Battery cell, manufacturing method therefor, battery, and electrical apparatus

Abstract

Disclosed in the present application are a battery cell, a manufacturing method therefor, a battery and an electrical apparatus. The battery cell comprises an electrode assembly, a casing and a first electrode terminal. The casing is provided with an accommodating cavity, the Brinell hardness of the casing being greater than or equal to 30 HB. The electrode assembly is arranged in the accommodating cavity, a first tab being provided at the end part of the electrode assembly in a first direction. The first electrode terminal is partially arranged in the accommodating cavity and is connected to the first tab, the first electrode terminal penetrating through the casing and extending to the outer side of the casing.

Description

Battery cell and manufacturing method thereof, battery and electric device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311454187.8, filed on November 03, 2023, entitled “Battery Cell, Battery, and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

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

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

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

[0006] Summary of the Invention

[0007] The present application provides a battery cell and a manufacturing method thereof, a battery, and an electrical device, which can improve energy density.

[0008] In a first aspect, the present application provides a battery cell comprising an electrode assembly, a housing, and a first electrode terminal. The housing has a receiving cavity and a Brinell hardness of 30 HB or greater. The electrode assembly is disposed in the receiving cavity, and a first electrode tab is provided at an end of the electrode assembly along a first direction. A portion of the first electrode terminal is disposed within the receiving cavity and connected to the first electrode tab, and the first electrode terminal extends through the housing and outside the housing.

[0009] The first electrode terminal is directly connected to the first tab, eliminating the need for a transition structure, simplifying the battery cell structure and improving energy density. The outer casing is highly rigid and less susceptible to damage when squeezed, protecting the electrode assembly and improving battery cell reliability.

[0010] In some embodiments, the first tab is welded to the first electrode terminal to reduce the contact resistance between the first tab and the first electrode terminal, improve the overcurrent capability, and increase the connection strength between the first tab and the first electrode terminal.

[0011] In some embodiments, the battery cell further includes an insulating member, at least a portion of which is disposed between the housing and the first electrode terminal and serves to insulate the housing from the first electrode terminal. The insulating member can reduce the risk of electrical conduction between the first electrode terminal and the housing, thereby improving the reliability of the battery cell.

[0012] In some embodiments, the insulating member is bonded to the outer shell and the first electrode terminal. The insulating member can secure the first electrode terminal to the outer shell, thereby improving the stability of the first electrode terminal and reducing the force at the connection between the first electrode terminal and the first tab when the battery cell is subjected to external impact, thereby reducing the risk of battery cell failure.

[0013] In some embodiments, at an ambient temperature of 25°C, the elastic modulus of the insulating member is less than the elastic modulus of the first electrode terminal. When the battery cell is subjected to an external impact, the insulating member can deform to provide a buffer, reducing the force applied to the connection between the first electrode terminal and the insulating member, as well as the force applied to the connection between the outer casing and the insulating member, thereby lowering the risk of connection failure and improving the reliability of the battery cell.

[0014] In some embodiments, the insulating member includes a first insulating layer and a second insulating layer stacked and extending along a first direction, and the first electrode terminal passes between the first insulating layer and the second insulating layer. In the first direction, the inner end of the first electrode terminal extends beyond the inner end of the second insulating layer, and the portion of the first electrode terminal extending beyond the second insulating layer is connected to the first tab. In the first direction, the inner end of the first insulating layer extends beyond the inner end of the first electrode terminal.

[0015] At least a portion of the first electrode terminal is not covered by the second insulating layer, facilitating connection between the first electrode terminal and the first tab. The inner end of the first insulating layer extends beyond the inner end of the first electrode terminal, so that the first insulating layer can insulate the first electrode terminal from the inner surface of the housing.

[0016] In some embodiments, the housing includes a first recess, the first recess being disposed outside the accommodating cavity. The first electrode terminal includes a first electrode portion located outside the housing, the first electrode portion being configured such that a projection along a second direction at least partially overlaps a projection along the second direction of the first recess, the second direction being perpendicular to the first direction.

[0017] In the embodiment of the present application, the first recess and the first electrode portion may share part of the space in the first direction, thereby increasing the space utilization of the battery cell in the first direction and improving the energy density of the battery cell.

[0018] In some embodiments, the first electrode portion extends from an end portion of the housing along the first direction, and at least a portion of the first electrode portion is accommodated in the first recess.

[0019] Accommodating at least part of the first electrode portion in the first recess can reduce the additional space occupied by the first electrode portion in the second direction, increase the space utilization of the battery cell in the second direction, and improve the energy density of the battery cell.

[0020] In some embodiments, the first electrode portion extends from an end portion of the housing along the first direction, and at least a portion of the first electrode portion is located on a side of the housing away from the first recess along the second direction.

[0021] When two battery cells are arranged along the second direction, the first recess of one battery cell can avoid the first electrode terminal of the other battery cell, thereby improving space utilization and enhancing the energy density of the battery.

[0022] In some embodiments, the housing includes a first wall and a second wall, the first wall and the second wall being located on either side of the accommodating cavity along a second direction, respectively; the first recess is recessed from the second wall toward the first wall; the first electrode terminal extends from the first wall along the second direction; and at least a portion of the first electrode portion is located on a side of the first wall facing away from the first recess.

[0023] When two battery cells are arranged along the second direction, the first recess of one battery cell can avoid the first electrode portion of the other battery cell, thereby improving space utilization and enhancing the energy density of the battery.

[0024] In some embodiments, the first electrode terminal further includes a second electrode portion and a third electrode portion, wherein the second electrode portion passes through the first wall, and the first electrode portion and the third electrode portion extend in the same direction from both ends of the second electrode portion. The third electrode portion is disposed in the accommodating cavity and is stacked and connected to the first tab in the second direction.

[0025] The second electrode portion and the third electrode portion are provided to facilitate connection between the first electrode terminal and the first tab. The first electrode portion and the third electrode portion extend in the same direction, allowing the first electrode portion and the third electrode portion to clamp a portion of the first wall from both sides, thereby improving the connection strength between the first electrode terminal and the first wall.

[0026] In some embodiments, the dimension L1 of the housing along the first direction is greater than the dimension L2 of the housing along the second direction. The dimension L1 of the housing along the first direction is greater than the dimension L3 of the housing along the third direction, and the third direction, the first direction, and the second direction are perpendicular to each other.

[0027] The first tab is positioned at the end of the electrode assembly along the first direction. A larger L1 indicates a smaller proportion of the first tab in the first direction, leading to higher space utilization of the battery cell in the first direction. In this embodiment, L1 is larger than L2, and L1 is larger than L3, thereby improving both space utilization and energy density of the battery cell.

[0028] In some embodiments, a dimension of the housing along the first direction is L1, a dimension of the housing along the second direction is L2, and a dimension of the housing along the third direction is L3. 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

[0029] The first tab is located at the end of the electrode assembly along the first direction, occupying additional space in the first direction. A larger L1 indicates a smaller proportion of the first tab in the first direction, resulting in higher space utilization for the battery cells in the first direction. A larger L2 indicates a larger flow area for the first tab, improving its flow capacity and reducing heat generation.

[0030] The smaller L3 is, the shorter the path for the electrode assembly to dissipate heat to the outside is, and the lower the temperature rise of the battery cell during charging and discharging is; however, the smaller L3 is, the thinner the battery cell is, and the battery cell is more likely to deform when subjected to external impact during production, transportation and use of the battery cell.

[0031] On the premise that the volume of the battery cell is certain, limiting L1 / L3 to 1.2-18 and limiting L3 / L2 to 1.2-15 can balance the space utilization of the battery cell in the first direction and the current carrying capacity of the first tab, reduce the temperature rise of the battery cell, reduce the risk of deformation of the battery cell when subjected to external impact, and improve the reliability and cycle performance of the battery cell.

[0032] In some embodiments, the housing includes a first wall and a second wall arranged opposite each other along a second direction, the second direction being perpendicular to the first direction and parallel to the thickness of the battery cell, and both the first wall and the second wall are flat. The second wall is provided with a pressure relief mechanism. In the event of thermal runaway of the battery cell, the pressure relief mechanism can promptly release high-temperature substances within the housing, thereby reducing the internal pressure of the battery cell, lowering the risk of battery cell explosion, and improving the reliability of the battery cell.

[0033] In some embodiments, the second wall has two edges disposed opposite to each other along the first direction, and the pressure relief mechanism and the two edges are spaced apart from each other by D1 and D2 in the first direction, respectively. D1 / D2 is 0.5-2.

[0034] The pressure relief structure is arranged near the middle of the second wall along the first direction. When thermal runaway occurs in the battery cell, the gas at both ends of the accommodating cavity along the first direction can flow quickly to the pressure relief mechanism, thereby reducing the pressure difference at both ends of the accommodating cavity and improving reliability.

[0035] In some embodiments, the housing is provided with a first through hole and a second through hole, the first through hole and the second through hole are respectively connected to two ends of the accommodating cavity along the first direction, and the first through hole and / or the second through hole are used for injecting electrolyte.

[0036] By providing the first through-hole and the second through-hole, the electrolyte injection pressure requirement can be reduced. For example, when the electrolyte is injected through the first through-hole, the gas inside the housing can be discharged through the second through-hole, thereby reducing the resistance to electrolyte injection, saving time, and improving the electrolyte's infiltration effect on the electrode assembly.

[0037] In some embodiments, the housing includes a first wall and a second wall, the first wall and the second wall being located on either side of the accommodating cavity along a second direction, the second direction being perpendicular to the first direction. The first through hole and the second through hole are both provided in the first wall; or, the first through hole and the second through hole are both provided in the second wall; or, the first through hole is provided in the first wall, and the second through hole is provided in the second wall.

[0038] In some embodiments, the housing includes a third wall and a fourth wall, the third wall and the fourth wall are respectively located at two ends of the accommodating cavity along the first direction. The third wall is provided with a first through hole, and the fourth wall is provided with a second through hole.

[0039] Providing the first through hole and the second through hole on the third wall and the fourth wall respectively can reduce the angle between the electrolyte injection direction and the first direction, thereby improving the injection efficiency.

[0040] In some embodiments, the electrode assembly includes a main body, the first electrode tab extends from the main body along a first direction and extends beyond the third wall, and in the first direction, the first through hole at least partially overlaps with the first electrode tab.

[0041] When the electrolyte is injected through the first through hole, the first electrode tab can block the electrolyte to a certain extent, thereby playing a buffering role, reducing the impact force of the electrolyte on the main body, reducing the risk of the isolation member of the main body being folded back, thereby reducing the risk of short circuit and improving reliability.

[0042] In some embodiments, the aperture of the first through hole is H1, the volume of the accommodating cavity is H2, and 100 ml / mm≤H2 / H1≤1000 ml / mm.

[0043] The smaller the ratio H2 / H1, the higher the electrolyte injection efficiency. Correspondingly, the smaller the ratio H2 / H1, the lower the strength around the first through-hole, increasing the risk of deformation and cracking of the outer shell at the first through-hole when the battery cell is subjected to external impact. In this embodiment, H2 / H1 is limited to 100ml / mm-1000ml / mm, which can improve electrolyte injection efficiency, reduce costs, and enhance battery cell reliability.

[0044] In some embodiments, the housing includes a shell and a cover. The shell includes a shell body and a first edge portion extending from a periphery of the shell body. The cover includes a cover body and a second edge portion extending from a periphery of the cover body. The shell body and the cover body define a receiving cavity, and the first edge portion and the second edge portion are connected to form a sealing structure. The provision of the first and second edge portions can enhance the connection strength between the shell and the cover, improving the sealing effect.

[0045] In some embodiments, at least a portion of the first edge portion is welded to the second edge portion to form a weld mark, and the sealing structure includes the weld mark. The welding process is simple and easy to implement. The weld mark has high strength and good sealing performance.

[0046] In some embodiments, the first electrode terminal passes between the first edge portion and the second edge portion. The battery cell further includes an insulating member, at least partially covering the portion of the first electrode terminal located between the first edge portion and the second edge portion, and bonded to the first edge portion and the second edge portion to insulate the first electrode terminal from the housing and from the cover plate. The insulating member and the sealing structure together seal the housing.

[0047] In some embodiments, at least a portion of the sealing structure is bent toward the shell body. By bending the sealing structure, the maximum size of the battery cell can be reduced and the energy density of the battery cell can be increased.

[0048] In some embodiments, at least a portion of the sealing structure is bent to a side of the cover body facing away from the shell body, which can reduce the size of the battery cell along the first direction or the size of the battery cell along the third direction.

[0049] In some embodiments, both the cover plate and the housing are made of aluminum. Aluminum has high strength and good thermal conductivity. Using an aluminum cover plate and housing can improve the cycling performance and reliability of the battery cells. Aluminum also has a low density. Using an aluminum cover plate and housing can also reduce the weight of the battery cells and increase their energy density.

[0050] In some embodiments, the hardness of the cover plate is in the range of 30HB-60HB. Under the premise that the hardness of the cover plate meets the requirements, the material of the cover plate can be flexibly set to reduce the weight and cost of the cover plate.

[0051] In some embodiments, the thickness of the cover plate is 0.02 mm-2 mm, which can balance the strength and weight of the cover plate, improve the reliability of the battery cell and increase the energy density of the battery cell.

[0052] In some embodiments, the hardness of the shell is in the range of 30HB-60HB. Setting the hardness of the shell to 30HB-60HB can facilitate the molding of the shell.

[0053] In some embodiments, the thickness of the shell is 0.02 mm-5 mm to balance the strength and weight of the shell, improve the reliability of the battery cell and increase the energy density of the battery cell.

[0054] In some embodiments, the electrode assembly further includes a second tab. The battery cell further includes a second electrode terminal, a portion of which is disposed in the accommodation cavity and connected to the second tab, and the second electrode terminal passes through the housing and extends outside the housing.

[0055] The second electrode terminal is directly connected to the second tab layer, which can omit the transition structure, thereby simplifying the structure of the battery cell and improving the energy density.

[0056] In some embodiments, the first electrode tab and the second electrode tab are respectively located at two ends of the electrode assembly along the first direction, so as to increase the distance between the first electrode tab and the second electrode tab and reduce the risk of short circuit between the first electrode tab and the second electrode tab.

[0057] In some embodiments, the first electrode tab and the second electrode tab are located at the same end of the electrode assembly along the first direction, so that the first electrode tab and the second electrode tab share space in the first direction, thereby improving space utilization of the battery cell in the first direction.

[0058] In a second aspect, the present application provides a battery comprising a plurality of battery cells provided by any embodiment of the first aspect.

[0059] In a third aspect, the present application provides an electrical device comprising a battery provided in any embodiment of the second aspect, the battery being used to provide electrical energy.

[0060] In a fourth aspect, an embodiment of the present application further provides a method for manufacturing a battery cell, which includes:

[0061] Providing an electrode assembly, wherein an end portion of the electrode assembly along a first direction is provided with a first electrode tab;

[0062] providing a first electrode terminal;

[0063] connecting the first tab and the first electrode terminal;

[0064] Providing a housing, and placing the electrode assembly in a receiving cavity of the housing;

[0065] The Brinell hardness of the shell is greater than or equal to 30HB, a portion of the first electrode terminal is disposed in the accommodating cavity, and the first electrode terminal passes through the shell and extends to the outside of the shell.

[0066] In some embodiments, the step of connecting the first electrode tab and the first electrode terminal includes welding the first electrode tab to the first electrode terminal.

[0067] In some embodiments, the steps of providing a housing and placing the electrode assembly in a receiving cavity of the housing include:

[0068] Providing a housing, the housing comprising a housing body and a first edge portion extending from a periphery of the housing body;

[0069] placing the electrode assembly into the shell body;

[0070] Providing a cover plate, the cover plate includes a cover body and a second edge portion extending from a periphery of the cover body;

[0071] Covering the housing with the cover plate to connect the first edge portion and the second edge portion to form a sealing structure;

[0072] The shell body and the cover body form a receiving cavity, and the first electrode terminal passes through between the first edge portion and the second edge portion.

[0073] In some embodiments, the step of connecting the first edge portion and the second edge portion to form a sealing structure includes connecting the first edge portion and the second edge portion by laser welding to form the sealing structure.

[0074] In some embodiments, the manufacturing method further includes: cutting the sealing structure; and bending the sealing structure toward the shell body. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0076] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0077] FIG2 is a schematic diagram of an explosion of a battery provided in some embodiments of the present application;

[0078] FIG3 is a schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0079] FIG4 is a schematic top view of a battery cell provided in some embodiments of the present application;

[0080] FIG5 is a schematic cross-sectional view of a battery cell provided in some embodiments of the present application;

[0081] FIG6 is an enlarged schematic diagram of the battery cell shown in FIG5 at the frame;

[0082] FIG7 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0083] FIG8 is an enlarged schematic diagram of the box in FIG7;

[0084] FIG9 is a partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application;

[0085] FIG10 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0086] FIG11 is an enlarged schematic diagram of the box in FIG10 ;

[0087] FIG12 is a schematic structural diagram of a battery cell provided in other embodiments of the present application;

[0088] FIG13 is a schematic cross-sectional view taken along the AA direction in FIG12;

[0089] FIG14 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0090] FIG15 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0091] FIG16 is a schematic structural diagram of a battery cell provided in some other embodiments of the present application;

[0092] FIG17 is a schematic structural diagram of an electrode assembly provided in some embodiments of the present application;

[0093] FIG18 is a schematic flow chart of a method for manufacturing a battery cell according to some embodiments of the present application.

[0094] In the accompanying drawings, the drawings are not necessarily drawn to scale.

[0095] The accompanying drawings are numbered as follows: 1. vehicle; 2. battery; 3. controller; 4. motor; 5. housing; 5a. first housing portion; 5b. second housing portion; 5c. storage space; 6. battery cell; 10. electrode assembly; 11. first electrode tab; 12. second electrode tab; 13. main body; 20. housing; 20a. storage cavity; 20b. first recess; 20c. first through hole; 20d. second through hole; 20e. second recess; 21. first wall; 22. second wall; 221. pressure relief mechanism; 23. third wall; 24. fourth wall; 25. housing; 251. housing body; 252. first edge portion; 26. cover plate; 261. cover body; 262. second edge portion; 27. sealing structure; 30. first electrode terminal; 31. first electrode portion; 32. second electrode portion; 33. third electrode portion; 40. Insulating member; 41. First insulating layer; 42. Second insulating layer; 50. Second electrode terminal; 60. First sealing member; X, first direction; Z, second direction; Y, third direction. DETAILED DESCRIPTION

[0096] Below, the embodiments of the battery cell, battery, and electrical device of the present application are described in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0097] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0098] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0099] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0100] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0101] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0102] In this application, the terms "plurality" and "multiple" refer to two or more.

[0103] Unless otherwise stated, the numerical values ​​of the various parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the examples of this application. Unless otherwise stated, the test temperature of each parameter is 25°C.

[0104] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0105] A battery cell typically includes an electrode assembly, which includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. For example, the electrode assembly also includes a separator disposed between the positive and negative electrodes. The separator can, to a certain extent, prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0106] Battery cells may include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0107] The battery cell may be a prismatic battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell or a polygonal battery. The polygonal battery may be, for example, a hexagonal battery.

[0108] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0109] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0110] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0111] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0112] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0113] Electrode assemblies typically have tabs, which are typically connected to the electrode terminals of a battery cell via a transition structure to conduct current out of the cell. However, the transition structure occupies space within the cell, affecting the energy density of the cell.

[0114] In view of this, an embodiment of the present application provides a battery cell that directly connects the tab and the electrode terminal, thereby eliminating the traditional adapter structure, increasing the space utilization inside the battery cell, and improving the energy density of the battery cell.

[0115] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0116] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0117] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0118] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application.

[0119] As shown in FIG1 , a battery 2 is provided inside the vehicle 1. The battery 2 may be provided at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1. For example, the battery 2 may serve as an operating power source for the vehicle 1.

[0120] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0121] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0122] FIG2 is a schematic diagram of an explosion of a battery provided in some embodiments of the present application.

[0123] As shown in FIG. 2 , the battery 2 includes a housing 5 and a battery cell 6 , and the battery cell 6 is accommodated in the housing 5 .

[0124] The housing 5 is used to accommodate the battery cells 6 and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other and together define a storage space 5c for accommodating the battery cells 6. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also both be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0125] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0126] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0127] In the battery 2, there can be one or more battery cells 6. If there are multiple battery cells 6, the multiple battery cells 6 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections within the multiple battery cells 6. The multiple battery cells 6 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 6 can be housed within the housing 5. Alternatively, multiple battery cells 6 can be first connected in series, in parallel, or in a hybrid connection to form a battery module, and then the multiple battery modules can be connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 5.

[0128] Figure 3 is a schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application; Figure 4 is a schematic diagram of a top view of a battery cell provided in some embodiments of the present application; Figure 5 is a schematic diagram of a cross-section of a battery cell provided in some embodiments of the present application; and Figure 6 is an enlarged schematic diagram of the battery cell shown in Figure 5 at the box.

[0129] 3 to 6 , an embodiment of the present application provides a battery cell 6 , which includes a housing 20 and an electrode assembly 10 . The housing 20 has a receiving cavity 20 a , and the electrode assembly 10 is disposed in the receiving cavity 20 a .

[0130] The electrode assembly 10 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 6, active ions (e.g., lithium ions) are intercalated and released between the positive and negative electrodes. Optionally, the electrode assembly 10 also includes a separator disposed between the positive and negative electrodes. The separator can reduce the risk of short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0131] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0132] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0133] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, silver surface treated aluminum or stainless steel, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0134] As an example, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active material layers may also be used. These positive electrode active material layers may use only one alone, or two or more may be used in combination. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0135] In some embodiments, the positive electrode may be a metal foam or a carbon foam. The metal foam may be nickel foam, copper foam, aluminum foam, or an alloy foam, among others. When the metal foam is used as the positive electrode, a positive electrode active material layer may or may not be provided on the surface of the metal foam. As an example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0136] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0137] As an example, the negative electrode current collector may be a metal foil, a metal foam, a carbon foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. may be used. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0138] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0139] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0140] As an example, the negative electrode active material may adopt the negative electrode active material for battery cell 6 that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0141] 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.

[0142] In some embodiments, the separator includes a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0143] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0144] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0145] The housing 20 is a hollow structure, and its interior forms a space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a rectangular parallelepiped structure, a rectangular housing can be selected.

[0146] The housing 20 can be made of a variety of materials, for example, metal or plastic. Alternatively, the housing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0147] In some embodiments, the battery cell 6 includes a housing 20, an electrode assembly 10, and a first electrode terminal 30. The housing 20 has a receiving cavity 20a. The electrode assembly 10 is disposed in the receiving cavity 20a. A first electrode tab 11 is provided at an end of the electrode assembly 10 along a first direction X. A portion of the first electrode terminal 30 is disposed within the receiving cavity 20a and connected to the first electrode tab 11. The first electrode terminal 30 passes through the housing 20 and extends outside the housing 20.

[0148] The electrode assembly 10 is a component where electrochemical reactions occur in the battery cell 6. The housing 20 may contain one or more electrode assemblies 10. The electrode assembly 10 may be a wound structure, a laminate structure, a wound laminate composite structure, or other structures.

[0149] The shape of the electrode assembly 10 can be cylindrical, flat, or polygonal.

[0150] As an example, the electrode assembly 10 includes a first electrode sheet, a second electrode sheet, and a separator. The polarity of the first electrode sheet is opposite to that of the second electrode sheet, and the separator is used to insulate the first electrode sheet from the second electrode sheet. The first electrode sheet includes a first current collector and a first active material layer coated on the surface of the first current collector. The second electrode sheet includes a second current collector and a second active material layer coated on the surface of the second current collector. The first electrode tab 11 includes a portion of the first current collector that is not coated with the first active material layer. One of the first and second electrode sheets is a positive electrode sheet, and the other is a negative electrode sheet.

[0151] The electrode assembly 10 may be provided with the first electrode tab 11 at only one end along the first direction X, or may be provided with the first electrode tab 11 at both ends along the first direction X.

[0152] For example, the first electrode terminal 30 may be used to electrically connect the electrode assembly 10 to the current outside the battery cell 6 , thereby enabling charging and discharging of the battery cell 6 .

[0153] The first electrode terminal 30 is directly connected to the first electrode tab 11 , which can omit the transition structure, thereby simplifying the structure of the battery cell 6 and improving the energy density.

[0154] In some embodiments, the Brinell hardness of the housing 20 is greater than or equal to 30 HB.

[0155] For example, the Brinell hardness of the housing 20 may be measured in accordance with the method specified in GBT231-1984-Metal Brinell Hardness Test Method.

[0156] Optionally, the hardness of the shell 20 is greater than or equal to 30HB, that is, the hardness value measured by a quenched steel ball indenter is greater than or equal to 30.

[0157] The outer shell 20 has a relatively high hardness and is not easily crushed when squeezed, thereby protecting the electrode assembly 10 and improving the reliability of the battery cell 6. For example, compared to battery cells using aluminum-plastic film outer shells, the outer shell 20 of the battery cell of the present application has a higher hardness, is less likely to be crushed, and has better reliability.

[0158] In addition, the housing 20 of the embodiment of the present application has a relatively high hardness, which can reduce the thickness requirement of the housing 20 and improve the energy density of the battery cell.

[0159] In some embodiments, the hardness of the shell 20 is 30HB-600HB, optionally 30HB, 35HB, 40HB, 45HB, 50HB, 55HB, 60HB, 80HB, 100HB, 150HB, 200HB, 250HB, 300HB, 350HB, 400HB, 450HB, 500HB, 550HB or 600HB.

[0160] In some embodiments, the hardness of the shell 20 is 30HB-300HB; optionally, the hardness of the shell 20 is 30HB-60HB.

[0161] In some embodiments, the first electrode terminal 30 and the first electrode tab 11 are stacked and connected in the second direction Z, where the first direction X intersects the second direction Z. Stacking and connecting the first electrode terminal 30 and the first electrode tab 11 allows the first electrode terminal 30 and the first electrode tab 11 to share a portion of space in the first direction X, thereby increasing space utilization in the first direction X and improving the energy density of the battery cell 6. Furthermore, stacking the first electrode terminal 30 and the first electrode tab 11 can increase the connection area between the two.

[0162] In some embodiments, the second direction Z is perpendicular to the first direction X. It can be understood that “perpendicular” includes not only an absolutely perpendicular situation, but also a substantially perpendicular situation conventionally recognized in engineering.

[0163] In some embodiments, the first electrode terminal 30 is an integral structure.

[0164] In some embodiments, the first electrode terminal 30 is a sheet-like structure. This structure can reduce the volume of the first electrode terminal 30 and increase the contact area between the first electrode terminal 30 and the first tab 11, thereby improving the connection strength and flow area between the first electrode terminal 30 and the first tab 11.

[0165] In some embodiments, after the first electrode terminal 30 is flattened, the first electrode terminal 30 has a thickness of 0.05 mm to 15 mm, a width of 5 mm to 100 mm, and a length of 10 mm to 100 mm.

[0166] Optionally, the thickness of the first electrode terminal 30 is 0.5 mm to 5 mm. Optionally, the width of the first electrode terminal 30 is 10 mm to 40 mm. Optionally, the length of the first electrode terminal 30 is 20 mm to 60 mm.

[0167] In some embodiments, the housing 20 includes a shell 25 and a cover 26 . The shell 25 has an opening, and the cover 26 is used to cover the opening.

[0168] The housing 25 is a component used to cooperate with the cover plate 26 to form a receiving cavity 20 a for the battery cell 6 . The formed receiving cavity 20 a can be used to accommodate the electrode assembly 10 , electrolyte, and other components.

[0169] The housing 25 and the cover plate 26 may be separate components. For example, an opening may be provided on the housing 25 , and the cover plate 26 may cover the opening to form an internal cavity of the battery cell 6 .

[0170] The housing 25 can be of various shapes and sizes, such as a rectangular parallelepiped, a hexagonal prism, etc. Specifically, the shape of the housing 25 can be determined according to the specific shape and size of the electrode assembly 10. The housing 25 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0171] The shape of the cover plate 26 can be adapted to the shape of the housing 25 to fit the housing 25. The material of the cover plate 26 can be the same as or different from the material of the housing 25. Optionally, the cover plate 26 can be made of a material with a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). In this way, the cover plate 26 is less likely to deform when subjected to compression or collision, thereby providing the battery cell 6 with higher structural strength and improved reliability.

[0172] The cover plate 26 can be connected to the housing 25 by welding, bonding, clamping or other methods.

[0173] The first electrode terminal 30 may pass through the housing 25 , may pass through the cover plate 26 , or may pass between the housing 25 and the cover plate 26 .

[0174] In some embodiments, the cover plate 26 is made of metal. Metal has high hardness and can effectively protect the electrode assembly 10 from the outside. Exemplarily, the cover plate 26 is made of aluminum or an aluminum alloy.

[0175] In some embodiments, the housing 25 is made of metal. For example, the housing 25 is made of aluminum or aluminum alloy.

[0176] In some embodiments, the cover plate 26 and the housing 25 are made of the same material.

[0177] Metal materials have high strength and good thermal conductivity. Using metal cover plate 26 and housing 25 can improve the cycle performance of battery cell 6 and enhance the reliability of battery cell 6.

[0178] In some embodiments, the cover plate 26 and the housing 25 are both made of aluminum. Aluminum has high strength and good thermal conductivity. Using an aluminum cover plate 26 and housing 25 can improve the cycle performance of the battery cell 6 and enhance the reliability of the battery cell 6. Aluminum has a low density. Using an aluminum cover plate 26 and housing 25 can also reduce the weight of the battery cell 6 and increase the energy density of the battery cell 6.

[0179] In some embodiments, the cover plate 26 and the housing 25 are connected by welding. Alternatively, the cover plate 26 and the housing 25 are connected by laser welding or ultrasonic welding. Further, optionally, the laser welding is non-penetrating laser welding.

[0180] In some embodiments, the hardness of the cover plate 26 ranges from 30 HB to 60 HB. Under the premise that the hardness of the cover plate 26 meets the requirements, the material of the cover plate 26 can be flexibly set to reduce the weight and cost of the cover plate 26.

[0181] In some embodiments, the hardness of the housing 25 ranges from 30HB to 60HB. As long as the hardness of the housing 25 meets the requirements, the material of the housing 25 can be flexibly adjusted to reduce the weight and cost of the housing 25. Setting the hardness of the housing 25 to 30HB to 60HB facilitates the molding of the housing 25.

[0182] In some embodiments, the thickness of the housing 25 is 0.02 mm to 5 mm. Optionally, the thickness of the housing 25 is 0.1 mm to 0.8 mm to balance the strength and weight of the housing 25 , improve the reliability of the battery cell 6 , and increase the energy density of the battery cell 6 .

[0183] In some embodiments, the thickness of the cover plate 26 is 0.02 mm to 2 mm. Optionally, the thickness of the cover plate 26 is 0.08 mm to 0.5 mm to balance the strength and weight of the cover plate 26 , improve the reliability of the battery cell 6 , and increase the energy density of the battery cell 6 .

[0184] In some embodiments, the first electrode tab 11 is welded to the first electrode terminal 30 to reduce the contact resistance between the first electrode tab 11 and the first electrode terminal 30 , improve the overcurrent capacity, and increase the connection strength between the first electrode tab 11 and the first electrode terminal 30 .

[0185] In some embodiments, the first electrode tab 11 is connected to the first electrode terminal 30 by ultrasonic welding.

[0186] In some embodiments, the first electrode tab 11 includes a plurality of electrode tab layers, which are stacked on the first electrode terminal 30 and welded to the first electrode terminal 30 .

[0187] In some embodiments, the electrode assembly 10 is a laminated structure.

[0188] In some embodiments, the electrode assembly 10 includes a plurality of first electrode sheets and a plurality of second electrode sheets, wherein the polarity of the first electrode sheets is opposite to that of the second electrode sheets, and the plurality of first electrode sheets and the plurality of second electrode sheets are alternately stacked along the second direction Z. The electrode assembly 10 adopts a laminated structure, which can improve space utilization and increase the energy density of the battery cell 6.

[0189] In some embodiments, the battery cell 6 further includes an insulating member 40 . At least a portion of the insulating member 40 is disposed between the outer shell 20 and the first electrode terminal 30 and is used to insulate the outer shell 20 from the first electrode terminal 30 .

[0190] The insulating member 40 can reduce the risk of electrical conduction between the first electrode terminal 30 and the housing 20 , thereby improving the reliability of the battery cell 6 .

[0191] In some embodiments, in the second direction Z, a projection of the first electrode tab 11 at least partially overlaps with a projection of the insulating member 40 ; the insulating member 40 can insulate at least a portion of the first electrode tab 11 from the housing 20 .

[0192] In some embodiments, the insulating member 40 is bonded to the outer shell 20 and the first electrode terminal 30. The insulating member 40 can fix the first electrode terminal 30 to the outer shell 20, thereby improving the stability of the first electrode terminal 30, reducing the force at the connection between the first electrode terminal 30 and the first tab 11 when the battery cell 6 is subjected to an external impact, and reducing the risk of failure of the battery cell 6.

[0193] In some embodiments, the material of the insulating member 40 includes but is not limited to at least one of polypropylene (PP), polyethylene (PE), or polyvinyl chloride (PVC).

[0194] In some embodiments, the insulating member 40 is bonded to the housing 20 and the first electrode terminal 30 via an adhesive layer. Optionally, the adhesive layer comprises AB glue (two-liquid mixed curing glue); further optionally, the AB glue comprises epoxy resin and a curing agent.

[0195] In some embodiments, the insulating member 40 is connected to the first electrode terminal 30 and the housing 25 by a thermal compression lamination process. The thermal compression lamination process is simple and easily connects the insulating member 40 to the housing 20 and the first electrode terminal 30. It can also improve the bonding strength of the composite interface between the insulating member 40 and the housing 20 and the composite interface between the insulating member 40 and the first electrode terminal 30, thereby improving the reliability of the battery cell 6.

[0196] Exemplarily, a passivation film is provided on the surface of the first electrode terminal 30 , and the passivation film is connected to the insulating member 40 .

[0197] Exemplarily, a passivation film is provided on the surface of the housing 20 , and the passivation film is connected to the insulating member 40 .

[0198] In some embodiments, at an ambient temperature of 25°C, the elastic modulus of the insulating member 40 is less than the elastic modulus of the first electrode terminal 30. When the battery cell 6 is subjected to an external impact, the insulating member 40 can deform to act as a buffer, reducing the force at the connection between the first electrode terminal 30 and the insulating member 40 and the force at the connection between the housing 20 and the insulating member 40, thereby reducing the risk of connection failure and improving the reliability of the battery cell 6.

[0199] In some embodiments, at least a portion of the insulating member 40 is disposed around the first electrode terminal 30 to insulate the first electrode terminal 30 from the housing 20 .

[0200] In some embodiments, the insulating member 40 includes a first insulating layer 41 and a second insulating layer 42 that are stacked, and the first electrode terminal 30 passes through between the first insulating layer 41 and the second insulating layer 42 .

[0201] In some embodiments, the first insulating layer 41 and the second insulating layer 42 extend along the first direction X.

[0202] In some embodiments, in the first direction X, the inner end E2 of the first electrode terminal extends beyond the inner end E1 of the second insulating layer, and a portion of the first electrode terminal 30 extending beyond the second insulating layer 42 is connected to the first tab 11 .

[0203] The inner end E2 of the first electrode terminal and the inner end E1 of the second insulating layer are staggered in the first direction X, so that at least a portion of the first electrode terminal 30 is not covered by the second insulating layer 42 , thereby facilitating the connection between the first electrode terminal 30 and the first tab 11 .

[0204] In some embodiments, an inner end E3 of the first insulating layer exceeds an inner end E2 of the first electrode terminal in the first direction X. The first insulating layer 41 may insulate the first electrode terminal 30 from an inner surface of the outer case.

[0205] In some embodiments, in the first direction X, a size of the first insulating layer 41 is greater than a size of the second insulating layer 42 .

[0206] In some embodiments, in the first direction X, an outer end of the first insulating layer 41 is flush with an outer end of the second insulating layer 42 .

[0207] In some embodiments, both ends of the first insulating layer 41 extend beyond the first electrode terminal 30 in the third direction Y, and both ends of the second insulating layer 42 extend beyond the first electrode terminal 30. The portion of the first insulating layer 41 extending beyond the first electrode terminal 30 in the third direction Y is connected to the second insulating layer 42.

[0208] In some embodiments, the first insulating layer 41 , the first tab 11 , and the first electrode terminal 30 overlap in the second direction Z. In the overlapping region, two surfaces of the first electrode terminal 30 are connected to the first insulating layer 41 and the first tab 11 , respectively.

[0209] In some embodiments, the electrode assembly 10 further includes a main body 13 , and the first electrode tab 11 extends from an end portion of the main body 13 along the first direction X.

[0210] The first electrode tab 11 extends from one end of the main body 13 along the first direction X. Alternatively, there may be two first electrode tabs 11 , which extend from both ends of the main body 13 along the first direction X respectively.

[0211] The main body 13 includes a portion of the first current collector coated with the first active material layer, a portion of the second current collector coated with the second active material layer, the first active material layer, and the second active material layer.

[0212] In some embodiments, in the first direction X, the inner end E3 of the first insulating layer is closer to the main body 13 than the inner end E1 of the second insulating layer.

[0213] In some embodiments, the electrode assembly 10 further includes a second electrode tab 12 , and the first electrode tab 11 and the second electrode tab 12 have opposite polarities.

[0214] Illustratively, the second electrode tab 12 includes a portion of the second current collector that is not coated with the second active material layer.

[0215] The first electrode tab 11 and the second electrode tab 12 may be located at two ends of the electrode assembly 10 along the first direction X, or may be located at the same end of the electrode assembly 10 along the first direction X.

[0216] In some embodiments, the first electrode tab 11 and the second electrode tab 12 may be located at both ends of the electrode assembly 10 along the first direction X, respectively, to increase the distance between the first electrode tab 11 and the second electrode tab 12 and reduce the risk of short circuit between the first electrode tab 11 and the second electrode tab 12 .

[0217] The first electrode tab 11 and the second electrode tab 12 extend from both ends of the main body 13 along the first direction X, respectively, and the two can share space in the third direction Y. Therefore, the first electrode tab 11 and the second electrode tab 12 can have a larger size in the third direction Y, thereby improving the current flow capacity and reducing the temperature rise of the first electrode tab 11 and the second electrode tab 12.

[0218] In some embodiments, the battery cell 6 further includes a second electrode terminal 50 , a portion of which is disposed in the accommodating cavity 20 a and connected to the second electrode tab 12 , and the second electrode terminal 50 passes through the housing 20 and extends to the outside of the housing 20 .

[0219] The second electrode terminal 50 is directly connected to the second electrode tab 12 , which can omit the transition structure, thereby simplifying the structure of the battery cell 6 and improving the energy density.

[0220] In some embodiments, the second electrode terminal 50 and the second electrode tab 12 are stacked and connected in the second direction Z. The second electrode terminal 50 is connected to the second electrode tab 12 so that the second electrode terminal 50 and the second electrode tab 12 share a portion of space in the first direction X, thereby increasing space utilization in the first direction X and improving the energy density of the battery cell 6.

[0221] In some embodiments, the second electrode terminal 50 is welded to the second electrode tab 12 .

[0222] In some embodiments, the dimension L1 of the housing 20 along the first direction X is greater than the dimension L2 of the housing 20 along the second direction Z. The dimension L1 of the housing 20 along the first direction X is greater than the dimension L3 of the housing 20 along the third direction Y. The third direction Y, the first direction X, and the second direction Z are perpendicular to each other.

[0223] The first electrode tab 11 is disposed at the end of the electrode assembly 10 along the first direction X. The larger L1 is, the smaller the proportion of the first electrode tab 11 in the first direction X is, and the higher the space utilization of the battery cell 6 in the first direction X. In the embodiment of the present application, L1 is greater than L2, and L1 is greater than L3, which can improve the space utilization and energy density of the battery cell 6.

[0224] In some embodiments, the size of the housing 20 along the first direction X is L1, the size of the housing 20 along the second direction Z is L2, and the size of the housing 20 along the third direction Y is L3. 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

[0225] Exemplarily, the first direction X is the length direction of the battery cell 6 , the second direction Z is the thickness direction of the battery cell 6 , and the third direction Y is the width direction of the battery cell 6 .

[0226] For example, L1 may be the maximum dimension of the housing 20 along the first direction X, L2 may be the maximum dimension of the housing 20 along the second direction Z, and L3 may be the maximum dimension of the housing 20 along the third direction Y.

[0227] The first electrode tab 11 is disposed at the end of the electrode assembly 10 along the first direction X, occupying additional space in the first direction X. The larger L1 is, the smaller the size of the first electrode tab 11 in the first direction X is, and the higher the space utilization of the battery cell 6 in the first direction X is. The larger L2 is, the larger the flow area of ​​the first electrode tab 11 is, the better the flow capacity of the first electrode tab 11 is, and the lower the heat generation is.

[0228] The smaller L3 is, the shorter the path for the electrode assembly 10 to dissipate heat to the outside is, and the lower the temperature rise of the battery cell 6 during charging and discharging is; however, the smaller L3 is, the thinner the battery cell 6 is, and the battery cell 6 is more likely to deform when subjected to external impact during the production, transportation and use of the battery cell 6.

[0229] On the premise that the volume of the battery cell 6 is certain, L1 / L3 is limited to 1.2-18 and L3 / L2 is limited to 1.2-15. This can balance the space utilization of the battery cell 6 in the first direction X and the current carrying capacity of the first pole ear 11, reduce the temperature rise of the battery cell 6, reduce the risk of deformation of the battery cell 6 when subjected to external impact, and improve the reliability and cycle performance of the battery cell 6.

[0230] Alternatively, L1 / L3 may be 1.2, 2, 3, 4, 5, 7, 8, 10, 12, 14, 15, 17 or 18.

[0231] Alternatively, L3 / L2 may be 1.2, 2, 3, 4, 5, 7, 8, 10, 12, 14 or 15.

[0232] In some embodiments, L1 / L3 is 3-7. L3 / L2 is 2-7.

[0233] In some embodiments, L1 is 10 mm to 3000 mm. Alternatively, L1 is 100 mm to 1500 mm.

[0234] Optionally, L1 is 10 mm, 50 mm, 100 mm, 300 mm, 400 mm, 500 mm, 600 mm, 1000 mm, 1200 mm, 1500 mm, 2000 mm, 2500 mm or 3000 mm.

[0235] In some embodiments, L3 is 10 mm to 3000 mm. Alternatively, L3 is 80 mm to 1000 mm.

[0236] Optionally, L3 is 10 mm, 80 mm, 100 mm, 300 mm, 400 mm, 500 mm, 600 mm, 1000 mm, 1200 mm, 1500 mm, 2000 mm, 2500 mm or 3000 mm.

[0237] In some embodiments, L2 is 5 mm to 1000 mm. Alternatively, L2 is 10 mm to 300 mm.

[0238] Optionally, L32 is 5mm, 10mm, 30mm, 50mm, 60mm, 80mm, 100mm, 200mm, 300mm, 500mm, 600mm, 800mm or 1000mm.

[0239] In some embodiments, the housing 20 is provided with a pressure relief mechanism 221 .

[0240] There can be one or more pressure relief mechanisms 221 .

[0241] The pressure relief mechanism 221 significantly impacts the reliability of the battery cell 6. For example, short circuits, overcharging, and other conditions can cause thermal runaway within the battery cell 6, leading to a sudden increase in pressure. In this situation, the pressure relief mechanism 221 is activated to release the internal pressure, preventing the battery cell 6 from exploding or catching fire.

[0242] The pressure relief mechanism 221 is a component or element that is activated to release the internal pressure of the battery cell 6 when the internal pressure reaches a predetermined threshold. This threshold varies depending on the design requirements. This threshold may depend on the materials of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 6.

[0243] The pressure relief mechanism 221 may be provided on the cover plate 26 or on the housing 25 .

[0244] In some embodiments, the housing 20 includes a first wall 21 and a second wall 22 , which are disposed opposite to each other along the second direction Z. Exemplarily, the first wall 21 and the second wall 22 are located on both sides of the accommodating cavity 20 a along the second direction Z, respectively.

[0245] The first wall 21 and the second wall 22 are walls of the housing 20 having a certain thickness. In some examples, the cover 26 includes the first wall 21, and the housing 25 includes the second wall 22. Alternatively, the cover 26 includes the second wall 22, and the housing 25 includes the first wall 21.

[0246] For example, the area of ​​the second wall 22 may be greater than, equal to, or smaller than the area of ​​the first wall 21. For example, the second wall 22 may have the same shape and size as the first wall 21. Alternatively, the area of ​​the second wall 22 may be smaller than the area of ​​the first wall 21.

[0247] In the second direction Z, the main body 13 may be disposed between the first wall 21 and the second wall 22 .

[0248] In some embodiments, the first wall 21 and the second wall 22 are both flat walls.

[0249] In some embodiments, the second direction Z is perpendicular to the first direction X and parallel to the thickness direction of the battery cell. Exemplarily, the second direction Z is perpendicular to the first wall 21 and the second wall 22 .

[0250] In some embodiments, the second wall 22 is provided with a pressure relief mechanism 221 .

[0251] In some examples, the second wall 22 and the pressure relief mechanism 221 may be integrally formed. In alternative examples, the pressure relief mechanism 221 and the second wall 22 may be independently formed components, connected by welding, bonding, or other means. For example, the second wall 22 may be provided with a pressure relief hole that extends through the second wall 22. The pressure relief mechanism 221 may be mounted on the second wall 22 and cover the pressure relief hole, thereby separating the inner and outer spaces of the second wall 22.

[0252] When thermal runaway occurs in the battery cell 6 , the pressure relief mechanism 221 can timely release the high-temperature material in the housing 20 , thereby reducing the internal pressure of the battery cell 6 , lowering the risk of explosion of the battery cell 6 , and improving the reliability of the battery cell 6 .

[0253] In some embodiments, the second wall 22 is integrally formed with the pressure relief mechanism 221 , and the pressure relief mechanism 221 includes a weakened portion.

[0254] The strength of the weak portion is lower than that of other portions of the second wall 22 , and the weak portion is a portion that is easily broken, shattered, torn, or opened.

[0255] In some examples, grooves, notches, or other structures may be provided in predetermined regions of the second wall 22 to reduce the local strength of the second wall 22, thereby forming a weak portion in the second wall 22. For example, a predetermined region of the second wall 22 may be thinned, and the thinned portion of the second wall 22 may form the weak portion. In other examples, a material treatment may be performed on the predetermined region of the second wall 22 to make the region weaker than other regions. In other words, this region may serve as the weak portion.

[0256] The second wall 22 and the pressure relief mechanism 221 are formed integrally, which not only saves the process of connecting the second wall 22 and the pressure relief mechanism 221 , but also improves the connection strength between the second wall 22 and the pressure relief mechanism 221 .

[0257] In some embodiments, the second wall 22 has two edges disposed opposite to each other along the first direction X. The pressure relief mechanism 221 is spaced apart from the two edges by distances D1 and D2 in the first direction X. D1 / D2 is 0.5-2.

[0258] For example, D1 may be the minimum distance between the pressure relief mechanism 221 and one edge in the first direction X, and D2 may be the minimum distance between the pressure relief mechanism 221 and another edge in the first direction X.

[0259] The pressure relief mechanism 221 of the embodiment of the present application is arranged near the middle of the second wall 22 along the first direction X. When the battery cell 6 has thermal runaway, the gas at both ends of the accommodating cavity 20a along the first direction X can quickly flow to the pressure relief mechanism 221, thereby reducing the pressure difference at both ends of the accommodating cavity 20a and improving reliability.

[0260] Optionally, D1 / D2 is 0.5, 0.8, 1, 1.2, 1.5, 1.8 or 2.

[0261] Optionally, D1 / D2 is 0.8-1.2, and further optionally, D1 / D2 is 1. The geometric center of the pressure relief mechanism 221 coincides with the geometric center of the second wall 22 .

[0262] In some embodiments, the pressure relief mechanism 221 may be a circular structure, an elliptical structure, or a racetrack structure.

[0263] In some embodiments, the diameter of the pressure relief mechanism 221 is 10 mm to 50 mm. Alternatively, the diameter of the pressure relief mechanism 221 is 20 mm to 30 mm.

[0264] In some embodiments, the housing 20 is provided with a first through hole 20 c and a second through hole 20 d , which are respectively connected to two ends of the accommodating cavity 20 a along the first direction X. The first through hole 20 c is used for injecting electrolyte.

[0265] For example, during the production process of the battery cell 6 , electrolyte may be injected into the housing 20 through the first through hole 20 c.

[0266] There may be one or more first through holes 20c.

[0267] The first through hole 20c and the second through hole 20d can be provided in the same wall of the housing 20, or respectively provided in two walls of the housing 20. For example, the first through hole 20c and the second through hole 20d can be both provided in the first wall 21, both provided in the second wall 22, or respectively provided in the first wall 21 and the second wall 22.

[0268] By providing the first through hole 20c and the second through hole 20d, the requirement for electrolyte injection pressure can be reduced. When the electrolyte is injected through the first through hole 20c, the gas inside the housing 20 can be discharged through the second through hole 20d, thereby reducing the resistance to electrolyte injection, saving time, and improving the electrolyte infiltration effect on the electrode assembly 10.

[0269] In addition, by providing the first through hole 20c and the second through hole 20d at the same time, the traditional vacuuming process can be omitted, thereby saving processes and reducing costs.

[0270] In some embodiments, the housing 20 is provided with a first through hole 20 c and a second through hole 20 d , which are respectively connected to the two ends of the accommodating cavity 20 a along the first direction X. The second through hole 20 d is used for injecting electrolyte. For example, when injecting electrolyte, the first through hole 20 c can serve as a gas exhaust channel.

[0271] In some embodiments, the housing 20 is provided with a first through hole 20 c and a second through hole 20 d , which are respectively connected to the two ends of the accommodating cavity 20 a along the first direction X. The first through hole 20 c and the second through hole 20 d are used to inject electrolyte. Simultaneously injecting electrolyte from both sides can improve injection efficiency.

[0272] In some embodiments, the first through hole 20 c and the second through hole 20 d are arranged diagonally to each other, which can improve the wetting effect of the electrolyte on the electrode assembly 10 .

[0273] In some embodiments, the first through hole 20c is circular, and the diameter of the first through hole 20c is 0.5 mm to 20 mm. Optionally, the diameter of the first through hole 20c is 3 mm to 10 mm.

[0274] In some embodiments, the second through hole 20d is circular, and the diameter of the second through hole 20d is 0.5 mm to 20 mm. Optionally, the diameter of the second through hole 20d is 3 mm to 10 mm.

[0275] In some embodiments, the aperture of the second through hole 20 d may be smaller than or equal to the aperture of the first through hole 20 c .

[0276] For example, for a non-circular hole, the minimum cross-sectional area (i.e., the area of ​​the minimum cross-sectional area perpendicular to the axial direction of the hole) is S; then the aperture of the non-circular hole is:

[0277] In some embodiments, the housing 20 includes a third wall 23 and a fourth wall 24 , which are respectively located at two ends of the accommodating cavity 20 a along the first direction X. The third wall 23 defines a first through hole 20 c , and the fourth wall 24 defines a second through hole 20 d .

[0278] The first through hole 20 c and the second through hole 20 d are respectively provided on the third wall 23 and the fourth wall 24 , so as to reduce the angle between the electrolyte injection direction and the first direction X and improve the injection efficiency.

[0279] In some embodiments, the electrode assembly 10 includes a main body 13 , and the first electrode tab 11 extends from the main body 13 along the first direction X and beyond the third wall 23 . In the first direction X, the first through hole 20 c at least partially overlaps with the first electrode tab 11 .

[0280] When the electrolyte is injected through the first through hole 20c, the first electrode tab 11 can block the electrolyte to a certain extent, thereby playing a buffering role, reducing the impact force of the electrolyte on the main body 13, reducing the risk of the isolation member of the main body 13 being folded back, thereby reducing the risk of short circuit and improving reliability.

[0281] In some embodiments, the aperture of the first through hole 20 c is H1 , the volume of the accommodating cavity 20 a is H2 , and 100 ml / mm≤H2 / H1≤1000 ml / mm.

[0282] For example, the first through hole 20c may be a hole of constant diameter or a hole of variable diameter. In the case where the first through hole 20c is a hole of variable diameter, H1 is the minimum hole diameter of the first through hole 20c.

[0283] For example, for a non-circular first through hole 20c, the minimum cross-sectional area of ​​the first through hole 20c (i.e., the area of ​​the minimum cross-sectional area perpendicular to the axial direction of the first through hole 20c) is S1; then the aperture of the first through hole 20c is:

[0284] For example, the volume H2 of the accommodating chamber 20a is tested as follows: Under a stable environment at 25°C, a solvent is injected into the accommodating chamber 20a (the accommodating chamber 20a does not contain any other components, such as an electrode assembly) through the first through-hole 20c until the accommodating chamber 20a is completely filled. The weight of the housing 20 is G1; after the accommodating chamber 20a is filled with the solvent, the total weight of the housing 20 and the solvent is G2; the density of the solvent is ρ. The volume H2 of the accommodating chamber 20a = (G2 - G1) / ρ.

[0285] The smaller the ratio H2 / H1, the higher the electrolyte injection efficiency. Correspondingly, the smaller the ratio H2 / H1, the lower the strength around the first through-hole 20c, increasing the risk of deformation or cracking of the housing 20 at the first through-hole 20c when the battery cell 6 is subjected to external impact. In this embodiment, H2 / H1 is limited to 100ml / mm-1000ml / mm, which can improve electrolyte injection efficiency, reduce costs, and enhance the reliability of the battery cell 6.

[0286] Optionally, H2 / H1 is 100 ml / mm, 200 ml / mm, 300 ml / mm, 400 ml / mm, 500 ml / mm, 600 ml / mm, 700 ml / mm, 800 ml / mm, 900 ml / mm or 1000 ml / mm.

[0287] In some embodiments, the battery cell 6 includes a first sealing member 60 for sealing the first through hole 20 c. Exemplarily, the first sealing member 60 is connected to the housing 20 .

[0288] In some embodiments, the battery cell 6 includes a second sealing member (not shown) for sealing the second through hole 20 d .

[0289] FIG7 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application; FIG8 is an enlarged schematic view of the frame in FIG7 .

[0290] As shown in FIG. 7 , in some embodiments, the housing 20 is provided with a first recess 20 b , and the first recess 20 b is provided outside the accommodating cavity 20 a .

[0291] The first electrode terminal 30 includes a first electrode portion 31 located outside the housing 20 . The projection of the first electrode portion 31 along the second direction Z at least partially overlaps with the projection of the first recess 20 b along the second direction Z.

[0292] In some examples, the first electrode portion 31 can extend into the first recess 20b so that the first electrode portion 31 overlaps with the first recess 20b along the second direction Z; in other examples, the first electrode portion 31 can also extend to the side of the housing 20 away from the first recess 20b so that the first electrode portion 31 overlaps with the first recess 20b along the second direction Z.

[0293] In the embodiment of the present application, the first recess 20 b and the first electrode portion 31 may share a portion of the space in the first direction X, thereby increasing the space utilization of the battery cell 6 in the first direction X and improving the energy density of the battery cell 6 .

[0294] In some embodiments, the first electrode terminal 30 passes through the outer shell 20 and extends to the outside of the outer shell 20. The projection of the extended end of the first electrode terminal 30 along the second direction Z is located within the projection of the first recess 20b along the second direction Z.

[0295] In some embodiments, the first recess 20 b is recessed from the second wall 22 toward the first wall 21 .

[0296] In some embodiments, the first electrode portion 31 extends from an end portion of the housing 20 along the first direction X. At least a portion of the first electrode portion 31 is received in the first recess 20 b.

[0297] Accommodating at least a portion of the first electrode portion 31 in the first recess 20 b can reduce the additional space occupied by the first electrode portion 31 in the second direction Z, increase the space utilization of the battery cell 6 in the second direction Z, and improve the energy density of the battery cell 6 .

[0298] In some embodiments, the first electrode terminal 30 passes between the cover plate 26 and the housing 25 and is bent back so that the outer end of the first electrode terminal 30 extends into the first recess 20 b.

[0299] Exemplarily, the first electrode terminal 30 is bent into a C-shaped structure.

[0300] In some embodiments, the first electrode portion 31 is spaced apart from the bottom wall of the first recess 20 b , and the first electrode portion 31 is spaced apart from the side wall of the first recess 20 b , thereby reducing the risk of short circuit.

[0301] In some embodiments, an insulating layer (not shown) is provided on the bottom wall of the first recess 20b and the side walls of the first recess 20b. Optionally, the insulating layer is bonded to the bottom wall of the first recess 20b and the side walls of the first recess 20b.

[0302] In some embodiments, the first through hole 20c may be disposed on a side wall of the first recess 20b or a bottom wall of the first recess 20b.

[0303] In some embodiments, the third wall 23 is a special-shaped wall, which includes a bottom wall of the first recess 20b and side walls of the first recess 20b.

[0304] In some embodiments, the housing 20 is provided with a second recess 20 e , which is recessed relative to a surface of the second wall 22 facing away from the first wall 21 .

[0305] Exemplarily, the first recess 20 b and the second recess 20 e are respectively located on both sides of the second wall 22 along the first direction X.

[0306] In some embodiments, a portion of the second electrode terminal 50 located outside the outer housing 20 extends into the second recess 20 e .

[0307] Exemplarily, the second electrode terminal 50 is bent into a C-shaped structure.

[0308] FIG9 is a schematic partial cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0309] 9 , in some embodiments, the first electrode portion 31 extends from an end of the housing 20 along the first direction X. At least a portion of the first electrode portion 31 is located along the second direction Z on a side of the housing 20 away from the first recess 20 b.

[0310] Exemplarily, at least a portion of the first electrode portion 31 is located on a side of the first wall 21 facing away from the first recess 20 b .

[0311] When two battery cells 6 are arranged along the second direction Z, the first recess 20 b of one battery cell 6 can avoid the first electrode terminal 30 of the other battery cell 6 , thereby improving space utilization and enhancing the energy density of the battery.

[0312] For example, when two battery cells 6 are arranged along the second direction Z and need to be connected in parallel, the first recess 20b of one battery cell 6 can avoid the first electrode terminal 30 of the other battery cell 6, and the second recess 20e of the one battery cell 6 can avoid the second electrode terminal 50 of the other battery cell 6.

[0313] When two battery cells 6 are arranged along the second direction Z and need to be connected in series, the first recess 20 b of one battery cell 6 can avoid the second electrode terminal 50 of the other battery cell 6 , and the second recess 20 e of the one battery cell 6 can avoid the first electrode terminal 30 of the other battery cell 6 .

[0314] FIG10 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application; FIG11 is an enlarged schematic view of the box in FIG10 .

[0315] As shown in Figures 10 and 11, in some embodiments, the housing 20 includes a first wall 21 and a second wall 22, respectively located on either side of the accommodating cavity 20a along the second direction Z. The first recess 20b is recessed from the second wall 22 toward the first wall 21. The first electrode terminal 30 extends from the first wall 21 along the second direction Z. At least a portion of the first electrode portion 31 is located on a side of the first wall 21 facing away from the first recess 20b.

[0316] Exemplarily, the first wall 21 is a flat wall.

[0317] Illustratively, the first electrode terminal 30 passes through the first wall 21 .

[0318] When two battery cells 6 are arranged along the second direction Z, the first recess 20 b of one battery cell 6 can avoid the first electrode portion 31 of the other battery cell 6 , thereby improving space utilization and enhancing the energy density of the battery.

[0319] For example, when two battery cells 6 are arranged along the second direction Z and need to be connected in parallel, the first recess 20b of one battery cell 6 can avoid the first electrode portion 31 of the other battery cell 6, and the second recess 20e of the one battery cell 6 can avoid the second electrode terminal 50 of the other battery cell 6.

[0320] When two battery cells 6 are arranged along the second direction Z and need to be connected in series, the first recess 20 b of one battery cell 6 can avoid the second electrode terminal 50 of the other battery cell 6 , and the second recess 20 e of the one battery cell 6 can avoid the first electrode portion 31 of the other battery cell 6 .

[0321] In some embodiments, the first electrode terminal 30 further includes a second electrode portion 32 and a third electrode portion 33. The second electrode portion 32 passes through the first wall 21, and the first electrode portion 31 and the third electrode portion 33 extend in the same direction from both ends of the second electrode portion 32. The third electrode portion 33 is disposed within the accommodating cavity 20a and is stacked and connected to the first tab 11 in the second direction Z.

[0322] The second electrode portion 32 and the third electrode portion 33 are provided to facilitate connection between the first electrode terminal 30 and the first tab 11. The first electrode portion 31 and the third electrode portion 33 extend in the same direction, so that the first electrode portion 31 and the third electrode portion 33 can clamp a portion of the first wall 21 from both sides, thereby improving the connection strength between the first electrode terminal 30 and the first wall 21.

[0323] In some embodiments, the first electrode portion 31 and the third electrode portion 33 extend from both ends of the second electrode portion 32 in the first direction X. Exemplarily, the first electrode portion 31 and the third electrode portion 33 extend from both ends of the second electrode portion 32 toward the main body.

[0324] In some embodiments, a projection of the third electrode portion 33 along the second direction Z at least partially overlaps a projection of the first recess 20 b along the second direction Z. The third electrode portion 33 and the first recess 20 b may share space in the first direction X, thereby improving space utilization.

[0325] In some embodiments, a projection of an end of the first electrode portion 31 away from the second electrode portion 32 along the second direction Z is located within a projection of the first recess 20 b along the second direction Z.

[0326] In some embodiments, the first electrode portion 31 , the second electrode portion 32 , and the third electrode portion 33 form a C-shaped structure.

[0327] In some embodiments, the insulating member 40 insulates the first electrode terminal 30 from the first wall 21 .

[0328] In some embodiments, the first insulating layer 41 is bent into a C-shaped structure and separates the first electrode portion 31, the second electrode portion 32 and the third electrode portion 33 from the first wall 21, and the second insulating layer 42 is bent into a C-shaped structure and separates the first electrode portion 31 and the third electrode portion 33 from the first wall 21.

[0329] In some embodiments, a battery cell includes a housing, an electrode assembly, and a first electrode terminal. The housing has a accommodating cavity, and the Brinell hardness of the housing is greater than or equal to 30HB. The housing includes a first wall and a second wall, the first wall and the second wall are respectively located on either side of the accommodating cavity along a second direction. The housing is provided with a first recess, the first recess being recessed from the second wall toward the first wall. The electrode assembly is disposed in the accommodating cavity, and a first tab is provided at an end of the electrode assembly along the first direction, wherein the second direction is perpendicular to the first direction. The first electrode terminal includes a first electrode portion, a second electrode portion, and a third electrode portion. The first electrode portion is located outside the housing, the second electrode portion passes through the first wall, and the third electrode portion is disposed within the accommodating cavity, stacked and connected to the first tab in the second direction. The first electrode portion and the third electrode portion extend in the same direction from both ends of the second electrode portion, respectively. At least a portion of the first electrode portion is located on the side of the first wall facing away from the first recess, and the projection of the end of the first electrode portion away from the second electrode portion along the second direction is located within the projection of the first recess along the second direction.

[0330] FIG12 is a schematic structural diagram of a battery cell provided in some other embodiments of the present application; FIG13 is a schematic cross-sectional view taken along the AA direction of FIG12 .

[0331] As shown in FIG. 12 and FIG. 13 , in some embodiments, the first through hole 20 c and the second through hole 20 d are both provided in the first wall 21 .

[0332] The first through hole 20 c is provided on the first wall 21 , so that the electrolyte can be injected into the housing 20 along the second direction Z, thereby reducing the impact force of the electrolyte on the main body 13 .

[0333] In some embodiments, in the third direction Y, the first through hole 20 c is located at one side of the first electrode terminal 30 .

[0334] In some embodiments, in the third direction Y, the second through hole 20d is located at one side of the second electrode terminal 50. Alternatively, the first through hole 20c and the second through hole 20d are disposed diagonally.

[0335] In other embodiments, the first through hole 20c and the second through hole 20d are both provided in the second wall 22. In still other embodiments, the first through hole 20c is provided in the first wall 21, and the second through hole 20d is provided in the second wall 22. In still other embodiments, the first through hole 20c is provided in the second wall 22, and the second through hole 20d is provided in the first wall 21.

[0336] In some embodiments, the pressure relief mechanism 221 is disposed on the first wall 21. Optionally, the pressure relief mechanism 221 is disposed near an edge of the first wall 21.

[0337] In some embodiments, there are four pressure relief mechanisms 221 , and the four pressure relief mechanisms 221 are respectively disposed at the four corners of the first wall 21 .

[0338] FIG14 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0339] As shown in FIG14 , in some embodiments, the housing 25 includes a housing body 251 and a first edge portion 252 extending from the periphery of the housing body 251. The cover plate 26 includes a cover body 261 and a second edge portion 262 extending from the periphery of the cover body 261. The housing body 251 and the cover body 261 enclose an accommodating cavity 20 a. The first edge portion 252 and the second edge portion 262 are connected to form a sealing structure 27.

[0340] For example, the first edge portion 252 and the second edge portion 262 can be connected by bonding, welding or other means to form the sealing structure 27. For example, the shell body 251 and the cover body 261 are arranged along the second direction Z.

[0341] Illustratively, the housing body 251 includes a second wall 22 .

[0342] At least a portion of the first edge portion 252 is connected to the second edge portion 262 .

[0343] By providing the first edge portion 252 and the second edge portion 262 , the connection strength between the housing 25 and the cover plate 26 can be increased, thereby improving the sealing effect.

[0344] In some embodiments, at least a portion of the first edge portion 252 is welded to the second edge portion 262 to form a weld mark. The sealing structure 27 includes a weld mark. The welding process is simple and easy to implement. The weld mark has high strength and good sealing performance.

[0345] In some embodiments, the weld mark includes two long sides extending along the first direction and two short sides extending along the third direction Y. For example, the long sides can be formed by laser welding, and the short sides can be formed by ultrasonic welding.

[0346] In some embodiments, the width of the weld mark is 1 mm to 10 mm. Optionally, the width of the weld mark is 1 mm, 2 mm, 3 mm, 5 mm, 8 mm or 10 mm.

[0347] In some embodiments, non-penetrating laser welding is used to weld the first edge portion 252 and the second edge portion 262. For example, a laser is irradiated on the first edge portion 252, and the laser melts through the first edge portion 252 but does not melt through the second edge portion 262.

[0348] In some embodiments, after the shell 25 and the cover plate 26 are welded, cutting is performed on the weld mark to reduce the volume of the battery cell 6 .

[0349] In some embodiments, the first electrode tab 11 and the second electrode tab 12 pass through the first wall 21 .

[0350] In some embodiments, the weld mark surrounds the receiving cavity 20a.

[0351] In some embodiments, referring to Figures 6 and 14 , the first electrode terminal 30 passes between the first edge portion 252 and the second edge portion 262. The battery cell 6 further includes an insulating member 40. At least a portion of the insulating member 40 covers the portion of the first electrode terminal 30 located between the first edge portion 252 and the second edge portion 262 and is bonded to the first edge portion 252 and the second edge portion 262 to insulate the first electrode terminal 30 from the housing 25 and from the cap plate 26.

[0352] The insulating member 40 and the sealing structure 27 together achieve sealing of the housing 20 .

[0353] In some embodiments, at least a portion of the sealing structure 27 is bent toward the shell body 251. By bending the sealing structure 27, the maximum size of the battery cell 6 can be reduced and the energy density of the battery cell 6 can be increased.

[0354] In some embodiments, the sealing structure 27 is bonded to the shell body 251 through an adhesive layer.

[0355] In some embodiments, portions of the sealing structure 27 located on both sides of the shell body 251 along the third direction Y are bent toward the shell body 251 to reduce the size of the battery cell 6 along the third direction Y.

[0356] FIG15 is a schematic cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0357] As shown in FIG. 15 , in some embodiments, at least a portion of the sealing structure 27 is bent to a side of the cover body 261 facing away from the shell body 251 .

[0358] The embodiment of the present application can reduce the size of the battery cell 6 along the first direction X or the size of the battery cell 6 along the third direction Y.

[0359] In some embodiments, the sealing structure 27 is bonded to the cover body 261 through an adhesive layer.

[0360] FIG16 is a schematic diagram of the structure of a battery cell provided in some other embodiments of the present application; FIG17 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application.

[0361] As shown in Figures 16 and 17, in some embodiments, the first electrode tab 11 and the second electrode tab 12 are located at the same end of the electrode assembly 10 along the first direction X, so that the first electrode tab 11 and the second electrode tab 12 share space in the first direction X, thereby improving the space utilization of the battery cell 6 in the first direction X.

[0362] In some embodiments, the first electrode terminal 30 and the second electrode terminal 50 are disposed at the same end of the first wall 21 along the first direction X.

[0363] In some embodiments, the first electrode terminal 30 and the second electrode terminal 50 are arranged along the third direction Y.

[0364] According to some embodiments of the present application, the present application also provides a battery comprising a plurality of battery cells according to any of the above embodiments.

[0365] According to some embodiments of the present application, the present application further provides an electrical device comprising a battery cell according to any of the above embodiments, the battery cell being used to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems using the battery cell.

[0366] 3 to 6 , an embodiment of the present application provides a battery cell 6 , which includes a housing 20 , an electrode assembly 10 , a first electrode terminal 30 , a second electrode terminal 50 , and an insulating member 40 .

[0367] The electrode assembly 10 is housed in the housing 20 and includes a main body 13 , a first electrode tab 11 , and a second electrode tab 12 . The first electrode tab 11 and the second electrode tab 12 extend from both ends of the main body 13 along a first direction X, respectively.

[0368] The housing 20 includes a shell 25 and a cover plate 26. The shell 25 has an opening. The cover plate 26 covers the opening and defines a receiving chamber 20a with the shell 25. Both the shell 25 and the cover plate 26 are made of metal and are connected by welding. The hardness of the shell 25 is 30HB-60HB, and the hardness of the cover plate 26 is 30HB-60HB.

[0369] The first electrode terminal 30 passes between the housing 25 and the cover plate 26 and extends to the outside of the outer shell 20. A portion of the first electrode terminal 30 is disposed within the accommodating cavity 20 a and is stacked and connected to the first electrode tab 11 in the second direction Z. The second electrode terminal 50 passes between the housing 25 and the cover plate 26 and extends to the outside of the outer shell 20. A portion of the second electrode terminal 50 is disposed within the accommodating cavity 20 a and is stacked and connected to the second electrode tab 12 in the second direction Z. The second direction Z is perpendicular to the first direction X.

[0370] The insulating member 40 surrounds the outer periphery of the first electrode terminal 30 and insulates the first electrode terminal 30 from the housing 25 and the first electrode terminal 30 from the cover plate 26.

[0371] The housing 25 is provided with a pressure relief mechanism 221. The housing 25 is provided with a first through hole 20c and a second through hole 20d, which are respectively connected to both ends of the accommodating cavity 20a along the first direction X, and the first through hole 20c is used for injecting electrolyte.

[0372] FIG18 is a schematic flow chart of a method for manufacturing a battery cell according to some embodiments of the present application.

[0373] 3 to 18 , the present application also provides a method for manufacturing a battery cell, which includes:

[0374] S100, providing an electrode assembly 10, wherein a first electrode tab 11 is provided at an end portion of the electrode assembly 10 along a first direction X;

[0375] S200, providing a first electrode terminal 30;

[0376] S300, connecting the first electrode tab 11 and the first electrode terminal 30;

[0377] S400 , providing a housing 20 , and placing the electrode assembly 10 in the accommodating cavity 20 a of the housing 20 .

[0378] The Brinell hardness of the outer shell 20 is greater than or equal to 30 HB. A portion of the first electrode terminal 30 is disposed in the accommodation cavity 20 a , and the first electrode terminal 30 passes through the outer shell 20 and extends to the outside of the outer shell 20 .

[0379] The first electrode terminal 30 is connected to the first tab 11, allowing them to share a portion of the space in the first direction X. This increases space utilization in the first direction X and improves the energy density of the battery cell 6. Furthermore, the direct connection between the first electrode terminal 30 and the first tab 11 eliminates the need for a transition structure, thereby simplifying the structure of the battery cell 6 and improving its energy density. The housing 20 has a high degree of rigidity and is not easily crushed when squeezed, thereby protecting the electrode assembly 10 and improving the reliability of the battery cell 6.

[0380] In some embodiments, step S300 includes: welding the first electrode tab 11 to the first electrode terminal 30. Exemplarily, the first electrode tab 11 is connected to the first electrode terminal 30 by ultrasonic welding.

[0381] The first electrode tab 11 is welded to the first electrode terminal 30 to reduce the contact resistance between the first electrode tab 11 and the first electrode terminal 30 , improve the overcurrent capacity, and increase the connection strength between the first electrode tab 11 and the first electrode terminal 30 .

[0382] In some embodiments, step S400 includes:

[0383] S410 , providing a housing 25 , wherein the housing 25 includes a housing body 251 and a first edge portion 252 extending from a periphery of the housing body 251 ;

[0384] S420, placing the electrode assembly 10 into the shell body 251;

[0385] S430 , providing a cover plate 26 , the cover plate 26 including a cover body 261 and a second edge portion 262 extending from a periphery of the cover body 261 ;

[0386] S440 , cover the cover plate 26 onto the housing 25 , connect the first edge portion 252 and the second edge portion 262 , and form a sealing structure 27 .

[0387] The case body 251 and the cover body 261 define a receiving cavity 20 a , and the first electrode terminal 30 passes between the first edge portion 252 and the second edge portion 262 .

[0388] In some embodiments, step S440 includes: connecting the first edge portion 252 and the second edge portion 262 by laser welding to form the sealing structure 27 .

[0389] The welding process is simple and easy to implement.

[0390] Exemplarily, the first edge portion 252 and the second edge portion 262 are connected by laser welding and / or ultrasonic welding.

[0391] In some embodiments, the manufacturing method further includes: step S500, cutting the sealing structure 27. By cutting the sealing structure 27, the volume of the battery cell can be reduced.

[0392] In some embodiments, the manufacturing method further includes: step S600, bending the sealing structure 27 toward the shell body 251. By bending the sealing structure 27, the maximum size of the battery cell 6 can be reduced and the energy density of the battery cell 6 can be increased.

[0393] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A battery cell, comprising: A shell having a receiving cavity, wherein the Brinell hardness of the shell is greater than or equal to 30 HB; An electrode assembly is disposed in the accommodating cavity, and a first electrode tab is disposed at an end of the electrode assembly along a first direction; as well as A first electrode terminal, a portion of which is disposed in the accommodation cavity and connected to the first electrode tab, and the first electrode terminal passes through the shell and extends to the outside of the shell.

2. The battery cell according to claim 1, wherein: The first electrode tab is welded to the first electrode terminal. 3 . The battery cell according to claim 1 , further comprising an insulating member, at least a portion of which is disposed between the outer case and the first electrode terminal and is used to insulate the outer case from the first electrode terminal.

4. The battery cell according to claim 3, wherein: The insulating member is bonded to the housing and the first electrode terminal.

5. The battery cell according to claim 4, wherein: At an ambient temperature of 25° C., an elastic modulus of the insulating member is smaller than an elastic modulus of the first electrode terminal.

6. The battery cell according to any one of claims 3 to 5, wherein: The insulating member includes a first insulating layer and a second insulating layer which are stacked and extend along the first direction, and the first electrode terminal passes through between the first insulating layer and the second insulating layer; In the first direction, the inner end of the first electrode terminal exceeds the inner end of the second insulating layer, and the portion of the first electrode terminal exceeding the second insulating layer is connected to the first electrode tab; In the first direction, an inner end of the first insulating layer exceeds an inner end of the first electrode terminal.

7. The battery cell according to any one of claims 1 to 6, wherein: The housing is provided with a first recessed portion, and the first recessed portion is arranged outside the accommodating cavity; The first electrode terminal includes a first electrode portion located outside the housing, wherein a projection of the first electrode portion along a second direction at least partially overlaps a projection of the first recess along the second direction, and the second direction is perpendicular to the first direction.

8. The battery cell according to claim 7, wherein: The first electrode portion extends from an end portion of the housing along the first direction; At least a portion of the first electrode portion is accommodated in the first recess, or at least a portion of the first electrode portion is located on a side of the housing away from the first recess along the second direction.

9. The battery cell according to claim 7, wherein: The housing comprises a first wall and a second wall, wherein the first wall and the second wall are respectively located on both sides of the accommodation cavity along the second direction; the first recess is recessed from the second wall toward the first wall; and the first electrode terminal extends from the first wall along the second direction; At least a portion of the first electrode portion is located on a side of the first wall away from the first recess.

10. The battery cell according to claim 9, wherein: The first electrode terminal further includes a second electrode portion and a third electrode portion, the second electrode portion passes through the first wall, and the first electrode portion and the third electrode portion extend from both ends of the second electrode portion toward the same direction respectively; The third electrode portion is disposed in the accommodation cavity, and is stacked and connected to the first electrode tab in the second direction.

11. The battery cell according to any one of claims 1 to 10, wherein: The dimension of the housing along the first direction is greater than the dimension of the housing along the second direction; A dimension of the housing along the first direction is greater than a dimension of the housing along a third direction, and the third direction, the first direction, and the second direction are perpendicular to each other.

12. The battery cell according to claim 11, wherein: The size of the shell along the first direction is L1, the size of the shell along the second direction is L2, and the size of the shell along the third direction is L3; 1.2≤L1 / L3≤18, 1.2≤L3 / L2≤15.

13. The battery cell according to any one of claims 1 to 12, wherein: The housing comprises a first wall and a second wall arranged opposite to each other along a second direction, the second direction is perpendicular to the first direction and parallel to the thickness direction of the battery cell, and the first wall and the second wall are both flat walls; The second wall is provided with a pressure relief mechanism.

14. The battery cell according to claim 13, wherein: The second wall has two edges arranged opposite to each other along the first direction, and the distances between the pressure relief mechanism and the two edges in the first direction are D1 and D2 respectively; D1 / D2 is 0.5-2.

15. The battery cell according to any one of claims 1 to 14, wherein: The housing is provided with a first through hole and a second through hole, the first through hole and the second through hole are respectively connected with two ends of the accommodating cavity along the first direction, and the first through hole and / or the second through hole are used for injecting electrolyte.

16. The battery cell according to claim 15, wherein: The housing comprises a first wall and a second wall, wherein the first wall and the second wall are respectively located at two sides of the accommodating cavity along a second direction, and the second direction is perpendicular to the first direction; The first through hole and the second through hole are both arranged in the first wall; or, the first through hole and the second through hole are both arranged in the second wall; or, the first through hole is arranged in the first wall, and the second through hole is arranged in the second wall.

17. The battery cell according to claim 15, wherein: The housing comprises a third wall and a fourth wall, wherein the third wall and the fourth wall are respectively located at two ends of the accommodating cavity along the first direction; The third wall is provided with the first through hole, and the fourth wall is provided with the second through hole.

18. The battery cell according to claim 17, wherein: The electrode assembly includes a main body, the first electrode tab extends from the main body along the first direction and beyond the third wall. In the first direction, the first through hole at least partially overlaps with the first electrode tab.

19. The battery cell according to any one of claims 15 to 18, wherein: The aperture of the first through hole is H1, the volume of the accommodating cavity is H2, and 100 ml / mm≤H2 / H1≤1000 ml / mm.

20. The battery cell according to any one of claims 1 to 19, wherein: The housing comprises: The housing comprises a housing body and a first edge portion extending from a periphery of the housing body; The cover plate comprises a cover body and a second edge portion extending from the periphery of the cover body, the shell body and the cover body enclose the accommodating cavity, and the first edge portion and the second edge portion are connected to form a sealing structure.

21. The battery cell according to claim 20, wherein: At least a portion of the first edge portion is welded to the second edge portion to form a weld mark, and the sealing structure includes the weld mark.

22. The battery cell according to claim 20 or 21, wherein: The first electrode terminal passes between the first edge portion and the second edge portion; The battery cell also includes an insulating member, which at least partially covers a portion of the first electrode terminal located between the first edge portion and the second edge portion and is bonded to the first edge portion and the second edge portion to insulate the first electrode terminal from the shell and from the cover plate.

23. The battery cell according to any one of claims 20 to 22, wherein: At least a portion of the sealing structure is bent toward the shell body; or At least a portion of the sealing structure is bent to a side of the cover body facing away from the shell body.

24. The battery cell according to any one of claims 20 to 23, wherein: The cover plate and the shell are both made of aluminum.

25. The battery cell according to any one of claims 20 to 24, wherein: The hardness of the cover plate is in the range of 30HB-60HB, and the thickness of the cover plate is in the range of 0.02mm-2mm; and / or The hardness of the shell is in the range of 30HB-60HB, and the thickness of the shell is in the range of 0.02mm-5mm.

26. The battery cell according to any one of claims 1 to 25, wherein: The electrode assembly also includes a second electrode tab; The battery cell further includes a second electrode terminal, a portion of which is disposed in the accommodation cavity and connected to the second electrode tab, and the second electrode terminal passes through the outer shell and extends to the outside of the outer shell.

27. The battery cell according to claim 26, wherein: The first electrode tab and the second electrode tab are respectively located at two ends of the electrode assembly along the first direction; or, The first electrode tab and the second electrode tab are located at the same end of the electrode assembly along the first direction.

28. A battery comprising a plurality of battery cells according to any one of claims 1 to 27.

29. An electrical device comprising the battery according to claim 28, wherein the battery is used to provide electrical energy.

30. A method for manufacturing a battery cell, comprising: Providing an electrode assembly, wherein an end portion of the electrode assembly along a first direction is provided with a first electrode tab; providing a first electrode terminal; connecting the first electrode tab and the first electrode terminal; Providing a housing, and placing the electrode assembly in a receiving cavity of the housing; The Brinell hardness of the shell is greater than or equal to 30HB, a portion of the first electrode terminal is disposed in the accommodating cavity, and the first electrode terminal passes through the shell and extends to the outside of the shell.

31. The manufacturing method according to claim 30, wherein: The step of connecting the first electrode tab and the first electrode terminal comprises: The first electrode tab is welded to the first electrode terminal.

32. The manufacturing method according to claim 30, wherein: The step of providing a housing and placing the electrode assembly in the housing cavity of the housing comprises: Providing a shell, the shell comprising a shell body and a first edge portion extending from a periphery of the shell body; placing the electrode assembly into the shell body; Providing a cover plate, the cover plate comprising a cover body and a second edge portion extending from a periphery of the cover body; Covering the cover plate onto the housing to connect the first edge portion and the second edge portion and form a sealing structure; The shell body and the cover body enclose the accommodating cavity, and the first electrode terminal passes through between the first edge portion and the second edge portion.

33. The manufacturing method according to claim 32, wherein: The step of connecting the first edge portion and the second edge portion to form a sealing structure comprises: The first edge portion and the second edge portion are connected by laser welding to form the sealing structure.

34. The manufacturing method according to claim 33, further comprising: cutting the sealing structure; The sealing structure is bent toward the shell body.

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