tab 13 includes a portion of the second current collector that is not coated with the second active material layer.

[0144] The second tab 13 and the first tab 12 may extend from the same end of the main body 11 along the first direction X, or they may extend from both ends of the main body 11 along the first direction X, respectively.

[0145] In some embodiments, the first tab 12 and the second tab 13 extend from both ends of the main body 11 along the first direction X, respectively, to reduce the risk of short circuits caused by contact between the first tab 12 and the second tab 13.

[0146] The second communication hole 20b communicates with the space in the housing cavity 20c located on the side of the main body 11 facing the second tab 13.

[0147] In some embodiments, the dimension of the outer casing 20 along the first direction X is L1, the dimension of the outer casing 20 along the second direction Z is L2, and the dimension of the outer casing 20 along the third direction Y is L3, and the first direction X, the second direction Z, and the third direction Y are perpendicular to each other. 1.2 ≤ L1 / L3 ≤ 18 and 1.2 ≤ L3 / L2 ≤ 15.

[0148] 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.

[0149] For example, L1 may be the maximum dimension of the outer casing 20 along a first direction X, L2 may be the maximum dimension of the outer casing 20 along a second direction Z, and L3 may be the maximum dimension of the outer casing 20 along a third direction Y.

[0150] The first tab 12 is positioned at the end of the electrode assembly 10 along the first direction X, occupying extra space in the first direction X. The larger L1, the smaller the dimensional occupancy of the first tab 12 in the first direction X, and the higher the space utilization rate of the battery cell 6 in the first direction X. The larger L3, the larger the current passage area of ​​the first tab 12, improving the current passage capability of the first tab 12 and reducing heat generation.

[0151] The smaller L2 is, the shorter the path through which the electrode assembly 10 dissipates heat to the outside, resulting in a lower temperature rise of the battery cell 6 during charging and discharging. However, the smaller L2 is, the thinner the battery cell 6 becomes, making it more susceptible to deformation when subjected to external impacts during production, transportation, and use.

[0152] Assuming the volume of the battery cell 6 is constant, by limiting L1 / L3 to 1.2 to 18 and L3 / L2 to 1.2 to 15, it is possible to balance the space utilization rate of the battery cell 6 in the first direction X and the current passability of the first tab 12, reduce the temperature rise of the battery cell 6, reduce the risk of deformation when the battery cell 6 is subjected to external shock, and improve the reliability and cycle performance of the battery cell 6.

[0153] Selectively, L1 / L3 may be 1, 2, 3, 4, 5, 7, 8, 10, 12, 14, 15, 17, or 18.

[0154] Selectively, L3 / L2 may be 1.2, 2, 3, 4, 5, 7, 8, 10, 12, 14, or 15.

[0155] In some examples, L1 / L3 is 3 to 7, and L3 / L2 is 2 to 7.

[0156] In some embodiments, L1 is 10mm to 3000mm. Selectively, L1 is 100mm to 1500mm. Selectively, L1 is 500mm to 1000mm.

[0157] For example, L1 can be 10mm, 50mm, 100mm, 300mm, 400mm, 500mm, 600mm, 1000mm, 1200mm, 1500mm, 2000mm, 2500mm, or 3000mm.

[0158] In some embodiments, L3 is 10mm to 3000mm. Selectively, L3 is 30mm to 1000mm. L3 is 50mm to 150mm.

[0159] Selectively, L3 can be 10mm, 50mm, 100mm, 150mm, 300mm, 400mm, 500mm, 600mm, 1000mm, 1200mm, 1500mm, 2000mm, 2500mm, or 3000mm.

[0160] In some embodiments, L2 is 5mm to 1000mm. Selectively, L2 is 10mm to 300mm. Selectively, L2 is 20mm to 50mm.

[0161] Selectively, L3 can be 5mm, 10mm, 30mm, 50mm, 60mm, 80mm, 100mm, 200mm, 300mm, 500mm, 600mm, 800mm, or 1000mm.

[0162] In some embodiments, when observed along the third direction Y, the first communication hole 20a and the second communication hole 20b are located on both sides of the main body 11 along the first direction X.

[0163] In some embodiments, the exterior casing 20 includes a casing 21 and a cover plate 22, the casing 21 having an opening, and the cover plate 22 covering the opening.

[0164] The first communication hole 20a may be installed in the casing 21 or in the cover plate 22. The second communication hole 20b may be installed in the casing 21 or in the cover plate 22.

[0165] Exemplary, the first communication hole 20a and the second communication hole 20b are provided in the cover plate 22, thereby simplifying the molding process of the casing 21.

[0166] In some embodiments, the battery cell 6 further includes a first electrode lead member 30 and a second electrode lead member 40, the first electrode lead member 30 being installed in the outer casing 20 and electrically connected to a first tab 12, and the second electrode lead member 40 being installed in the outer casing 20 and connected to a second tab 13.

[0167] The first electrode extraction member 30 and the second electrode extraction member 40 are used to electrically connect the electrode assembly 10 to the external current of the battery cell 6, thereby enabling charging and discharging of the battery cell 6.

[0168] In some embodiments, both the first electrode extraction member 30 and the second electrode extraction member 40 are attached to the cover plate 22.

[0169] In some embodiments, the first electrode lead member 30 includes an adapter 31, electrode terminals 32, and a terminal board 33, the terminal board 33 being located outside the cover plate 22, the adapter 31 being installed in the housing cavity 20c and connected to the first tab 12, and the electrode terminals 32 passing through the cover plate 22 and connecting the adapter 31 and the terminal board 33. Exemplarily, the terminal board 33 may be used to connect to a bus member. Selectively, the adapter 31 and the electrode terminals 32 are integrally constructed.

[0170] In some embodiments, the cover plate 22, the first electrode lead member 30, the second electrode lead member 40, and other members can be pre-assembled as a cover plate assembly, then the cover plate assembly can be connected to the electrode assembly 10, and then the cover plate 22 can be covered with the casing 21 to connect the cover plate 22 and the casing 21.

[0171] In some embodiments, the second communication hole 20b is used for injecting electrolytes. The first communication hole 20a and the second communication hole 20b can be used simultaneously for injecting electrolytes to improve the efficiency of electrolyte injection.

[0172] In some embodiments, the minimum diameter of the second communication hole 20b is less than or equal to the minimum diameter of the first communication hole 20a.

[0173] For example, for a non-circular connecting hole, if the area of ​​a certain cross-section (i.e., the area of ​​a cross-section perpendicular to the axial direction of the connecting hole) is K, then the diameter of the non-circular hole at that cross-section is as follows: 2 × √(K / π).

[0174] Correspondingly, the minimum hole diameter for a non-circular connecting hole is the hole diameter calculated from the area of ​​the smallest cross-section.

[0175] To ensure clarity, the terms diameter, inner diameter, and outer diameter described below also apply to non-circular structures. The diameter, inner diameter, and outer diameter of non-circular structures may also be calculated using area, as described above.

[0176] In some embodiments, the minimum diameter of the second communication hole 20b is equal to the minimum diameter of the first communication hole 20a. Selectively, the shape and dimensions of the second communication hole 20b and the first communication hole 20a are the same, and thus the first communication hole 20a and the second communication hole 20b are interchangeable, and the external equipment may inject the electrolyte into the containment cavity 20c through the first communication hole 20a or through the second communication hole 20b.

[0177] In some embodiments, the minimum diameter of the second communication hole 20b is smaller than the minimum diameter of the first communication hole 20a. During the liquid injection process, the second communication hole 20b is used to evacuate and stabilize the air pressure. Since gas has higher fluidity than liquid, reducing the diameter of the second communication hole 20b can reduce the loss of strength of the outer casing 20.

[0178] In some embodiments, the first communication hole 20a and the second communication hole 20b are positioned diagonally to improve the permeability of the electrolyte to the electrode assembly 10.

[0179] For example, the exterior casing 20 has four corners, with the first communication hole 20a and the second communication hole 20b located in two opposing corners, respectively.

[0180] In some embodiments, the outer casing 20 includes a first casing wall 23 and a second casing wall 24 installed opposite each other along a second direction Z, the main body 11 is located between the first casing wall 23 and the second casing wall 24, and the second direction Z is parallel to the thickness direction of the battery cell 6 and perpendicular to the first direction X.

[0181] The first casing wall 23 is a wall of the exterior casing 20 with a constant thickness, and the second casing wall 24 is a wall of the exterior casing 20 with a constant thickness. The first casing wall 23 and the second casing wall 24 are installed with a gap between them along the second direction Z.

[0182] The first casing wall 23 may have various shapes, such as circular, rectangular, square, or other shapes. The second casing wall 24 may have various shapes, such as circular, rectangular, square, or other shapes.

[0183] The first casing wall 23 may be a flat wall or a curved wall. The second casing wall 24 may be a flat wall or a curved wall.

[0184] For example, the area of ​​the second casing wall 24 may be equal to the area of ​​the first casing wall 23. For instance, the shape and dimensions of the second casing wall 24 and the first casing wall 23 may be the same. Alternatively, the area of ​​the second exterior casing wall 24 may be smaller than the area of ​​the first exterior casing wall 23.

[0185] The first communication hole 20a may be installed in the first casing wall 23 or in the second casing wall 24. The second communication hole 20b may be installed in the first casing wall 23 or in the second casing wall 24, or in any other casing wall of the exterior casing 20.

[0186] In some embodiments, the cover plate 22 includes a first casing wall 23, and the casing 21 includes a second casing wall 24.

[0187] In some embodiments, the first casing wall 23 is a flat wall, and the first communication hole 20a is installed in the first casing wall 23. The first casing wall 23 is located on the side along the thickness direction of the electrode assembly 10, is relatively flat, and has a relatively large area, making it easy to install the first communication hole 20a.

[0188] In some embodiments, the axial direction of the first communication hole 20a is parallel to the second direction Z.

[0189] In some embodiments, both the first communication hole 20a and the second communication hole 20b are installed in the first casing wall 23. Selectively, the first communication hole 20a and the second communication hole 20b are provided at two opposing corners of the first casing wall 23, so that the first communication hole 20a and the second communication hole 20b are installed diagonally.

[0190] In some embodiments, the minimum diameter of the first communication hole 20a is D1, the dimension of the first casing 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.

[0191] Pore ​​diameter can refer to the diameter of a hole.

[0192] D1 is positively correlated with the electrolyte injection efficiency. W correlates with the degree of electrolyte infiltration into the electrode assembly 10; for example, the larger W is, the greater the maximum distance between the first communication hole 20a and the edge of the first casing wall 23 in the third direction Y, and the closer to the first communication hole 20a, the easier the infiltration.

[0193] Furthermore, by providing the first communication hole 20a, the strength of the first casing wall 23 is affected, and the larger D1 is, the lower the strength of the first casing wall 23 at the first communication hole 20a.

[0194] In the embodiments of the present invention, limiting D1 / W to 0.02 or more improves the injection efficiency of the electrolyte and improves the uniformity of the electrolyte infiltration into the electrode assembly 10. In the embodiments of the present invention, limiting D1 / W to 0.2 or less reduces the strength loss at the first communication hole 20a of the first casing wall 23, thereby reducing the risk of the first casing wall 23 cracking when the battery cell 6 is subjected to external impact and improving reliability.

[0195] For example, 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.

[0196] In some embodiments, D1 / W is between 0.04 and 0.1.

[0197] In some embodiments, W may be a dimension along the third direction Y of the cover plate 22.

[0198] In some embodiments, W may be equal to L3.

[0199] In some embodiments, 2 mm ≤ D1 ≤ 10 mm. Selectively, D1 is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0200] In the embodiments of the present invention, D1 is limited to 2 mm or more in order to improve the electrolyte injection efficiency, and D1 is limited to 10 mm or less in order to reduce the strength loss of the first casing wall 23 and to reduce the requirements for the liquid injection equipment.

[0201] Furthermore, by limiting D1 to 2 mm or more, the current passage area of ​​the first communication hole 20a can be increased. This reduces the electrolyte flow rate, reduces the impact force of the electrolyte on the main body 11, minimizes deformation of the main body 11, and improves the reliability of the battery cell 6, while the electrolyte injection speed meets the requirements.

[0202] In some embodiments, D1 is 3mm to 8mm. Selectively, D1 is 5mm to 7mm.

[0203] In some embodiments, the battery cell 6 further includes a first sealing member 50 which is connected to the outer casing 20 and used to seal the first communication hole 20a.

[0204] The first sealing member 50 is used to seal the first communication hole 20a in order to reduce the risk of the housing cavity 20c communicating with the external space of the battery cell 6 through the first communication hole 20a.

[0205] The first sealing member 50 may be inserted into the first communication hole 20a, or the entire member may be located outside the first communication hole 20a.

[0206] The first sealing member 50 can be connected to the outer casing 20 by welding, bonding, engaging or other means to seal the first communication hole 20a.

[0207] The first sealing member 50 may have a plate-like structure, a columnar structure, or other structure.

[0208] The material of the first sealing member 50 may include metal, rubber, or other materials.

[0209] In the embodiment of the present invention, by installing the first sealing member 50, the first communication hole 20a is sealed, reducing the risk of electrolyte leakage through the first communication hole 20a and improving the reliability of the battery cell 6.

[0210] In some embodiments, the first communication hole 20a is installed in the first casing wall 23, and the first sealing member 50 is connected to the first casing wall 23.

[0211] In some embodiments, in the second direction Z, the projection of the first communication hole 20a is located within the projection of the first sealing member 50.

[0212] In some embodiments, the first sealing member 50 includes a first protrusion 51 and a connecting portion 52 positioned around the first protrusion 51, the connecting portion 52 being located outside the outer casing 20 and connected to the outer casing 20, and the first protrusion 51 protruding from the surface of the connecting portion 52 away from the outer casing 20.

[0213] The first protrusion 51 may be a solid structure or a hollow structure.

[0214] The first protrusion 51 can act as a reinforcing rib, thereby improving the strength of the outer casing 20 at the first communication hole 20a, reducing the risk of the outer casing 20 cracking around the first communication hole 20a when the battery cell 6 is subjected to external impact, and improving the reliability of the battery cell 6.

[0215] In some embodiments, the connector 52 is located outside the first casing wall 23 and is connected to the first casing wall 23. The first projection 51 protrudes from the surface away from the first casing wall 23 along the second direction Z of the connector 52.

[0216] In some embodiments, the first sealing member 50 is provided with a first recess 53 at a position corresponding to the first protrusion 51, and the first recess 53 is recessed relative to the surface of the connecting portion 52 facing the outer casing 20.

[0217] By installing 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 improved.

[0218] For example, the first recess 53 is recessed relative to the surface of the connecting portion 52 that faces the first casing wall 23.

[0219] For example, the first sealing member 50 can be manufactured by stamping a plate-like structure. The pressurized positions of the plate-like structure form a first convex portion 51 and a first concave portion 53.

[0220] In some embodiments, by installing a first sealing member 50 having a first protrusion 51, the overall strength of the outer casing 20 can be improved, and the diameter of the first communication hole 20a can be increased by an appropriate amount to improve the electrolyte injection efficiency.

[0221] In some embodiments, the dimension H2 by which the first protrusion 51 protrudes from the outer surface of the first casing wall 23 in the axial direction of the first communication hole 20a satisfies the condition 0.5 mm ≤ H2 ≤ 2 mm.

[0222] Selectively, H2 is 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm.

[0223] In the embodiments of the present invention, limiting H2 to 0.5 mm or more improves the strength of the first sealing member 50, reinforces the strength of the outer casing 20, reduces the risk of cracking of the outer casing 20, and improves the reliability of the battery cell 6. Limiting H2 to 2 mm or less reduces the space that the first sealing member 50 occupies extra in the axial direction of the first communication hole 20a, thereby reducing the loss of energy density of the battery cell 6.

[0224] In some embodiments, the dimension by which the first protrusion 51 protrudes from the outer surface of the first casing wall 23 in the second direction Z is H2.

[0225] In some embodiments, the battery cell 6 further includes a second sealing member 60, a portion of which is inserted into the first communication hole 20a.

[0226] The second sealing member 60 and the first sealing member 50 can perform a double seal, thereby improving sealing performance, reducing the risk of electrolyte leakage, and improving the reliability of the battery cell 6.

[0227] In some embodiments, the second sealing member 60 is removably connected to the first casing wall 23.

[0228] The second sealing member 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 sealing member 60 can be inserted into the first communication hole 20a to seal the first communication hole 20a, and then the battery cell 6 can be transported to another work station. If it is necessary to reuse the first communication hole 20a (for example, in the chemical process, the first communication hole 20a can be used to draw out gases generated by side reactions inside the battery cell 6), the second sealing member 60 can be removed, and then the battery cell 6 can be processed.

[0229] After all processes related to the first communication hole 20a are completed, the first sealing member 50 is attached to the first casing wall 23.

[0230] In some embodiments, a portion of the second sealing member 60 is inserted into the first communication hole 20a, and the other portion of the second sealing member 60 is housed in the first recess 53.

[0231] The first recess 53 not only avoids the second sealing member 60, but also restricts and fixes the position of the second sealing member 60, reducing the risk of the second sealing member 60 loosening when the battery cell 6 is subjected to external impact, thereby improving the sealing performance and reliability of the battery cell 6.

[0232] In some embodiments, an exterior casing recess 25 is provided on the outside of the exterior casing 20.

[0233] By installing the recess 25 in the outer casing, the volume of the battery cell 6 can be reduced, thereby improving the energy density.

[0234] In some embodiments, in the second direction Z, the first sealing member 50 is located on the side of the outer casing 20 away from the outer casing recess 25.

[0235] When multiple battery cells 6 are arranged along a second direction Z, the outer casing recess 25 of one battery cell 6 can avoid the first sealing member 50 of another battery cell 6, thereby improving space utilization and increasing the energy density of the battery.

[0236] In some embodiments, the exterior casing recess 25 is recessed relative to the surface of the second casing wall 24 that is separated from the main body 11. Selectively, in the second direction Z, the projection of the first sealing member 50 is located within the projection of the exterior casing recess 25.

[0237] In some embodiments, the battery cell 6 is provided with two outer casing recesses 25, the two outer casing recesses 25 being located on either side of the second casing 21 along the first direction X.

[0238] In some embodiments, in the second direction Z, the projection of the portion of the first electrode extraction member 30 located outside the first casing wall 23 lies within the projection of one outer casing recess 25, and the projection of the portion of the second electrode extraction member 40 located outside the first casing wall 23 lies within the projection of one outer casing recess 25.

[0239] For example, when two battery cells 6 are arranged along a second direction Z, the two outer casing recesses 25 of one battery cell 6 can avoid the first electrode lead member 30 and the second electrode lead member 40 of the other battery cell 6, respectively.

[0240] In some embodiments, the second communication hole 20b is located in the first casing wall 23. Exemplarily, the axial direction of the second communication hole 20b is parallel to the second direction Z.

[0241] In some embodiments, in a second direction Z, the projection of the first communication hole 20a lies within the projection of the bottom wall of one exterior casing recess 25, and the projection of the second communication hole 20b lies within the projection of the bottom wall of another exterior casing recess 25.

[0242] In some embodiments, the first sealing member 50 is welded to the outer casing 20 to form a welded portion 70. Welding can improve the connection strength between the first sealing member 50 and the outer casing 20, and also improve the sealing performance.

[0243] For example, the first sealing member 50 is connected to the first casing wall 23 by laser welding, forming a welded portion 70.

[0244] In some embodiments, the outer casing 20 is provided with a pressure release mechanism. There may be one or more pressure release mechanisms.

[0245] The pressure release mechanism has a significant impact on the reliability of the battery cell 6. For example, if a short circuit or overcharging occurs, thermal runaway may occur inside the battery cell 6, potentially causing a sudden increase in pressure. In this case, the pressure release mechanism releases the internal pressure to the outside, reducing the risk of explosion or fire of the battery cell 6.

[0246] A pressure release mechanism refers to an element or component that activates and releases internal pressure when the internal pressure of the battery cell 6 reaches a predetermined threshold. The design of this threshold varies depending on the design needs. This threshold may depend on one or more materials among the positive electrode, negative electrode, electrolyte, and separator in the battery cell 6.

[0247] In some embodiments, a pressure release mechanism is provided in the first casing wall 23.

[0248] In some examples, the first casing wall 23 and the pressure release mechanism may be integrally molded. In alternative examples, the pressure release mechanism and the first casing wall 23 may be independently molded components, and they may be connected by welding, bonding, or other means. For example, the first casing wall 23 may be provided with a pressure release hole that penetrates the first casing wall 23, and the pressure release mechanism may be attached to the first casing wall 23 and cover the pressure release hole, thereby separating the spaces on both the inside and outside of the first casing wall 23.

[0249] In some embodiments, the first casing wall 23 and the pressure release mechanism are formed integrally.

[0250] In some embodiments, a weak portion 231 is provided in the first casing wall 23. For example, by providing the weak portion 231, a pressure release mechanism is formed in the first casing wall 23.

[0251] The strength of the weak point 231 is lower than the strength of the rest of the first casing wall 23, and the weak point 231 is a part that is prone to fracture, shattering, tearing, or opening.

[0252] In some examples, by providing grooves, notches, or other structures in a predetermined area of ​​the first casing wall 23, the local strength of the first casing wall 23 can be reduced, and a weak area 231 can be formed in the first casing wall 23. For example, by performing a thinning treatment on a predetermined area of ​​the first casing wall 23, the thinned portion of the first casing wall 23 forms a weak area 231. In some other examples, by performing a material treatment on a predetermined area of ​​the first casing wall 23, the strength of that area can be made lower than the strength of other areas, in other words, that area becomes a weak area 231.

[0253] When the battery cell 6 experiences thermal runaway, the vulnerable portion 231 ruptures under the influence of the internal pressure or temperature of the battery cell 6, forming a passage to release the internal pressure. This allows for timely release of pressure, reducing the risk of ignition and explosion of the battery cell 6 and improving its reliability.

[0254] In some embodiments, there may be four weak points 231, and the four weak points 231 may be located at the four corners of the first casing wall 23, respectively.

[0255] In some embodiments, the outer casing 20 is provided with a weak portion 231, and the minimum distance D3 between the welded portion 70 and the weak portion 231 is 1 mm or more.

[0256] During welding, heat is conducted to the area surrounding the molten pool, thereby creating a heat-affected zone. In the embodiment of this application, by limiting D3 to 1 mm or more, the influence of the heat-affected zone on the weak portion 231 is reduced, the thermal stress that the weak portion 231 receives after welding is reduced, the risk of fracture failure of the weak portion 231 is reduced, and the reliability of the battery cell 6 is improved.

[0257] Selectively, D3 can be 1mm, 2mm, 3mm, 4mm, 5mm, or 10mm.

[0258] For example, D3 is 2 mm or more.

[0259] In some embodiments, the area of ​​the welded portion 70 is S1, the area of ​​the minimum cross-sectional area of ​​the first communication hole 20a perpendicular to its own axial direction is S2, and 1.5 ≤ S1 / S2 ≤ 5.

[0260] For example, S² = π × (D¹ / ²) 2 That is the case.

[0261] The larger S2 is, the higher the requirements for connection strength between the first sealing member 50 and the outer casing 20, which in turn increases the requirements for S1. Of course, the larger S1 is, the higher the risk that the welded joint 70 will have a thermal impact on other structures.

[0262] In view of this, in the embodiment of the present application, by limiting S1 / S2 to 1.5 or more, the connection strength between the first sealing member 50 and the outer casing 20 is improved, the structural strength around the first communication hole 20a of the battery cell 6 is improved, and the risk of cracking around the first communication hole 20a of the outer casing 20 is reduced. In the embodiment of the present application, by limiting S1 / S2 to 5 or less, the heat-affected zone due to welding is limited, and the risk of other structures of the battery cell 6 (e.g., weak parts 231, first electrode extraction member 30, etc.) failing under the action of thermal stress is reduced.

[0263] Selectively, S1 / S2 is 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5.

[0264] Selectively, the S1 / S2 ratio is between 2.5 and 4.

[0265] In some embodiments, the weld 70 is annular. The annular weld 70 can serve a sealing function that reduces the risk of external impurities entering the first communication hole 20a from between the first sealing member 50 and the first casing wall 23.

[0266] For example, the outer diameter of the weld 70 is D2, and the inner diameter of the weld 70 is D7. S1 = π × (D2 / 2) 2 -π × (D7 / 2) 2 That is the case.

[0267] In some embodiments, the outer diameter of the welded joint 70 is D2, the minimum hole diameter of the first communication hole 20a is D1, and 1.6 ≤ D2 / D1 ≤ 2.5.

[0268] In the embodiments of the present application, by limiting D2 / D1 to 1.6 or more, the strength of the welded portion 70 is improved, the structural strength around the first communication hole 20a of the battery cell 6 is enhanced, and the risk of the outer casing 20 cracking around the first communication hole 20a is reduced. In the embodiments of the present application, by limiting D2 / D1 to 2.5 or less, the heat-affected zone caused by welding is restricted, and the risk of other structures of the battery cell 6 failing under the action of thermal stress is reduced.

[0269] Alternatively, D2 / D1 is 1.6, 1.8, 2, 2.2, 2.4 or 2.5.

[0270] Alternatively, D2 / D1 is in the range of 1.8 to 2.2.

[0271] In some embodiments, the outer casing 20 is provided with a second recess 232, and the first communication hole 20a extends inward from the bottom surface 232a of the second recess 232. Illustratively, the first communication hole 20a extends inward along the second direction Z from the bottom surface 232a of the second recess 232.

[0272] When injecting the electrolyte, the bottom surface 232a of the second recess 232 can play a positioning role, and the liquid injection equipment abuts against the bottom surface 232a of the second recess 232, so that the sputtering of the electrolyte to the outside can be reduced.

[0273] In some embodiments, the outer casing 20 includes a first casing wall 23. The first casing wall 23 includes a wall main body 233 and a first convex wall 234, at least a part of the first convex wall 234 protrudes from the surface of the wall main body 233 facing the main body portion 11, and is located on the side of the main body portion 11 along the first direction X. The first convex wall 234 includes a first wall body 234a for defining the first communication hole 20a.

[0274] By providing the first convex wall 234 protruding inward, the depth of the first communication hole 20a can be increased, the structural strength of the first casing wall 23 around the first communication hole 20a is improved, and the deformation of the first casing wall 23 can be reduced.

[0275] In some embodiments, the projection of the main body 11 along the second direction Z lies within the projection of the wall body 233 along the second direction Z.

[0276] In some embodiments, the wall body 233 is flat.

[0277] In some embodiments, the thickness direction of the wall body 233 is parallel to the second direction Z.

[0278] In some embodiments, the projection of the first wall 234a along the first direction X lies within the projection of the main body 11 along the first direction X.

[0279] In some embodiments, the dimension of the first wall 234a along the second direction Z is H1, the minimum hole diameter of the first communication hole 20a is D1, and 0.2 ≤ H1 / D1 ≤ 1. The second direction is parallel to the thickness direction of the wall body.

[0280] In the embodiments of this application, limiting H1 / D1 to 0.2 or more improves the structural strength and stability of the first wall 234a and reduces the risk of deformation and cracking of the first wall 234a. In the embodiments of this application, limiting H1 / D1 to 1 or less reduces the space occupied by the first wall 234a in relation to the internal space of the outer casing 20, thereby reducing the resistance of electrolyte flow in the outer casing 20 and improving the injection efficiency.

[0281] Selectively, H1 / D1 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0282] Selectively, the H1 / D1 ratio is between 0.3 and 0.6.

[0283] In some embodiments, H1 is 0.5 mm to 10 mm. Selectively, H1 is 1 mm to 5 mm.

[0284] For example, H1 can be 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 5mm, 6mm, 8mm, or 10mm.

[0285] 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 communication hole 20a and removably connected to the first convex wall 234.

[0286] The second sealing member 60 can be used to seal the first communication hole 20a and improve the sealing performance of the battery cell 6. The second sealing member 60 can be attached and detached multiple times during the production process of the battery cell 6, facilitating multiple processing steps for the battery cell 6 through the first communication hole 20a. The first convex wall 234 has a relatively 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.

[0287] In some embodiments, the second sealing member 60 is an interference fit with the first communication hole 20a. The interference fit method not only effectively seals the first communication hole 20a, but also allows for easy attachment and detachment of the second sealing member 60.

[0288] In some embodiments, the material of the second sealing member 60 is an elastic material. Selectively, the material of the second sealing member 60 includes rubber.

[0289] In several embodiments, the structure of the first communication hole 20a and the second communication hole 20b are the same.

[0290] Exemplary, the first casing wall 23 further includes a second convex wall (not shown), at least a portion of which is used to define a second communication hole 20b. Exemplary, the structure of the second convex wall is the same as that of the first convex wall 234.

[0291] For example, the battery cell 6 further includes a third sealing member (not shown) and a fourth sealing member (not shown) for sealing the second communication hole 20b. Alternatively, the structure of the third sealing member may be the same as the structure of the first sealing member 50, and the structure of the fourth sealing member may be the same as the structure of the second sealing member 60.

[0292] FIG. 10 is a schematic cross-sectional view of the second sealing member of the battery cell provided according to some embodiments of the present application.

[0293] In some embodiments, with reference to FIG. 7 to FIG. 10, the second sealing member 60 includes a large end 61 and a small end 62 disposed opposite to each other along the axial direction of the first communication hole, and the small end 62 is located inside the large end 61. The ratio of the diameter D4 of the small end 62 to the minimum hole diameter D1 of the first communication hole 20a is 0.95 to 1.05, and the diameter D5 of the large end 61 is larger than the maximum hole diameter of the first communication hole 20a.

[0294] In the embodiments of the present application, the large end 61 is not required to be the portion with the largest diameter of the second sealing member 60, as long as its diameter is larger than the diameter of the small end 62. Similarly, the small end 62 is also not required to be the portion with the smallest diameter of the second sealing member 60.

[0295] In the embodiments of the present application, by limiting D4 / D1 to 0.95 to 1.05, the second sealing member 60 can be easily inserted into the first communication hole 20a. The large end 61 of the second sealing member 60 has a relatively large size, which reduces the risk of the second sealing member 60 falling into the receiving cavity 20c through the first communication hole 20a, and can effectively cover the first communication hole 20a to improve the sealing performance.

[0296] In some embodiments, D5 / D1 is 1.15 to 1.4.

[0297] In some embodiments, H1 is 1 mm or more, which increases the contact dimension between the second sealing member 60 and the first wall 234a along the second direction Z, thereby improving the stability of the second sealing member 60.

[0298] In some embodiments, the second sealing member 60 is frustoconical. Selectively, the taper of the second sealing member 60 is 9 to 20 degrees, thereby reducing the difficulty of inserting the second sealing member 60 into the first communication hole 20a and improving the interference fit between the second sealing member 60 and the first communication hole 20a.

[0299] In some embodiments, the large end 61 of the second sealing member 60 is housed in the first recess 53 of the first sealing member 50. The first recess 53 can restrict the position of the large end 61 of the second sealing member 60, limit the loosening of the second sealing member 60, and reduce the risk of interference fit failure between the second sealing member 60 and the first communication hole 20a.

[0300] In some embodiments, the edge of the large end 61 of the second sealing member 60 is provided with a chamfer so as to fit with the chamfer of the edge of the first recess 53.

[0301] In some embodiments, the first sealing member 50 presses against the second sealing member 60 in the second direction Z.

[0302] In some embodiments, the first sealing member 50 is located on the outside of the wall body 233. The connecting portion 52 of the first sealing member 50 is bonded to the outer surface of the wall body 233.

[0303] In some embodiments, the first convex wall 234 further includes a second wall 234b, which is installed surrounding 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 is used to define a second recess 232, the second recess 232 is recessed from the outer surface of the wall body 233, and the first communication 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 housed in the second recess 232.

[0304] The second wall 234b forms a structure with an inward projection and an outward recess, which improves the strength of the first casing wall 23 and reduces the risk of deformation and cracking of the first casing wall 23. The second recess 232 further accommodates a portion of the second sealing member 60, thereby reducing the space that the second sealing member 60 occupies extra in the axial direction of the first communication hole, and thereby improving the space utilization rate.

[0305] In some embodiments, the end of the first wall 234a connected to the second wall 234b is bent into an arc shape to distribute stress during the molding process of the first convex wall 234.

[0306] In some embodiments, the minimum distance between the second recess 232 and the weak portion 231 in any direction perpendicular to the second direction Z is 2 mm or more.

[0307] Figure 11 is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some other embodiments of the present application, and Figure 12 is a schematic cross-sectional view of a second sealing member in a battery cell provided in some other embodiments of the present application.

[0308] Referring to Figures 11 and 12, in some embodiments, an annular third recess 63 is provided on the outer circumference of the second sealing member 60, and at least a portion of the first wall 234a is housed in the third recess 63.

[0309] The first wall 234a can be inserted into the third recess 63 and form a rivet joint structure with the second sealing member 60, thereby restricting the movement of the second sealing member 60 in the second direction Z, improving the stability of the second sealing member 60, and improving the sealing performance.

[0310] In some embodiments, the bottom surface of the third recess 63 is bonded to the first wall 234a.

[0311] In some embodiments, after the second sealing member 60 is inserted into the first communication hole 20a, the third recess 63 can be deformed under pressure from the first wall 234a.

[0312] Figure 13 is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some further embodiments of the present application.

[0313] As shown in Figure 13, in some embodiments, the first sealing member 50 may have a flat plate structure. The flat plate structure reduces the space occupied by the first sealing member 50 in the second direction Z and simplifies the molding process of the first sealing member 50.

[0314] Figure 14 is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some further embodiments of the present application, and Figure 15 is a schematic view of the first casing wall shown in Figure 14.

[0315] As shown in Figures 14 and 15, in some embodiments, at least a portion of the first sealing member 50 is positioned to be housed in the second recess 232.

[0316] When assembling the first sealing member 50, the second recess 232 plays a positioning role, thereby simplifying the assembly process of the first sealing member 50. By providing the second recess 232, the space that the first sealing member 50 occupies extra in the axial direction of the first communication hole is reduced, thereby improving space utilization.

[0317] In some embodiments, the second wall 234b includes a stepped surface 232b, and in the axial direction of the first communication 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 communication hole surrounds the projection of the bottom surface 232a of the second recess 232 along the axial direction of the first communication hole. At least a portion of the first sealing member 50 is housed in the second recess 232 and in contact with the stepped surface 232b.

[0318] By installing a stair surface, the overall structural strength of the second wall 234b can be improved. The stair surface 232b and the bottom surface 232a of the second recess 232 restrict the positions of the first sealing member 50 and the second sealing member 60, respectively, and reduce the risk of the second sealing member 60 being subjected to pressure and spreading between the first sealing member 50 and the stair surface 232b. This also helps to some extent to avoid the second sealing member 60 interfering with the connection between the first sealing member 50 and the second wall 234b, thereby improving reliability.

[0319] In some embodiments, the entire connecting portion 52 is housed within the second recess 232.

[0320] In some embodiments, the distance between the outer surface of the wall body 233 and the stair surface 232b in the second direction Z is 0.3 mm to 1 mm. Selectively, the distance between the outer surface of the wall body 233 and the stair surface 232b is 0.3 mm, 0.5 mm, 0.7 mm, 0.8 mm, or 1 mm.

[0321] In some embodiments, the area of ​​the stair surface 232b is S3, and S3 / S2 is 1.5 to 5.

[0322] In the embodiments of the present invention, limiting S3 / S2 to 1.5 or more increases the welding area between the first sealing member 50 and the second wall 234b, thereby improving the connection strength. In the embodiments of the present invention, limiting S3 / S2 to 5 or less limits the total area of ​​the second recess 232, thereby reducing the risk of interference between the first convex wall 234 and other structures of the battery cell 6.

[0323] In some embodiments, the stepped surface 232b is an annular plane.

[0324] In some embodiments, S3 / S2 is selectively 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5. Selectively, S3 / S2 is between 2.5 and 4.

[0325] In some embodiments, the maximum diameter of the second recess 232 is D6. D6 / D1 may be between 1.6 and 2.5.

[0326] In the embodiments of the present application, by limiting D6 / D1 to 1.6 or more, the welding area between the first sealing member 50 and the second wall 234b is increased, improving the structural strength around the first communication hole 20a of the battery cell 6 and reducing the risk of the first casing wall 23 cracking around the first communication hole 20a. In the embodiments of the present application, by limiting D6 / D1 to 2.5 or less, the total area of ​​the second recess 232 is limited, reducing the risk of interference between the first convex wall 234 and other structures of the battery cell 6.

[0327] Selectively, D6 / D1 is 1.6, 1.8, 2, 2.2, 2.4, or 2.5.

[0328] Selectively, the D6 / D1 ratio is between 1.8 and 2.2.

[0329] Figure 16 is a schematic local cross-sectional view of a first communication hole in a battery cell provided in some other embodiments of the present application, Figure 17 is a schematic structural view of a support provided in some other embodiments of the present application, Figure 18 is a schematic structural view of the insulating support shown in Figure 17 from a different angle, and Figure 19 is a schematic cross-sectional view along the BB direction of Figure 18.

[0330] Referring together to Figures 5 and 16-19, in some embodiments, the battery cell 6 further includes a support 80, the support 80 is provided with a drain recess 80a that communicates with the first communication hole 20a, and the drain recess 80a communicates with the space between the main body 11 and the support 80. In the axial direction of the first communication hole 20a, the first communication hole 20a faces the bottom wall 80b of the drain recess.

[0331] The bottom wall 80b of the drain recess receives the impact of the electrolyte and guides the electrolyte to flow in the drain recess 80a, thereby reducing the impact of the electrolyte on the main body 11 and reducing deformation of the separator of the main body 11. The support 80 can also support the outer casing 20 to reduce the risk of deformation of the outer casing 20 due to pressure from external equipment during the electrolyte injection process, thereby improving the reliability of the battery cell 6.

[0332] In some embodiments, the support 80 and the main body 11 are installed along a first direction X.

[0333] In some embodiments, a drain recess 80a is provided on the side of the support 80 facing the first casing wall 23.

[0334] In some embodiments, the exterior casing 20 includes a first casing wall 23. The first casing wall 23 includes a wall body 233 and a first convex wall 234, at least a portion of which protrudes from the surface of the wall body 233 facing the main body 11 and is located on the side of the main body 11 along a first direction X. The first convex wall 234 includes a first wall body 234a for defining a first communication hole 20a. At least a portion of the first wall body 234a is housed in a drain recess 80a and is spaced apart from the bottom wall 80b of the drain recess.

[0335] The drain recess 80a can also avoid the first wall 234a in order to provide more space to the first wall 234a and increase the depth of the first communication hole 20a.

[0336] In some embodiments, the support 80 is an insulating support.

[0337] In some embodiments, the drainage recess 80a forms an injection opening 80c on the surface of the support 80 facing the main body 11. The electrolyte can flow out through the injection opening 80c and permeate the main body 11.

[0338] In some embodiments, a portion of the second sealing member 60 extends into the drain recess 80a. Exemplarily, the small end 62 is housed in the drain recess 80a.

[0339] In some embodiments, the support 80 is attached to the wall body 233, thereby supporting the wall body 233 and reducing deformation of the wall body 233.

[0340] In some embodiments, the support 80 is fixed to the wall body 233.

[0341] In some embodiments, a receiving recess 80d is provided on the side of the support 80 facing the main body 11. At least a portion of the first tab 12 is housed in the receiving recess 80d. The support 80 can house the first tab 12 and separate at least a portion of the first tab 12 from the outer casing 20 to reduce the risk of short circuits. The receiving recess 80d can also converge the first tab 12 to reduce the risk of the first tab 12 coming apart.

[0342] In some embodiments, the support 80 includes two support blocks 81, and in a third direction Y, the receiving recess 80d is located between the two support blocks 81.

[0343] In some embodiments, the drain recess 80a is installed on a single support block 81. The support block 81 separates the drain recess 80a from the containment recess 80d to reduce the risk of the electrolyte directly colliding with the first tab 12.

[0344] In some embodiments, each support block 81 is provided with weight-reducing holes.

[0345] In some embodiments, the support 80 includes an insulating substrate 82, a first position limiting plate 83, a second position limiting plate 84, and a third position limiting plate 85, all of which are located on the side of the insulating substrate 82 facing the main body 11 and are installed sequentially spaced along a second direction Z. The third position limiting plate 85 is closer to the first casing wall 23 than the first position limiting plate 83 and the second position limiting plate 84.

[0346] In the third direction Y, the first position limiting plate 83, the second position limiting plate 84, and the third position limiting plate 85 are all located between the two support blocks 81. The two support blocks 81, the first position limiting plate 83, the second position limiting plate 84, and the insulating substrate 82 define a housing recess 80d.

[0347] At least a portion of the third position limiting plate 85 is sandwiched between the adapter 31 and the first casing wall 23, thereby fixing the support 80 to the first casing wall 23.

[0348] According to some embodiments of the present application, the present application further provides a battery comprising a plurality of battery cells of any one of the above embodiments.

[0349] According to several embodiments of the present application, the present application further provides an electrical device comprising a battery cell of any one of the embodiments described above, wherein the battery cell is used to provide electrical energy to the electrical device. The electrical device may be any one of the above-described equipment or systems that uses the battery cell.

[0350] Referring to Figures 4 to 10, an embodiment of the present application provides a battery cell 6 including an electrode assembly 10, an outer casing 20, a first sealing member 50, and a second sealing member 60.

[0351] The electrode assembly 10 includes a main body 11, a first tab 12, and a second tab 13, the first tab 12 and the second tab 13 having opposite polarities and extending from both ends of the main body 11 along a first direction X.

[0352] The exterior casing 20 includes a casing 21 and a cover plate 22, the casing 21 having an opening on the side along the second direction Z, the cover plate 22 covering the opening and defining the casing 21 and the housing cavity 20c.

[0353] 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 protruding from the surface of the wall body 233 facing the main body 11, and the first convex wall 234 and the second convex wall are located on both sides of the main body 11 along the first direction X, respectively. Exemplarily, the first convex wall 234 and the second convex wall are installed along the diagonal direction of the cover plate 22.

[0354] The first convex wall 234 includes a first wall body 234a and a second wall body 234b, the first wall body 234a defining a first communication hole 20a, the second wall body 234b is installed surrounding the first wall body 234a and connecting 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, and the first communication hole 20a extends inward from the bottom surface 232a of the second recess 232. Exemplarily, the structure of the second convex wall is the same as the structure of the first convex wall 234.

[0355] The second sealing member 60 is inserted into the first communication hole 20a to seal the first communication 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 communication hole 20a.

[0356] At least a portion of the second convex wall is used to define the second communication hole 20b. The portion of the containment cavity 20c located on the side of the main body 11 facing the first tab 12 communicates with the first communication hole 20a, and the portion of the containment cavity 20c located on the side of the main body 11 facing the second tab 13 communicates with the second communication hole 20b. The first communication hole 20a is used for injecting the electrolyte, and the second communication hole is used for exhausting during the electrolyte injection process.

[0357] In the axial direction of the first communication hole 20a, neither the first tab 12 nor the main body 11 overlaps with the first communication hole 20a. In the axial direction of the second communication hole 20b, neither the second tab 13 nor the main body 11 overlaps with the second communication hole 20b. The axial direction of the first communication hole 20a and the axial direction of the second communication hole 20b are both parallel to the second direction Z.

[0358] Referring to Figures 4 to 10, the embodiment of the present application provides a battery cell 6 including an electrode assembly 10, an outer casing 20, and a first sealing member 50.

[0359] The electrode assembly 10 includes a main body 11 and a first tab 12, the main body 11 including a first end face and a second end face positioned opposite each other along a first direction X, and the first tab 12 extending from the first end face.

[0360] The outer casing 20 includes a housing cavity 20c, and the electrode assembly 10 is installed in the housing cavity 20c. The outer casing 20 is provided with a first communication hole 20a and a second communication hole 20b. The first communication hole 20a and the second communication hole 20b are located on both sides of the main body 11 along the first direction X, respectively. The portion of the housing cavity 20c facing the first tab 12 of the main body 11 communicates with the first communication hole 20a, and the portion of the housing cavity 20c away from the first tab 12 of the main body 11 communicates with the second communication hole 20b. The first communication hole 20a is used for injecting electrolyte. In the axial direction of the first communication hole 20a, neither the first tab 12 nor the main body 11 overlaps with the first communication hole 20a. The exterior casing 20 includes a first casing wall 23, the first casing wall 23 includes a wall body 233 and a first convex wall 234, at least a portion of which protrudes from the surface of the wall body 233 facing the main body 11 and is located on the side of the main body 11 along a first direction X, and the first convex wall 234 includes a first wall body 234a for defining a first communication hole 20a.

[0361] The first sealing member 50 includes a first protrusion 51 and a connecting portion 52 installed surrounding the first protrusion 51, the connecting portion 52 being located outside the first casing wall 23 and connected to the first casing wall 23. The first protrusion 51 protrudes from the surface of the connecting portion 52 away from the first casing wall 23, and the first sealing member 50 is provided with a first recess 53 at a position corresponding to the first protrusion 51, the first recess 53 being recessed relative to the surface of the connecting portion 52 facing the first casing wall 23.

[0362] While the present application has been described with reference to preferred embodiments, various improvements can be made thereto without departing from the scope of the application, and components therein can be replaced with equivalents, and any of the technical features mentioned in each embodiment can be combined in any way, especially unless there is a structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical ideas contained in the claims.

Claims

1. An electrode assembly comprising a main body and a first tab, wherein the first tab extends from one end of the main body along a first direction, An outer casing comprising a housing cavity, wherein the electrode assembly is installed in the housing cavity, the outer casing is provided with a first communication hole and a second communication hole, the portion of the housing cavity located on the side of the main body facing the first tab communicates with the first communication hole, the portion of the housing cavity located on the side of the main body away from the first tab communicates with the second communication hole, the first communication hole is used for injecting an electrolyte, and in the axial direction of the first communication hole, neither the first tab nor the main body overlaps with the first communication hole, the outer casing and Battery cells, including

2. The outer casing includes a first casing wall and a second casing wall installed opposite to each other along a second direction, the main body being located between the first casing wall and the second casing wall, the second direction being parallel to the thickness direction of the battery cell and perpendicular to the first direction, The first casing wall is a flat wall, and the first communication hole is installed in the first casing wall. The battery cell according to claim 1.

3. The minimum diameter of the first communication hole is D1, the dimension of the first casing wall along the third direction is W, and the third direction is perpendicular to the first and second directions. 0.02 ≤ D1 / W ≤ 0.2 The battery cell according to claim 2.

4. The battery cell according to claim 3, wherein 2 mm ≤ D1 ≤ 10 mm.

5. A battery cell according to any one of claims 1 to 4, further comprising a first sealing member, the first sealing member being connected to the outer casing and used to seal the first communication hole.

6. The battery cell according to claim 5, wherein the first sealing member includes a first protrusion and a connecting portion installed surrounding the first protrusion, the connecting portion being located outside the outer casing and connected to the outer casing, and the first protrusion protruding from the surface of the connecting portion away from the outer casing.

7. The battery cell according to claim 6, wherein, in the axial direction of the first communication hole, the dimension H2 of the first protrusion protruding from the outer surface of the outer casing satisfies 0.5 mm ≤ H2 ≤ 2 mm.

8. The battery cell according to claim 6 or 7, wherein the first sealing member has a first recess at a position corresponding to the first protrusion, and the first recess is recessed relative to the surface of the connecting portion facing the outer casing.

9. The battery cell according to claim 8, further comprising a second sealing member, a portion of which is inserted into the first communication hole, and the other portion of which is housed in the first recess.

10. An outer casing recess is provided on the outside of the outer casing. In the second direction, the first sealing member is located on the side of the outer casing away from the outer casing recess, and the second direction is perpendicular to the first direction. A battery cell according to any one of claims 5 to 9.

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

12. The battery cell according to claim 11, wherein the outer casing is provided with a weak portion, and the minimum distance between the welded portion and the weak portion is 1 mm or more.

13. The battery cell according to claim 11 or 12, wherein the welded portion is annular, the outer diameter of the welded portion is D2, the minimum hole diameter of the first communication 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 welded portion is S1, the area of ​​the smallest cross-section of the first communication hole perpendicular to its own axial direction is S2, and 1.5 ≤ S1 / S2 ≤ 5.

15. The outer casing is provided with a second recess, and the first communication hole extends inward from the bottom surface of the second recess. The battery cell according to any one of claims 5 to 14, wherein at least a portion of the first sealing member is installed to be housed in the second recess.

16. The battery cell according to any one of claims 1 to 15, further comprising the second sealing member, a portion of which is inserted into the first communication hole.

17. The exterior casing includes the first casing wall, the first casing wall includes a wall body and a first protruding wall, at least a portion of the first protruding wall protrudes from the surface of the wall body facing the main body and is located on the side of the main body along the first direction. The first convex wall includes a first wall body for defining the first communication hole. A battery cell according to any one of claims 1 to 16.

18. The battery cell according to claim 17, wherein the dimension of the first wall along the second direction is H1, the minimum hole diameter of the first communication hole is D1, 0.2 ≤ H1 / D1 ≤ 1, and the second direction is parallel to the thickness direction of the wall body.

19. The battery cell according to claim 17 or 18, further comprising the second sealing member, wherein at least a portion of the second sealing member is inserted into the first communication hole and is removably connected to the first convex wall.

20. The battery cell according to claim 19, wherein the second sealing member is an interference fit with the first communication hole.

21. The second sealing member comprises a large end and a small end that are positioned opposite each other along the axial direction of the first communication hole, the small end being located inside the large end, The ratio of the diameter of the small end to the minimum hole diameter of the first communication hole is 0.95 to 1.05, and the diameter of the large end is greater than the maximum hole diameter of the first communication hole. The battery cell according to claim 19 or 20.

22. A battery cell according to any one of claims 19 to 21, wherein an annular third recess is provided on the outer circumference of the second sealing member, and at least a portion of the first wall is housed in the third recess.

23. The first convex wall further includes a second wall body, the second wall body is installed surrounding the first wall body and connecting the wall body and the first wall body, the second wall body protrudes inward from the wall body and is used to define the second recess, the second recess is recessed from the outer surface of the wall body, and the first communication hole extends inward from the bottom surface of the second recess. At least a portion of the second sealing member is housed in the second recess. A battery cell according to any one of claims 19 to 22.

24. The second wall body has a stepped surface, and in the axial direction of the first communication 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 communication hole surrounds the projection of the bottom surface of the second recess along the axial direction of the first communication hole. The battery cell further includes the first sealing member, at least a portion of which is housed in the second recess and in contact with the stepped surface. The battery cell according to claim 23.

25. Further including a support, the support is housed within the outer casing, The support is provided with a drainage recess that communicates with the first communication hole, and the drainage recess communicates with the space located between the main body and the support. In the axial direction of the first communication hole, the first communication hole faces the bottom wall of the drain recess. A battery cell according to any one of claims 1 to 24.

26. The exterior casing includes the first casing wall, the first casing wall includes the wall body and the first protruding wall, at least a portion of the first protruding wall protrudes from the surface of the wall body facing the main body and is located on the side of the main body along the first direction, and the first protruding wall includes the first wall body for defining the first communication hole. At least a portion of the first wall is housed in the drain recess and is installed at a distance from the bottom wall of the drain recess. The battery cell according to claim 25.

27. The battery cell according to any one of claims 1 to 26, wherein the minimum diameter of the second communication hole is less than or equal to the minimum diameter of the first communication hole.

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

29. The exterior casing includes a casing and a cover plate, the casing having an opening, and the cover plate covering the opening. The first communication hole and the second communication hole are installed in the cover plate. A battery cell according to any one of claims 1 to 28.

30. The dimension of the outer casing along the first direction is L1, the dimension of the outer casing along the second direction is L2, and the dimension of the outer casing 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. A battery cell according to any one of claims 1 to 29.

31. A battery comprising a plurality of battery cells as described in any one of claims 1 to 30.

32. An electrical device comprising the battery described in claim 31.

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