Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and an electric equipment. The battery monomer comprises a shell, an electrode assembly and a terminal part. The shell comprises a wall part. The electrode assembly is accommodated in the shell, and the electrode assembly comprises an electrode main body and a tab led out from the electrode main body. The terminal part is located on the side of the wall part away from the electrode main body, and the terminal part is provided with a base area and a thinning area. The maximum thickness of the thinning area is less than the maximum thickness of the base area. In the direction of the electrode main body pointing to the wall part, a part of the base area protrudes from the surface of the thinning area away from the wall part.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery device, and an electrical appliance. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, improving energy density is one of the research directions. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance that can improve energy density.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and a terminal portion. The housing includes a wall portion. The electrode assembly is housed within the housing and includes an electrode body and tabs extending from the electrode body. The terminal portion is located on the side of the wall portion facing away from the electrode body, and the terminal portion has a substrate region and a thinned region, the maximum thickness of the thinned region being less than the maximum thickness of the substrate region. Along the direction from the electrode body to the wall portion, a portion of the substrate region protrudes from the surface of the thinned region facing away from the wall portion.

[0006] This embodiment of the application, by setting a thinning zone, provides installation space for the busbar component on the side of the thinning zone facing away from the wall, thereby improving space utilization. Setting a thinning zone also reduces the volume and weight of the battery cell, increasing its energy density.

[0007] In some embodiments, the terminal portion includes a first conductive portion and a second conductive portion, both of which are electrically connected to a tab. The melting point of the second conductive portion is higher than that of the first conductive portion. At least a portion of the first conductive portion and at least a portion of the second conductive portion are formed in a thinning region; in the thinning region, at least a portion of the second conductive portion is located between the first conductive portion and the wall portion.

[0008] When welding the busbar components and thinning areas, the second conductive part with a higher melting point is less likely to be melted through, thereby reducing the risk of damage to other components of the battery cell and improving the reliability of the battery cell.

[0009] In some embodiments, the first conductive portion includes a first base and a first extension connected to the first base. Along the direction from the electrode body towards the wall portion, a portion of the first base protrudes from the surface of the first extension facing away from the wall portion. The first base is formed in the substrate region, and the first extension is formed in the thinned region; the first base is electrically connected to the tab and the first extension. In the thickness direction of the wall portion, at least a portion of the second conductive portion is located between the first extension and the wall portion.

[0010] The first base portion can electrically connect the electrode tab to the first extension portion, thereby reducing the current flowing through the contact surface between the second conductive portion and the first conductive portion during the charging and discharging of the battery cell, reducing resistance, and shortening the conductive path.

[0011] In some embodiments, the first base has a first end face facing away from the wall. A first recess is provided on one side of the first conductive portion facing away from the wall along the thickness direction. The first recess is recessed relative to the first end face, and a first extension corresponds to the bottom surface of the first recess. The first recess can be used to accommodate a portion of the busbar component, reducing the space occupied by the terminal portion and the busbar component in the thickness direction of the wall and improving space utilization.

[0012] In some embodiments, the first base has a second end face facing the wall. A second recess is provided on the side of the first conductive portion facing the wall along the thickness direction. The second recess is recessed relative to the second end face, and at least a portion of the first extension is formed between the second recess and the first recess. At least a portion of the second conductive portion is accommodated in the second recess. In embodiments of this application, by providing the second recess, the size of the second conductive portion protruding from the second end face can be reduced, thereby reducing the space occupied by the terminal portion in the thickness direction and improving space utilization.

[0013] In some embodiments, the second conductive portion is entirely housed within the second recess. The two conductive portions and the first base portion can share space in the thickness direction of the wall portion, thereby reducing the maximum dimension of the terminal portion in the thickness direction and improving space utilization.

[0014] In some embodiments, the surface of the second conductive portion facing the wall is flush with the second end face. Embodiments of this application can improve the flatness of the side of the terminal portion facing the wall and simplify the structure of the components of the battery cell that contact the terminal portion.

[0015] In some embodiments, a portion of the second conductive portion protrudes from the second end face along the direction from the terminal portion to the wall portion. Given a fixed thickness of the second conductive portion, setting a portion of the second conductive portion to protrude from the second end face reduces the required depth of the second recess; correspondingly, when the depth of the second recess decreases, the depth of the first recess can increase, thereby providing more installation space for the busbar component.

[0016] In some embodiments, a third recess is provided on the side of the wall portion facing the terminal portion, and the orthographic projection of the terminal portion lies within the orthographic projection of the third recess in the same plane perpendicular to the thickness direction. The third recess includes a first sub-recess and a second sub-recess that are interconnected, and the depth of the second sub-recess is greater than the depth of the first sub-recess in the thickness direction. The orthographic projection of the second conductive portion lies within the orthographic projection of the second sub-recess in the same plane perpendicular to the thickness direction. By providing a second sub-recess with a greater depth, the distance between the wall portion and the second conductive portion can be increased, providing mounting space for other components.

[0017] In some embodiments, a portion of the second conductive portion is accommodated in the second sub-recess. Embodiments of this application can improve space utilization.

[0018] In some embodiments, the orthographic projection of the first extension lies within the orthographic projection of the second conductive portion in the same plane perpendicular to the thickness direction. The second conductive portion can completely separate the first extension from the wall portion, thereby reducing the risk of the thinned area being welded through when welding the busbar and the first extension.

[0019] In some embodiments, the electrode assembly includes multiple tabs, including a positive tab and a negative tab. The battery cell includes multiple terminal portions, including a positive terminal portion and a negative terminal portion, with the positive terminal portion electrically connected to the positive tab and the negative terminal portion electrically connected to the negative tab. A first base portion of the negative terminal portion has a fourth recess on its side facing away from the wall portion. The negative terminal portion also includes a third conductive portion, at least partially accommodated in the fourth recess portion and connected to the first base portion; the third conductive portion forms part of the base region. The third conductive portion is electrically connected to the negative tab, and the material of the third conductive portion is the same as the material of the negative tab.

[0020] By using a third conductive part and a negative electrode tab made of the same material, the connection process between the third conductive part and the negative electrode tab can be simplified, and the resistance between the negative terminal and the negative electrode tab can be reduced. The fourth recess can accommodate at least a portion of the third conductive part, thereby reducing the maximum dimension of the substrate region in the thickness direction.

[0021] In some embodiments, the material of the third conductive portion is the same as the material of the second conductive portion. This application embodiment can reduce the number of material types, which is beneficial for reducing costs and simplifying the manufacturing process of the negative terminal.

[0022] In some embodiments, the second conductive portion includes a second base and a second extension connected to the second base. At least a portion of the second base is formed in the substrate region, and the second extension is formed in the thinned region. The second base is electrically connected to the tab and the second extension. In the thickness direction of the wall portion, the second extension is located between the first conductive portion and the wall portion. Along the direction from the electrode body to the wall portion, a portion of the second base protrudes from the surface of the first conductive portion facing away from the wall portion. In this embodiment, forming at least a portion of the second base in the substrate region can improve the high-temperature resistance of the substrate region.

[0023] In some embodiments, the second base has a third end face facing away from the wall. The second conductive portion has a fifth recess recessed from the third end face towards the wall, and the second extension corresponds to the bottom face of the fifth recess. The first conductive portion is accommodated in the fifth recess; in the thickness direction, the depth of the fifth recess is greater than the thickness of the first conductive portion. The fifth recess can be used to accommodate a portion of the busbar component, reducing the space occupied by the terminal portion and the busbar component in the thickness direction of the wall and improving space utilization.

[0024] In some embodiments, a sixth recess is provided on the side of the second base facing the wall. At least a portion of the second extension protrudes from the bottom surface of the sixth recess along the direction from the terminal portion to the wall. A third recess is provided on the side of the wall facing the terminal portion, and the orthographic projection of the terminal portion lies within the third recess in the same plane perpendicular to the thickness direction. The third recess includes a first sub-recess and a second sub-recess that are interconnected, and the depth of the second sub-recess is greater than the depth of the first sub-recess in the thickness direction. In the same plane perpendicular to the thickness direction, the orthographic projection of the second extension lies within the orthographic projection of the second sub-recess, and the orthographic projection of the bottom surface of the sixth recess lies within the orthographic projection of the first sub-recess.

[0025] By providing a deeper second recess, the distance between the wall and the second extension can be increased, providing installation space for other components.

[0026] In some embodiments, the electrode assembly includes multiple tabs, including a positive tab and a negative tab. The battery cell includes multiple terminal portions, including a positive terminal portion and a negative terminal portion. The positive terminal portion is electrically connected to the positive tab, and the negative terminal portion is electrically connected to the negative tab. The second conductive portion of the negative terminal portion is made of the same material as the negative tab. By using the same material for the second conductive portion and the negative tab, the connection process between the second conductive portion and the negative tab can be simplified, and the resistance between the negative terminal portion and the negative tab can be reduced.

[0027] In some embodiments, the first conductive part is made of aluminum or an aluminum alloy, and the second conductive part is made of copper or a copper alloy. The first conductive part is made of aluminum or an aluminum alloy. Aluminum and aluminum alloys have good thermal conductivity, allowing the aluminum first conductive part to dissipate heat quickly during welding, reducing localized overheating. Compared to aluminum, copper has a higher melting point; using a copper second conductive part can reduce the risk of the thinned area melting through, improving the reliability of the battery cell.

[0028] In some embodiments, the melting point of the second conductive part is greater than or equal to 800°C, which can reduce the risk of the second conductive part being burned through.

[0029] In some embodiments, the substrate region and the thinning region are arranged along the length of the wall. The thinning region can have a larger dimension along the length of the wall, thereby increasing the welding area between the thinning region and the busbar component and improving the flow capacity.

[0030] In some embodiments, in the thinning region, the minimum thickness of the first conductive part is T3, the minimum thickness of the second conductive part is T4, and 0.2 ≤ T4 / T3 ≤ 0.8. In this embodiment, setting T4 / T3 to be greater than or equal to 0.2 can reduce the risk of the second conductive part being melted through; setting T4 / T3 to be less than or equal to 0.8 allows the first conductive part to have a higher thickness, improving the welding strength and current carrying capacity between the first conductive part and the busbar component.

[0031] In some embodiments, the maximum thickness of the substrate region is T1, the maximum thickness of the thinned region is T2, and 0.4 ≤ T2 / T1 ≤ 0.9. In this embodiment, setting T2 / T1 to be greater than or equal to 0.4 can reduce the risk of the thinned region being melted through during welding; setting T2 / T1 to be less than or equal to 0.9 in this embodiment can provide more space for the busbar component and improve space utilization.

[0032] In some embodiments, the thickness of the thinning region is 1mm-2.5mm. In this application embodiment, the thickness of the thinning region is set to be greater than or equal to 1mm to reduce the risk of the thinning region being soldered through. In this application embodiment, the thickness of the thinning region is set to be less than or equal to 2.5mm to reduce the space and weight occupied by the thinning region and improve the energy density of the battery cell.

[0033] In some embodiments, the wall portion is provided with electrode lead-out holes. The battery cell also includes a terminal post, which comprises a first portion and a second portion connected to each other. The first portion is located on the side of the wall portion facing the electrode assembly and is electrically connected to a tab. In the thickness direction of the wall portion, a portion of the wall portion is located between the substrate region and the first portion. At least a portion of the second portion is accommodated in the electrode lead-out holes, and the second portion is connected to the substrate region. The substrate region and the first portion can clamp the wall portion from both sides, thereby fixing the terminal portion and the terminal post to the wall portion. Compared to the thinned region, the substrate region has a larger thickness; connecting the second portion to the substrate region can increase the connection strength and improve the stability of the terminal portion.

[0034] In some embodiments, a third recess is provided on the side of the wall portion facing the terminal portion. In the same plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the terminal portion lies within the orthographic projection of the third recess. The third recess includes a first sub-recess and a second sub-recess that communicate with each other. In the thickness direction, the depth of the second sub-recess is greater than the depth of the first sub-recess. In the same plane perpendicular to the thickness direction, the orthographic projection of the thinning region at least partially overlaps with the orthographic projection of the second sub-recess. By providing a second sub-recess with a greater depth, the distance between the wall portion and the thinning region can be increased, providing mounting space for other components.

[0035] Secondly, embodiments of this application provide a battery device, which includes a battery cell and a busbar component provided in any of the embodiments of the first aspect. A portion of the busbar component is located on the side of the thinning region facing away from the wall and is connected to the thinning region.

[0036] By setting a thinning zone, the total space occupied by the busbar and terminal parts in the thickness direction of the wall can be reduced, thereby improving space utilization.

[0037] In some embodiments, the busbar component is welded to the first conductive portion located in the thinning region to form a weld portion, and the orthographic projection of the weld portion is located within the orthographic projection of the second conductive portion in the same plane perpendicular to the thickness direction of the wall portion.

[0038] When welding the busbar components and thinning areas, the second conductive part with a higher melting point is less likely to be melted through, thereby reducing the risk of damage to other components of the battery cell and improving the reliability of the battery cell.

[0039] In some embodiments, the welded portion and the second conductive portion are spaced apart in the thickness direction. Embodiments of this application can reduce the risk of localized melting of the second conductive portion and minimize the impact on the connection interface between the first and second conductive portions.

[0040] Thirdly, embodiments of this application provide an electrical device including a battery device provided in any of the embodiments of the second aspect, the battery device being used to provide electrical energy. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0042] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0043] Figure 2 Schematic diagram of a battery device provided for some embodiments of this application;

[0044] Figure 3 This is an exploded schematic diagram of a battery cell in some embodiments of this application;

[0045] Figure 4 Simplified schematic diagram of a battery device provided in some embodiments of this application;

[0046] Figure 5 for Figure 4 A cross-sectional view along the AA direction;

[0047] Figure 6 for Figure 5 An enlarged view of box A;

[0048] Figure 7 This is an exploded view of a portion of the structure of a battery cell provided in some embodiments of this application;

[0049] Figure 8 A schematic diagram of the structure of the positive terminal of a battery cell provided in some embodiments of this application;

[0050] Figure 9 for Figure 8 The diagram shows an explosion of the positive terminal part;

[0051] Figure 10 for Figure 5 Enlarged view at box C;

[0052] Figure 11 A schematic diagram of the negative terminal portion of a battery cell provided in some embodiments of this application;

[0053] Figure 12 A partially enlarged schematic diagram of a battery cell provided for other embodiments of this application;

[0054] Figure 13 for Figure 12 Enlarged view of the area within the circle;

[0055] Figure 14 Exploded view of a portion of the structure of a battery cell provided in other embodiments of this application;

[0056] Figure 15 for Figure 14 A schematic diagram of the positive terminal sub-section is shown;

[0057] Figure 16 A partial cross-sectional schematic diagram of a battery cell provided for some embodiments of this application;

[0058] Figure 17 An exploded view of a portion of the structure of a battery cell provided in some embodiments of this application;

[0059] Figure 18 for Figure 17 The diagram shows the negative terminal part.

[0060] The annotations in the attached figures are explained as follows:

[0061] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing; 5b. Second housing; 6. Battery cell; 7. Busbar assembly;

[0062] 10. Electrode assembly; 11. Electrode body; 12. Tab; 12a. Positive tab; 12b. Negative tab;

[0063] 20. Outer shell; 20a. Housing; 20b. End cap; 21. Wall portion; 211. Electrode lead-out hole; 212. Third recess; 2121. First sub-recess; 2122. Second sub-recess;

[0064] 30. Electrode terminals;

[0065] 40. Pressure relief mechanism;

[0066] 50. Terminal portion; 501. Positive terminal portion; 502. Negative terminal portion; 50a. Substrate region; 50b. Thinned region; 50c. Through hole; 51. First conductive portion; 511. First base portion; 511a. First end face; 511b. Second end face; 512. First extension portion; 5121. First sub-portion; 5122. Second sub-portion; 513. First recess; 513a. Bottom surface of the first recess; 514. Second recess; 514a. Bottom surface of the second recess; 515. Fourth recess; 52. Second conductive portion; 521. Second base portion; 521a. Third end face; 522. Second extension portion; 523. Fifth recess; 523a. Bottom surface of the fifth recess; 523b. Stepped surface; 524. Sixth recess; 524a. Bottom surface of the sixth recess; 53. Third conductive portion;

[0067] 60. Pole post; 61. Part 1; 62. Part 2;

[0068] 70. First insulating component; 80. Second insulating component; 90. Sealing component;

[0069] W, welded section; X, length direction; Y, width direction; Z, thickness direction. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0071] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0072] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0073] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0074] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0075] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0076] In this application, "multiple" means two or more (including two).

[0077] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0078] A single battery cell can be a rechargeable battery, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0079] A battery device typically refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. Within a battery device, multiple battery cells can be connected in series, parallel, or a combination of these connections via busbars.

[0080] Typically, the busbar component and the terminal portion of the battery cell are stacked and welded together. In the stacking direction of the busbar component and the terminal portion, the terminal portion and the busbar component will occupy more space, which will affect the energy density of the battery device.

[0081] In view of this, the present application provides a technical solution that can provide installation space for the bus component by partially thinning the terminal portion, thereby improving space utilization and increasing energy density.

[0082] The battery cells described in this application are applicable to battery devices and electrical equipment using battery devices. Electrical equipment can be devices that use battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0083] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0084] Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0085] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0086] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0087] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0088] Figure 2 A schematic diagram of a battery device provided for some embodiments of this application.

[0089] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0090] A battery cell assembly may include multiple battery cells 6, which are connected in series, parallel, or mixed connection via a busbar. Mixed connection means that multiple battery cells 6 are connected in both series and parallel.

[0091] Battery cell 6 can be a secondary battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0092] As an example, the battery cell 6 can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0093] As an example, the battery cell 6 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0094] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells 6; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 6 into a single module. As an example, a battery module can be formed by bundling multiple battery cells 6 together with cable ties.

[0095] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 5 and one or more battery cell assemblies housed within the housing 5. As an example, the battery cell assembly may be a battery module, which can be housed within the housing by securing the battery module to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells 6 to the housing.

[0096] In some embodiments, the housing 5 is used to house the battery cell 6, and the housing 5 can have various structures.

[0097] In some embodiments, the housing 5 may include a first housing 5a and a second housing 5b. The first housing 5a and the second housing 5b are fastened together to form a closed space inside the housing 5 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0098] In some embodiments, the housing 5 may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the housing to accommodate individual battery cells. As an example, the frame may include multiple side beams.

[0099] In some embodiments, the housing 5 may be part of the vehicle's chassis structure. For example, a portion of the housing 5 may be at least a portion of the vehicle's floor, or a portion of the housing 5 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0100] In some embodiments, the battery device 2 may be an energy storage device.

[0101] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0102] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0103] Figure 3 This is an exploded schematic diagram of a battery cell in some embodiments of this application.

[0104] Reference Figure 3 The battery cell 6 includes a housing 20 and an electrode assembly 10, with at least a portion of the electrode assembly 10 housed within the housing 20.

[0105] In some embodiments, the outer casing 20 can be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc.

[0106] In some embodiments, the housing 20 can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, it serves to protect the electrode assembly, and a sealing bag is included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the housing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0107] In some embodiments, the casing 20 of the battery cell 6 is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0108] In some embodiments, the housing 20 includes a housing 20a and an end cap 20b, the housing 20a having an opening, and the end cap 20b being connected to the housing 20a and covering the opening.

[0109] The housing 20a is a component used to fit the end cap 20b to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, the electrolyte, and other components.

[0110] The housing 20a and the end cap 20b can be separate components. For example, an opening can be provided on the housing 20a, and the end cap 20b can be used to close the opening to form an internal cavity for the battery cell 6.

[0111] The housing 20a can have various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing 20a can be determined according to the specific shape and size of the electrode assembly 10. The housing 20a can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0112] The shape of the end cap 20b can be adapted to the shape of the housing 20a to fit the housing 20a. The material of the end cap 20b can be the same as or different from the material of the housing 20a. Optionally, the end cap 20b can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap 20b is not easily deformed when subjected to compression and impact, so that the battery cell 6 can have higher structural strength and improve reliability.

[0113] The end cap 20b is connected to the housing 20a by welding, bonding, snap-fitting or other means.

[0114] The housing 20a may be open at one end or open at both ends. In some examples, the housing 20a may be a structure with an opening on one side, and one end cap 20b is provided to cover the housing 20a. In other examples, the housing 20a may also be a structure with openings on both sides, and two end caps 20b are provided, with the two end caps 20b respectively covering the two openings of the housing 20a.

[0115] In some embodiments, the electrode assembly 10 is a component in the battery cell 6 where an electrochemical reaction occurs. The housing 20 may contain one or more electrode assemblies 10. Optionally, the electrode assembly 10 is housed within the housing 20.

[0116] In some embodiments, the electrode assembly 10 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 6, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive and negative electrodes.

[0117] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a layer of positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0118] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0119] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0120] As an example, the positive electrode active material layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides 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, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0121] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0122] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0123] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0124] As an example, the negative electrode sheet may include a negative electrode current collector and a layer of negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0125] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0126] As an example, the negative electrode active material layer includes a negative electrode active material, which may be a negative electrode active material known in the art for use in battery cells. 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, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0127] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0128] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0129] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0130] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0131] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0132] As an example, the main 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. When the separator is a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0133] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0134] In some embodiments, the battery cell 6 further includes an electrolyte housed within the casing 20. The electrolyte acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid.

[0135] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0136] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0137] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0138] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0139] In some embodiments, the gel electrolyte comprises a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0140] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0141] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0142] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0143] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0144] The electrode assembly 10 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0145] In some embodiments, the electrode assembly 10 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0146] In some embodiments, the electrode assembly 10 has a stacked structure.

[0147] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0148] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0149] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0150] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0151] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0152] In some embodiments, the electrode assembly 10 may be cylindrical, flat, or polygonal in shape.

[0153] In some embodiments, the electrode assembly 10 includes tabs 12 that can conduct current from the electrode assembly 10. Exemplarily, the electrode assembly 10 includes a plurality of tabs 12, including a positive tab 12a and a negative tab 12b.

[0154] In some embodiments, the positive current collector includes a positive tab 12a, at least a portion of which is not covered by the positive active material layer. The negative current collector includes a negative tab 12b, at least a portion of which is not covered by the negative active material layer.

[0155] In some embodiments, the battery cell 6 further includes an electrode terminal 30, which is disposed on the housing 20 and electrically connected to the tab 12.

[0156] The electrode terminal 30 can be disposed on the end cover 20b or on the housing 20a.

[0157] The electrode terminal 30 can be directly connected to the tab 12, or it can be indirectly connected to the tab 12 through the current collector.

[0158] In some embodiments, there may be multiple electrode terminals 30, a portion of which are positive terminals and another portion of which are negative terminals. The positive terminal is electrically connected to the positive tab 12a, and the negative terminal is electrically connected to the negative tab 12b.

[0159] In some embodiments, a pressure relief mechanism 40 is provided on the housing 20. The pressure relief mechanism 40 is used to release the internal gas of the battery cell 6.

[0160] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0161] As an example, the pressure relief mechanism 40 can be integrally formed with the housing 20.

[0162] As an example, the pressure relief mechanism 40 can also be separately configured and connected to the housing 20.

[0163] The term "actuation" as used in this application refers to the pressure relief mechanism 40 being activated or undergoing a certain state, thereby releasing the internal pressure and temperature of the battery cell. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the pressure relief mechanism to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief mechanism, etc. When the pressure relief mechanism is actuated, the high-temperature, high-pressure substances inside the battery cell are discharged outwards from the actuated portion as waste. This method enables pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0164] In some embodiments, when the housing 20 is a non-sealed structure, the pressure relief mechanism 40 can be configured as a through hole for discharging gas inside the battery cell 6.

[0165] The emissions from battery cell 6 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0166] Figure 4 Simplified schematic diagram of a battery device provided in some embodiments of this application; Figure 5 for Figure 4 A cross-sectional view along the AA direction; Figure 6 for Figure 5 An enlarged view of box A; Figure 7 This is an exploded view of a portion of the structure of a battery cell provided in some embodiments of this application; Figure 8 A schematic diagram of the structure of the positive terminal of a battery cell provided in some embodiments of this application; Figure 9 for Figure 8 The diagram shows an explosion of the positive terminal.

[0167] Reference Figures 4 to 9This application provides a battery cell 6, which includes a housing 20, an electrode assembly 10, and a terminal portion 50. The housing 20 includes a wall portion 21. The electrode assembly 10 is housed within the housing 20 and includes an electrode body 11 and tabs 12 extending from the electrode body 11. The terminal portion 50 is located on the side of the wall portion 21 facing away from the electrode body 11. The terminal portion 50 has a base region 50a and a thinning region 50b. The maximum thickness of the thinning region 50b is less than the maximum thickness of the base region 50a. Along the direction from the electrode body 11 to the wall portion 21, a portion of the base region 50a protrudes from the surface of the thinning region 50b facing away from the wall portion 21.

[0168] The wall portion 21 can be an end cap 20b or a wall of the housing 20a.

[0169] There can be one electrode assembly 10 or multiple electrode assemblies.

[0170] As an example, the electrode body 11 includes a positive electrode active material layer, a region of the positive electrode current collector covered by the positive electrode active material layer, a negative electrode active material layer, a region of the negative electrode current collector covered by the negative electrode active material layer, and an insulating element. The electrode assembly 10 includes a positive electrode tab 12a and a negative electrode tab 12b.

[0171] There may be one or more terminal portions 50.

[0172] In some examples, there are multiple terminal portions 50, each including a positive terminal portion 501 and a negative terminal portion 502. The positive terminal portion 501 is electrically connected to the positive tab 12a, and the negative terminal portion 502 is electrically connected to the negative tab 12b. There may be one or more positive terminal portions 501; there may be one or more negative terminal portions 502.

[0173] In other examples, there may be only one terminal portion 50. For example, one of the positive tab 12a and the negative tab 12b is electrically connected to the terminal portion 50, and the other is electrically connected to the wall portion 21 of the housing 20.

[0174] Terminal 50 can be directly connected to tab 12 to achieve electrical connection between terminal 50 and tab 12; alternatively, terminal 50 can be indirectly connected to tab 12 through other conductive structures to achieve electrical connection between terminal 50 and tab 12.

[0175] Exemplarily, the terminal portion 50 may form at least a portion of the electrode terminal 30. In some examples, the electrode terminal 30 includes only the terminal portion 50, i.e., the entire electrode terminal 30 is located outside the wall portion 21. In other examples, the electrode terminal 30 also includes other portions, for example, the wall portion 21 includes a through electrode lead-out hole, and the electrode terminal 30 also includes a portion received in the electrode lead-out hole.

[0176] There can be one or more substrate regions 50a. In some examples, there is one substrate region 50a; in other examples, there are multiple substrate regions 50a, and the thinning region 50b connects two adjacent substrate regions 50a.

[0177] There can be one or more thinning regions 50b. In some examples, there is one thinning region 50b; in other examples, there are multiple thinning regions 50b, and the matrix region 50a connects two adjacent thinning regions 50b.

[0178] As an example, in the thickness direction Z of the wall portion 21, a portion of the wall portion 21 may be located between the terminal portion 50 and the electrode body 11.

[0179] As an example, the direction in which the electrode body 11 points to the wall portion 21 is parallel to the thickness direction Z of the wall portion 21, and the direction in which the wall portion 21 points to the electrode body 11 is parallel to the thickness direction Z of the wall portion 21.

[0180] Along the direction from the wall portion 21 to the electrode body 11, the substrate region 50a may protrude from the surface of the thinning region 50b facing the wall portion 21, or it may not protrude from the surface of the thinning region 50b facing the wall portion 21. Along the direction from the wall portion 21 to the electrode body 11, the thinning region 50b may protrude from the surface of the substrate region 50a facing the wall portion 21, or it may not protrude from the surface of the substrate region 50a facing the wall portion 21.

[0181] At least a portion of the thickness of the matrix region 50a is greater than the maximum thickness of the thinning region 50b.

[0182] In this embodiment, by providing a thinning region 50b, installation space for the busbar component 7 can be provided on the side of the thinning region 50b facing away from the wall 21, thereby improving space utilization. Providing the thinning region 50b also reduces the volume and weight of the battery cell 6, increasing its energy density.

[0183] In some embodiments, the terminal portion 50 includes a first conductive portion 51 and a second conductive portion 52, both of which are electrically connected to the tab 12. The melting point of the second conductive portion 52 is higher than that of the first conductive portion 51. At least a portion of the first conductive portion 51 and at least a portion of the second conductive portion 52 are formed in the thinning region 50b. In the thinning region 50b, at least a portion of the second conductive portion 52 is located between the first conductive portion 51 and the wall portion 21.

[0184] The first conductive portion 51 may be entirely formed in the thinning region 50b, or it may be only partially formed in the thinning region 50b. For example, a portion of the first conductive portion 51 is formed in the thinning region 50b, and another portion is formed in the substrate region 50a.

[0185] The second conductive portion 52 may be formed entirely in the thinning region 50b, or it may be formed only partially in the thinning region 50b. For example, a portion of the second conductive portion 52 is formed in the thinning region 50b, and another portion is formed in the substrate region 50a.

[0186] In the thinning region 50b, the second conductive portion 52 may be entirely located between the first conductive portion 51 and the wall portion 21. Alternatively, in the thinning region 50b, a portion of the second conductive portion 52 may be located between the first conductive portion 51 and the wall portion 21.

[0187] For example, the melting point of the first conductive part 51 is the melting point of the material of the first conductive part 51, and the melting point of the second conductive part 52 is the melting point of the material of the second conductive part 52.

[0188] When welding the busbar component 7 and the thinning region 50b, the second conductive part 52, which has a higher melting point, is less likely to be melted through, thereby reducing the risk of damage to other components of the battery cell 6 and improving the reliability of the battery cell 6.

[0189] By providing the second conductive part 52, the required thickness of the thinning region 50b can be reduced, thereby saving space.

[0190] In some embodiments, the melting point of the second conductive part 52 is greater than or equal to 800°C.

[0191] As an example, the melting point of the second conductive part 52 may be 800°C, 900°C, 1000°C, 1100°C, 1200°C or 1300°C.

[0192] The embodiments of this application can reduce the risk of the second conductive part 52 being soldered through.

[0193] In some embodiments, the material of the first conductive portion 51 may be a metal. The material of the first conductive portion 51 may be a single metal or an alloy.

[0194] In some embodiments, the material of the second conductive portion 52 can be a metal or a non-metal. For example, the material of the second conductive portion 52 can be a single metal or an alloy.

[0195] In some embodiments, the first conductive portion 51 is made of an alloy, and the second conductive portion 52 is made of an alloy. The base metal of the first conductive portion 51 and the base metal of the second conductive portion 52 may be the same or different. The melting point of the alloy can be changed by adjusting its composition and proportion.

[0196] In some embodiments, the first conductive part 51 is made of aluminum or an aluminum alloy. Aluminum and aluminum alloys have good thermal conductivity, and the aluminum first conductive part 51 can dissipate heat quickly during welding, reducing local overheating. Aluminum and aluminum alloys also have good electrical conductivity and corrosion resistance. Using an aluminum first conductive part 51 can reduce resistance and reduce heat generation in the terminal part 50 during charging and discharging.

[0197] In some embodiments, the second conductive portion 52 is made of copper or a copper alloy. Copper and copper alloys have high melting points, and using a copper second conductive portion 52 can reduce the risk of the second conductive portion 52 being soldered through, thereby improving the reliability of the battery cell 6. Copper has high electrical conductivity, and using a copper second conductive portion 52 can reduce the resistance of the terminal portion 50.

[0198] Compared to copper, aluminum has a lower melting point. Using an aluminum first conductive part 51 can reduce welding power and welding heat generation. Compared to aluminum, copper has a higher melting point. Using a copper second conductive part 52 can reduce the risk of the thinned region 50b being melted through, thus improving the reliability of the battery cell 6.

[0199] In some embodiments, the first conductive portion 51 and the second conductive portion 52 are connected by rolling, hot pressing or other means.

[0200] In some embodiments, the second conductive portion 52 and the first conductive portion 51 form a copper-aluminum composite plate.

[0201] In some embodiments, the maximum thickness of the substrate region 50a is T1, the maximum thickness of the thinning region 50b is T2, and 0.4≤T2 / T1≤0.9.

[0202] As an example, T2 / T1 can be 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9.

[0203] For example, the thickness direction of the substrate region 50a, the thickness direction of the thinning region 50b, and the thickness direction Z of the wall portion 21 are parallel to each other.

[0204] In this embodiment, T2 / T1 is set to be greater than or equal to 0.4, which can reduce the risk of the thinned region 50b being melted through during welding; in this embodiment, T2 / T1 is set to be less than or equal to 0.9, which can provide more space for the busbar component 7 and improve space utilization.

[0205] In some embodiments, the thickness of the thinning region 50b is 1mm-2.5mm.

[0206] For example, the thinning region 50b can be a plate-like structure with a uniform thickness, and the thickness of the thinning region 50b can be 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm or 2.5 mm.

[0207] For example, the thinning region 50b can be a plate-like structure with non-uniform thickness. The minimum thickness of the thinning region 50b is greater than or equal to 1 mm, and the maximum thickness of the thinning region 50b is less than or equal to 2.5 mm.

[0208] In this embodiment, the thickness of the thinning region 50b is set to be greater than or equal to 1 mm to reduce the risk of the thinning region 50b being soldered through. In another embodiment, the thickness of the thinning region 50b is set to be less than or equal to 2.5 mm to reduce the space and weight occupied by the thinning region 50b and improve the energy density of the battery cell 6.

[0209] In some embodiments, the substrate region 50a may be a plate-like structure with uniform thickness.

[0210] In some embodiments, in the thinning region 50b, the minimum thickness of the first conductive portion 51 is T3, the minimum thickness of the second conductive portion 52 is T4, and 0.2≤T4 / T3≤0.8.

[0211] As an example, T4 / T3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0212] In this embodiment, setting T4 / T3 to be greater than or equal to 0.2 can reduce the risk of the second conductive part 52 being melted through; in this embodiment, setting T4 / T3 to be less than or equal to 0.8 can make the first conductive part 51 have a higher thickness, thereby improving the welding strength and current carrying capacity between the first conductive part 51 and the bus component 7.

[0213] In some embodiments, T3 is 0.5mm-2mm. Exemplarily, T3 is 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm or 2mm.

[0214] In some embodiments, T4 is 0.2mm-1mm. Exemplarily, T4 is 0.2mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm or 1mm.

[0215] In some embodiments, the conductivity of the second conductive portion 52 is higher than that of the first conductive portion 51.

[0216] In some embodiments, the battery cell 6 is a prismatic battery cell.

[0217] In some embodiments, the substrate region 50a and the thinning region 50b are arranged along the length direction X of the wall portion 21. The thinning region 50b may have a larger size in the length direction X of the wall portion 21, thereby increasing the welding area between the thinning region 50b and the busbar component 7 and improving the flow capacity.

[0218] In some embodiments, the dimension of the thinning region 50b along the length direction X is greater than or equal to the dimension of the base region 50a along the length direction X. Compared to the base region 50a, the thinning region 50b can have a larger length, thereby making full use of the space on the upper side of the wall portion 21 and increasing the welding area between the thinning region 50b and the busbar component 7.

[0219] In some embodiments, the ratio of the dimension of the thinning region 50b along the length direction X to the dimension of the substrate region 50a along the length direction X is 1.5-4.

[0220] In some embodiments, the wall portion 21 is provided with an electrode lead-out hole 211. Exemplarily, the electrode lead-out hole 211 extends through the wall portion 21 along the thickness direction Z.

[0221] In some embodiments, the battery cell 6 further includes an electrode post 60, which includes a first portion 61 and a second portion 62 connected to each other. The first portion 61 is located on the side of the wall 21 facing the electrode assembly 10 and is electrically connected to the tab 12. In the thickness direction Z of the wall 21, a portion of the wall 21 is located between the base region 50a and the first portion 61, and at least a portion of the second portion 62 is accommodated in the electrode lead-out hole 211, and the second portion 62 is connected to the base region 50a.

[0222] In some examples, the second part 62 is separate from the base region 50a, and the two can be fixedly connected by welding, riveting or other means; alternatively, the second part 62 and the base region 50a are integrally formed.

[0223] In some examples, the second part 62 is integrally formed with the first part 61. Alternatively, the second part 62 and the first part 61 are separate parts, which can be fixedly connected by welding, riveting or other means.

[0224] In this embodiment, the substrate region 50a and the first portion 61 can clamp the wall portion 21 from both sides, thereby fixing the terminal portion 50 and the pole post 60 to the wall portion 21. Compared to the thinned region 50b, the substrate region 50a has a larger thickness. Connecting the second portion 62 to the substrate region 50a can increase the connection strength and improve the stability of the terminal portion 50.

[0225] In some embodiments, the pole post 60 is a one-piece molded structure.

[0226] In some embodiments, the second portion 62 is riveted to the base region 50a.

[0227] In some embodiments, the base region 50a has a through hole 50c, a portion of the second portion 62 is accommodated in the through hole 50c and connected to the base region 50a. Optionally, the through hole 50c is a stepped hole that is larger on the outside and smaller on the inside.

[0228] In some embodiments, the electrode terminal 30 includes a post 60 and a terminal portion 50.

[0229] In some embodiments, the material of the electrode post 60 is the same as the material of the tab 12. As an example, the positive tab 12a is aluminum foil, and the material of the positive electrode post 60 is aluminum or an aluminum alloy. The negative tab 12b is copper foil, and the material of the negative electrode post 60 is copper or a copper alloy.

[0230] In some embodiments, the battery cell 6 includes a first insulating member 70, at least a portion of which is disposed between the wall portion 21 and the terminal portion 50. The first insulating member 70 can be used to insulate and isolate the wall portion 21 from the terminal portion 50.

[0231] In some embodiments, the battery cell 6 further includes a second insulating member 80, at least a portion of which is located between the wall portion 21 and the electrode body 11.

[0232] In some embodiments, the second insulating member 80 abuts against the electrode body 11 along the thickness direction Z of the wall portion 21. When the battery cell 6 is subjected to external impact, the second insulating member 80 can abut against the electrode body 11, reducing the vibration amplitude of the electrode body 11.

[0233] In some embodiments, a portion of the second insulating member 80 is located between the wall portion 21 and the first portion 61.

[0234] In some embodiments, the battery cell 6 further includes a seal 90. The seal 90 may surround the second portion 62, and at least a portion of the seal 90 is sandwiched between the wall portion 21 and the first portion 61 in the thickness direction Z of the wall portion 21. The seal 90 is used to seal the electrode lead-out hole 211 from the inside of the wall portion 21.

[0235] In some embodiments, the first conductive portion 51 includes a first base 511 and a first extension 512 connected to the first base 511. Along the direction from the electrode body 11 toward the wall portion 21, a portion of the first base 511 protrudes from the surface of the first extension 512 facing away from the wall portion 21. The first base 511 is formed in the substrate region 50a, and the first extension 512 is formed in the thinning region 50b. The first base 511 is electrically connected to the tab 12 and the first extension 512. In the thickness direction Z of the wall portion 21, at least a portion of the second conductive portion 52 is located between the first extension 512 and the wall portion 21.

[0236] Along the direction from the wall portion 21 toward the electrode body 11, the second conductive portion 52 may protrude from the end face of the first base portion 511 facing the wall portion 21, or it may not protrude from the end face of the first base portion 511 facing the wall portion 21.

[0237] In the thickness direction Z of the wall portion 21, the second conductive portion 52 may be entirely located between the first extension portion 512 and the wall portion 21. Alternatively, in the thickness direction Z of the wall portion 21, a portion of the second conductive portion 52 may be located between the first extension portion 512 and the wall portion 21, and another portion of the second conductive portion 52 may be located between the first base portion 511 and the wall portion 21.

[0238] In some examples, the base region 50a includes only the first base 511. In other examples, the base region 50a may also include other portions.

[0239] The first extension 512 can be used to weld to the busbar component 7. The first base 511 can electrically connect the tab 12 to the first extension 512, thereby reducing the current flowing through the contact surface between the second conductive part 52 and the first conductive part 51 during the charging and discharging of the battery cell 6, reducing resistance, and shortening the conductive path.

[0240] In addition, this application has a low requirement for the current carrying capacity of the second conductive part 52, and the second conductive part 52 can have a small thickness, for example, the thickness of the second conductive part 52 can be less than or equal to 1 mm.

[0241] In some embodiments, the second conductive portion 52 is a flat plate structure with uniform thickness.

[0242] In some embodiments, the first base 511 has a first end face 511a facing away from the wall portion 21.

[0243] The first end face 511a may be the surface of the first base 511 that is furthest from the wall portion 21 in the thickness direction Z. For example, the first end face 511a is a plane.

[0244] In some embodiments, the first conductive portion 51 has a first recess 513 on the side opposite to the wall portion 21 along the thickness direction Z. The first recess 513 is recessed relative to the first end face 511a, and the first extension portion 512 corresponds to the bottom surface 513a of the first recess.

[0245] For example, in the same plane perpendicular to the thickness direction Z of the wall portion 21, the orthographic projection of the first extension portion 512 coincides with the orthographic projection of the bottom surface 513a of the first recess.

[0246] The first recess 513 can be used to accommodate a part of the busbar component 7, reducing the space occupied by the terminal portion 50 and the busbar component 7 in the thickness direction Z of the wall portion 21, and improving space utilization.

[0247] In some embodiments, the bottom surface 513a of the first recess is a plane.

[0248] In some embodiments, the first recess 513 extends through the first conductive portion 51 along the width direction Y of the wall portion 21.

[0249] In some embodiments, along the length direction X of the wall portion 21, the first recess 513 extends to one end of the first conductive portion 51.

[0250] In some embodiments, the area of ​​the orthographic projection of the first base 511 along the thickness direction Z is S1, the area of ​​the first end face 511a is S2, and 0.3≤S2 / S1≤1.

[0251] In some embodiments, the first base 511 has a second end face 511b facing the wall portion 21.

[0252] The second end face 511b can be the surface of the first base 511 that is closest to the wall portion 21 in the thickness direction Z. As an example, the second end face 511b is a plane.

[0253] For example, the distance between the first end face 511a and the second end face 511b in the thickness direction Z can be equal to the maximum thickness T1 of the base region 50a.

[0254] The surface of the first extension 512 facing the wall portion 21 may or may not be flush with the second end face 511b.

[0255] The surface of the second conductive part 52 facing the wall part 21 may or may not be flush with the second end face 511b.

[0256] In some embodiments, the area of ​​the second end face 511b is S3. 0.3≤S3 / S1≤1.

[0257] In some embodiments, the first conductive portion 51 has a second recess 514 on the side of the wall portion 21 along the thickness direction Z. The second recess 514 is recessed relative to the second end face 511b, and at least a portion of the first extension portion 512 is formed between the second recess 514 and the first recess 513. At least a portion of the second conductive portion 52 is accommodated in the second recess 514.

[0258] In some examples, in the same plane perpendicular to the thickness direction Z, the orthographic projection of the bottom surface 514a of the second recess is located within the orthographic projection of the bottom surface 513a of the first recess, and the area of ​​the orthographic projection of the bottom surface 514a of the second recess is smaller than the area of ​​the orthographic projection of the bottom surface 513a of the first recess; at this time, a portion of the first extension 512 is formed between the second recess 514 and the first recess 513.

[0259] In other examples, in the same plane perpendicular to the thickness direction Z, the orthographic projection of the bottom surface 513a of the first recess is located within the orthographic projection of the bottom surface 514a of the second recess, and the area of ​​the orthographic projection of the bottom surface 514a of the second recess is greater than or equal to the area of ​​the orthographic projection of the bottom surface 513a of the first recess; in this case, the first extension 512 is integrally formed between the bottom surface 514a of the second recess and the bottom surface 513a of the first recess.

[0260] The second conductive part 52 can be entirely accommodated in the second recess 514, or it can be partially accommodated in the second recess 514.

[0261] In this embodiment of the application, by providing the second recess 514, the size of the second conductive part 52 protruding from the second end face 511b can be reduced, thereby reducing the space occupied by the terminal part 50 in the thickness direction Z and improving the space utilization rate.

[0262] In some embodiments, the bottom surface 514a of the second recess is a plane.

[0263] In some embodiments, the second recess 514 penetrates the first conductive portion 51 along the width direction Y of the wall portion 21.

[0264] In some embodiments, along the length direction X of the wall portion 21, the second recess 514 extends to one end of the first conductive portion 51.

[0265] In some embodiments, the first extension 512 is a flat plate structure with uniform thickness, and the thickness of the first extension 512 is equal to T3; the second conductive part 52 is a flat plate structure with uniform thickness, and the thickness of the second conductive part 52 is equal to T4. T2 = T3 + T4.

[0266] In some embodiments, the second conductive portion 52 is entirely housed within the second recess 514. The second conductive portion 52 and the first base portion 511 can share space in the thickness direction Z of the wall portion 21, thereby reducing the maximum size of the terminal portion 50 in the thickness direction Z and improving space utilization.

[0267] In some embodiments, the surface of the second conductive portion 52 facing the wall portion 21 is flush with the second end face 511b.

[0268] For example, in the thickness direction Z of the wall portion 21, the depth of the second recess 514 is equal to the thickness of the second conductive portion 52.

[0269] The embodiments of this application can improve the flatness of the side of the terminal portion 50 facing the wall portion 21 and simplify the structure of the components of the battery cell 6 that contact the terminal portion 50.

[0270] In some embodiments, the second conductive portion 52 fills the second recess 514.

[0271] In some embodiments, the orthographic projection of the first extension 512 lies within the orthographic projection of the second conductive portion 52 in the same plane perpendicular to the thickness direction Z.

[0272] In this embodiment, the second conductive portion 52 can completely separate the first extension portion 512 from the wall portion 21, thereby reducing the risk of the thinned region 50b being welded through when welding the busbar component 7 and the first extension portion 512.

[0273] In some embodiments, a third recess 212 is provided on the side of the wall portion 21 facing the terminal portion 50, and the orthographic projection of the terminal portion 50 is located in the orthographic projection of the third recess 212 in the same plane perpendicular to the thickness direction Z of the wall portion 21.

[0274] By providing the third recess 212, the height of the terminal portion 50 protruding from the outer surface of the wall portion 21 can be reduced, thereby improving space utilization and increasing the energy density of the battery cell 6.

[0275] In some embodiments, at least a portion of the first insulating member 70 is accommodated in the third recess 212.

[0276] In some embodiments, a portion of the terminal portion 50 is accommodated in the third recess 212. Alternatively, a portion of the second conductive portion 52 is accommodated in the third recess 212.

[0277] In some embodiments, the electrode assembly 10 includes a plurality of tabs 12, the plurality of tabs 12 including a positive tab 12a and a negative tab 12b. The battery cell 6 includes a plurality of terminal portions 50, the plurality of terminal portions 50 including a positive terminal portion 501 and a negative terminal portion 502, the positive terminal portion 501 being electrically connected to the positive tab 12a, and the negative terminal portion 502 being electrically connected to the negative tab 12b.

[0278] In some embodiments, the positive terminal portion 501 is composed of a first conductive portion 51 and a second conductive portion 52. Exemplarily, the positive terminal portion 501 is a copper-aluminum composite plate.

[0279] Figure 10 for Figure 5 Enlarged view at box C; Figure 11 A schematic diagram of the negative terminal portion of a battery cell provided in some embodiments of this application;

[0280] Reference Figure 10 and Figure 11In some embodiments, the first base 511 of the negative terminal portion 502 has a fourth recess 515 on the side facing away from the wall portion 21. The negative terminal portion 502 also includes a third conductive portion 53, at least a portion of which is accommodated in the fourth recess 515 and connected to the first base 511. The third conductive portion 53 forms part of the base region 50a. The third conductive portion 53 is electrically connected to the negative electrode tab 12b, and the material of the third conductive portion 53 is the same as the material of the negative electrode tab 12b.

[0281] By using a third conductive portion 53 and a negative electrode tab 12b made of the same material, the connection process between the third conductive portion 53 and the negative electrode tab 12b can be simplified, and the resistance between the negative terminal portion 502 and the negative electrode tab 12b can be reduced. The fourth recess 515 can accommodate at least a portion of the third conductive portion 53, thereby reducing the maximum dimension of the substrate region 50a in the thickness direction Z.

[0282] In some embodiments, the material of the third conductive portion 53 is the same as the material of the second conductive portion 52. This embodiment can reduce the number of material types, which is beneficial for reducing costs and simplifying the manufacturing process of the negative terminal portion 502.

[0283] In some embodiments, the negative terminal post 60 is connected to the third conductive part 53 and the negative electrode tab 12b.

[0284] The materials of the negative terminal post 60, the third conductive part 53, and the negative electrode tab 12b are the same.

[0285] In some embodiments, the third conductive portion 53 is entirely housed within the fourth recess 515.

[0286] In some embodiments, the surface of the third conductive portion 53 on the side opposite to the wall portion 21 along the thickness direction Z is flush with the first end face 511a.

[0287] In some embodiments, one end of the through hole 50c of the negative terminal portion 502 extends to the bottom surface of the fourth recess 515.

[0288] Figure 12 A partially enlarged schematic diagram of a battery cell provided for other embodiments of this application; Figure 13 for Figure 12 Enlarged view of the area within the circle; Figure 14 Exploded view of a portion of the structure of a battery cell provided in other embodiments of this application; Figure 15 for Figure 14 A schematic diagram of the positive terminal part is shown.

[0289] Reference Figures 12 to 15In some embodiments, a third recess 212 is provided on the side of the wall portion 21 facing the terminal portion 50. In the same plane perpendicular to the thickness direction Z of the wall portion 21, the orthographic projection of the terminal portion 50 lies within the orthographic projection of the third recess 212. The third recess 212 includes a first sub-recess 2121 and a second sub-recess 2122 that are interconnected. In the thickness direction Z, the depth of the second sub-recess 2122 is greater than the depth of the first sub-recess 2121. In the same plane perpendicular to the thickness direction Z, the orthographic projection of the thinning region 50b at least partially overlaps with the orthographic projection of the second sub-recess 2122.

[0290] Along the direction from the terminal portion 50 to the wall portion 21, the thinning region 50b may protrude from the substrate region 50a or may not protrude from the substrate region 50a.

[0291] In this embodiment, by providing a second sub-recess 2122 with a greater depth, the distance between the wall portion 21 and the thinning region 50b can be increased, providing installation space for other components.

[0292] In some embodiments, a portion of the first insulating member 70 is accommodated in the second sub-recess 2122 and located between the thinning region 50b and the wall portion 21. By providing the second sub-recess 2122, the thickness of the first insulating member 70 can be increased, thereby reducing the risk of the first insulating member 70 failing due to high temperature when welding the thinning region 50b and the busbar 7.

[0293] In some embodiments, a portion of the second conductive portion 52 protrudes from the second end face 511b in the direction from the terminal portion 50 to the wall portion 21.

[0294] Given a fixed thickness of the second conductive portion 52, by setting a portion of the second conductive portion 52 to protrude from the second end face 511b, the requirement for the depth of the second recess 514 can be reduced. Correspondingly, when the depth of the second recess 514 is reduced, the depth of the first recess 513 can be increased, thereby providing more installation space for the busbar component 7.

[0295] In some embodiments, the first extension 512 includes a first sub-part 5121 and a second sub-part 5122, the thickness of the first sub-part 5121 being less than the thickness of the second sub-part 5122, and the second sub-part 5122 connecting the first sub-part 5121 and the first base 511. In the thickness direction Z, the first sub-part 5121 is stacked with the first conductive part 51.

[0296] The second recess 514 is recessed from the surface of the second sub-part 5122 toward the wall part 21, and the first sub-part 5121 corresponds to the bottom surface 514a of the second recess.

[0297] The sum of the thickness of the first sub-part 5121 and the thickness of the second conductive part 52 is greater than the thickness of the second sub-part 5122.

[0298] The sum of the thickness of the first sub-part 5121 and the thickness of the second conductive part 52 is equal to T2.

[0299] The thickness of the first sub-part 5121 is equal to T3.

[0300] In some embodiments, the depth of the first recess 513 is greater than the depth of the second recess 514 in the thickness direction Z of the wall portion 21.

[0301] In some embodiments, a third recess 212 is provided on the side of the wall portion 21 facing the terminal portion 50. In the same plane perpendicular to the thickness direction Z, the orthographic projection of the terminal portion 50 lies within the orthographic projection of the third recess 212. The third recess 212 includes a first sub-recess 2121 and a second sub-recess 2122 that are connected to each other. In the thickness direction Z, the depth of the second sub-recess 2122 is greater than the depth of the first sub-recess 2121. In the same plane perpendicular to the thickness direction Z, the orthographic projection of the second conductive portion 52 lies within the orthographic projection of the second sub-recess 2122.

[0302] By providing a deeper second sub-recess 2122, the distance between the wall portion 21 and the second conductive portion 52 can be increased, providing installation space for other components.

[0303] In some embodiments, a portion of the first insulating member 70 is accommodated in the second sub-recess 2122 and is located between the second conductive portion 52 and the wall portion 21.

[0304] In some embodiments, the portion of the wall 21 corresponding to the second sub-recess 2122 protrudes toward the electrode body 11.

[0305] For example, along the direction from the wall portion 21 to the electrode body 11, the bottom wall of the second sub-recess 2122 protrudes from the bottom wall of the first sub-recess 2121.

[0306] This application can reduce the impact of setting the second sub-recess 2122 on the thickness of the wall portion 21.

[0307] In some embodiments, along the direction of the wall portion 21 toward the electrode body 11, the portion of the first insulating member 70 that is accommodated in the second sub-recess 2122 protrudes beyond the portion of the first insulating member 70 that is accommodated in the first sub-recess 2121.

[0308] In some embodiments, the second insulating member 80 has an insulating recess on the side facing the wall portion 21, which can be used to accommodate at least a portion of the bottom wall of the second sub-recess 2122.

[0309] In some embodiments, a portion of the second conductive portion 52 is accommodated in the second sub-recess 2122. Embodiments of this application can improve space utilization.

[0310] Figure 16 A partial cross-sectional schematic diagram of a battery cell provided for some embodiments of this application; Figure 17 An exploded view of a portion of the structure of a battery cell provided in some embodiments of this application; Figure 18 for Figure 17 The diagram shows the negative terminal part.

[0311] Reference Figures 16 to 18 In some embodiments, the second conductive portion 52 includes a second base 521 and a second extension 522 connected to the second base 521. At least a portion of the second base 521 is formed in the substrate region 50a, and the second extension 522 is formed in the thinning region 50b. The second base 521 is electrically connected to the tab 12 and the second extension 522. In the thickness direction Z of the wall portion 21, the second extension 522 is located between the first conductive portion 51 and the wall portion 21. Along the direction from the electrode body 11 to the wall portion 21, a portion of the second base 521 protrudes from the surface of the first conductive portion 51 facing away from the wall portion 21.

[0312] Along the direction from the wall portion 21 toward the electrode body 11, the second extension portion 522 may protrude from the end face of the second base portion 521 facing the wall portion 21, or it may not protrude from the end face of the second base portion 521 facing the wall portion 21.

[0313] In some examples, the matrix region 50a includes only the second base 521. In other examples, the matrix region 50a may also include other portions.

[0314] The first conductive part 51 can be soldered to the busbar component 7.

[0315] In this embodiment, at least a portion of the second base 521 is formed in the substrate region 50a, which can improve the high temperature resistance of the substrate region 50a.

[0316] In some embodiments, the conductivity of the second conductive portion 52 is higher than that of the first conductive portion 51; by disposing at least a portion of the second base portion 521 in the base region 50a, the resistance of the terminal portion 50 can be reduced.

[0317] In some embodiments, the second base 521 has a third end face 521a facing away from the wall portion 21.

[0318] The third end face 521a may be the surface of the second base 521 that is furthest from the wall portion 21 in the thickness direction Z. For example, the third end face 521a is a plane.

[0319] In some embodiments, the second conductive portion 52 has a fifth recess 523 recessed from the third end face 521a toward the wall portion 21, and the second extension portion 522 corresponds to the bottom surface 523a of the fifth recess. The first conductive portion 51 is accommodated in the fifth recess 523. In the thickness direction Z, the depth of the fifth recess 523 is greater than the thickness of the first conductive portion 51.

[0320] For example, in the same plane perpendicular to the thickness direction Z of the wall portion 21, the orthographic projection of the second extension portion 522 coincides with the orthographic projection of the bottom surface 523a of the fifth recess.

[0321] The fifth recess 523 can be used to accommodate a part of the busbar component 7, reducing the space occupied by the terminal portion 50 and the busbar component 7 in the thickness direction Z of the wall portion 21, and improving space utilization.

[0322] In some embodiments, the bottom surface 523a of the fifth recess is a plane.

[0323] In some embodiments, the orthographic projection of the second extension 522 and the orthographic projection of the first conductive portion 51 completely overlap in the same plane perpendicular to the thickness direction Z of the wall portion 21.

[0324] In some embodiments, the fifth recess 523 penetrates the second conductive portion 52 along the width direction Y of the wall portion 21.

[0325] In some embodiments, along the length direction X of the wall portion 21, the fifth recess 523 extends to one end of the second conductive portion 52.

[0326] In some embodiments, the fifth recess 523 has a stepped surface 523b. Optionally, the surface of the first conductive portion 51 facing away from the second extension 522 is flush with the stepped surface 523b of the fifth recess 523.

[0327] In some embodiments, the portion of the first base 511 corresponding to the step surface 523b along the thickness direction Z is formed in the thinning region 50b.

[0328] In some embodiments, the first conductive portion 51 is a flat plate structure with uniform thickness. The thickness of the first conductive portion 51 may be equal to T3.

[0329] In some embodiments, the second extension 522 is a flat plate structure with uniform thickness. The thickness of the second extension 522 may be equal to T4.

[0330] For example, T2 = T3 + T4.

[0331] In some embodiments, the second base 521 has a sixth recess 524 on the side facing the wall portion 21.

[0332] By providing a sixth recess 524, this application can reduce the volume and weight of the second base 521, thereby increasing the energy density of the battery cell 6. The sixth recess 524 can also provide space for other components of the battery cell 6, thus improving space utilization.

[0333] In some embodiments, at least a portion of the second extension 522 protrudes from the bottom surface 524a of the sixth recess along the direction from the terminal portion 50 to the wall portion 21.

[0334] With the thickness of the second extension 522 and the thickness of the first conductive part 51 being constant, setting a portion of the second extension 522 to protrude from the bottom surface 524a of the sixth recess can increase the depth of the fifth recess 523 and provide more installation space for the busbar component 7.

[0335] In some embodiments, the bottom surface 524a of the sixth recess is a plane.

[0336] In some embodiments, a third recess 212 is provided on the side of the wall portion 21 facing the terminal portion 50. In the same plane perpendicular to the thickness direction Z, the orthographic projection of the terminal portion 50 is located within the third recess 212. The third recess 212 includes a first sub-recess 2121 and a second sub-recess 2122 that are connected to each other. In the thickness direction Z, the depth of the second sub-recess 2122 is greater than the depth of the first sub-recess 2121. In the same plane perpendicular to the thickness direction Z, the orthographic projection of the second extension 522 is located within the orthographic projection of the second sub-recess 2122, and the orthographic projection of the bottom surface 524a of the sixth recess is located within the orthographic projection of the first sub-recess 2121.

[0337] By providing a deeper second recess 2122, the distance between the wall portion 21 and the second extension portion 522 can be increased, providing installation space for other components.

[0338] In some embodiments, a portion of the first insulating member 70 is accommodated in the second sub-recess 2122 and is located between the second extension 522 and the wall portion 21.

[0339] In some embodiments, in the same plane perpendicular to the thickness direction Z, the orthographic projection of the bottom surface 523a of the fifth recess does not overlap with the orthographic projection of the bottom surface 524a of the sixth recess.

[0340] In some embodiments, the distance between the third end face 521a and the bottom face 524a of the sixth recess in the thickness direction Z may be equal to T1.

[0341] In some embodiments, along the direction from the wall portion 21 to the terminal portion 50, the second base portion 521 protrudes from the surface of the first conductive portion 51 away from the wall portion 21 by a height of H1, and the sixth recess portion 524 has a depth of H2; H1 is greater than H2.

[0342] In some embodiments, the electrode assembly 10 includes a plurality of tabs 12, which include a positive tab 12a and a negative tab 12b. The battery cell 6 includes a plurality of terminal portions 50, which include a positive terminal portion 501 and a negative terminal portion 502. The positive terminal portion 501 is electrically connected to the positive tab 12a, and the negative terminal portion 502 is electrically connected to the negative tab 12b. The material of the second conductive portion 52 of the negative terminal portion 502 is the same as the material of the negative tab 12b.

[0343] By setting the second conductive part 52 and the negative electrode tab 12b to be made of the same material, the connection process between the second conductive part 52 and the negative electrode tab 12b can be simplified, and the resistance between the negative terminal part 502 and the negative electrode tab 12b can be reduced.

[0344] For example, compared to Figure 11 The negative terminal portion 502 shown in this embodiment can omit the third conductive portion 53.

[0345] In some embodiments, the negative terminal post 60 is riveted to the second conductive part 52.

[0346] In some embodiments, the second conductive portion 52 of the negative terminal portion 502 includes a second base portion 521 and a second extension portion 522 connected to the second base portion 521. In the thickness direction Z of the wall portion 21, the second extension portion 522 is located between the first conductive portion 51 and the wall portion 21.

[0347] The first conductive portion 51 of the positive terminal portion 501 includes a first base portion 511 and a first extension portion 512 connected to the first base portion 511. In the thickness direction Z of the wall portion 21, at least a portion of the second conductive portion 52 is located between the first extension portion 512 and the wall portion 21.

[0348] The first conductive part 51 of the positive terminal 501 and the first conductive part 51 of the negative terminal 502 may adopt different structures, and the second conductive part 52 of the positive terminal 501 and the second conductive part 52 of the negative terminal 502 may adopt different structures.

[0349] Re-reference Figures 4 to 6 This application also provides a battery device, which includes the battery cell 6 provided in any of the foregoing embodiments.

[0350] In some embodiments, the battery device 2 includes a busbar 7, a portion of which is located on the side of the thinning region 50b facing away from the wall portion 21 and connected to the thinning region 50b.

[0351] Along the direction from the wall portion 21 to the terminal portion 50, the bus member 7 may protrude from the surface of the base region 50a away from the wall portion 21, or it may not protrude from the surface of the base region 50a away from the wall portion 21.

[0352] By providing a thinning zone 50b, the total space occupied by the busbar 7 and the terminal portion 50 in the thickness direction Z of the wall portion 21 can be reduced, thereby improving space utilization.

[0353] In some embodiments, the bus member 7 is welded to the first conductive portion 51 located in the thinning region 50b to form a welded portion W. In the same plane perpendicular to the thickness direction Z of the wall portion 21, the orthographic projection of the welded portion W is located within the orthographic projection of the second conductive portion 52.

[0354] When welding the busbar component 7 and the thinning region 50b, the second conductive part 52, which has a higher melting point, is less likely to be melted through, thereby reducing the risk of damage to other components of the battery cell 6 and improving the reliability of the battery cell 6.

[0355] In some embodiments, the welded portion W is spaced apart from the second conductive portion 52 in the thickness direction Z.

[0356] The embodiments of this application can reduce the risk of local melting of the second conductive part 52 and reduce the impact on the connection interface between the first conductive part 51 and the second conductive part 52.

[0357] In other embodiments, a portion of the weld portion W is formed on the second conductive portion 52. During welding, a portion of the busbar, a portion of the first conductive portion, and a portion of the second conductive portion 52 melt and form a molten pool, which solidifies to form the weld portion. In the thickness direction, a portion of the second conductive portion is located on the side of the weld portion facing the wall.

[0358] In some embodiments, along the direction from the electrode body 11 to the wall portion 21, the height of the substrate region 50a protruding from the surface of the thinning region 50b facing away from the wall portion 21 is H3, and the thickness of the busbar 7 is H4, where H3 is greater than or equal to H4. For example, as... Figure 15 As shown, along the direction from the terminal portion 50 to the wall portion 21, a portion of the second conductive portion 52 protrudes from the second end face 511b, the first recess may have a greater depth (the depth of the first recess may be equal to H3), and the thickness of the bus member 7 may be less than or equal to the depth of the first recess.

[0359] For example, the depth of the first recess 513 in the thickness direction Z is greater than the thickness of the busbar component 7.

[0360] In some embodiments, the busbar component 7 includes a busbar portion. In the same plane perpendicular to the thickness direction Z of the wall portion 21, the projection of the busbar portion lies within the projection of the thinning region 50b.

[0361] Along the direction from the wall portion 21 to the terminal portion 50, the bus portion does not protrude from the surface of the substrate region 50a facing away from the wall portion 21.

[0362] This application also provides an electrical device, including a battery cell 6 or a battery device 2 as described in any of the above embodiments. The battery cell 6 is used to provide electrical energy to the electrical device. The electrical device can be any of the aforementioned devices or systems that utilize the battery cell 6.

[0363] Reference Figures 4 to 9 This application provides a battery cell 6, which includes a housing 20, an electrode assembly 10, and a terminal portion 50. The housing 20 includes a shell 20a and an end cap 20b. The shell 20a has an opening, and the end cap 20b is connected to the shell 20a and covers the opening.

[0364] The electrode assembly 10 is housed within the housing 20. The electrode assembly 10 includes an electrode body 11 and tabs 12 extending from the electrode body 11.

[0365] The terminal portion 50 is located on the side of the end cap 20b facing away from the electrode body 11. The terminal portion 50 includes a first conductive portion 51 and a second conductive portion 52, both of which are electrically connected to the tab 12.

[0366] The first conductive portion 51 includes a first base 511 and a first extension 512 connected to the first base 511. The first base 511 has a first end face 511a facing away from the end cap 20b and a second end face 511b facing the end cap 20b.

[0367] The first conductive portion 51 has a first recess 513 and a second recess 514. The first recess 513 is recessed relative to the first end face 511a, and the second recess 514 is recessed relative to the second end face 511b. At least a portion of the first extension portion 512 is formed between the second recess 514 and the first recess 513.

[0368] At least a portion of the second conductive portion 52 is accommodated in the second recess 514.

[0369] The first recess 513 is used to receive a portion of the busbar component 7. The busbar component 7 is used to be welded to the first extension 512.

[0370] The melting point of the second conductive part 52 is higher than that of the first conductive part 51. For example, the material of the second conductive part 52 is copper or a copper alloy, and the material of the first conductive part 51 is aluminum or an aluminum alloy.

[0371] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0372] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: The outer casing, including the walls; An electrode assembly, housed within the housing, the electrode assembly comprising an electrode body and tabs extending from the electrode body; The terminal portion is located on the side of the wall portion facing away from the electrode body. The terminal portion has a substrate region and a thinning region. The maximum thickness of the thinning region is less than the maximum thickness of the substrate region. Along the direction from the electrode body to the wall portion, a portion of the substrate region protrudes from the surface of the thinning region facing away from the wall portion.

2. The battery cell according to claim 1, characterized in that, The terminal portion includes a first conductive portion and a second conductive portion, both of which are electrically connected to the tab. The melting point of the second conductive portion is higher than that of the first conductive portion. At least a portion of the first conductive portion and at least a portion of the second conductive portion are formed in the thinned region. In the thinning region, at least a portion of the second conductive portion is located between the first conductive portion and the wall portion.

3. The battery cell according to claim 2, characterized in that, The first conductive portion includes a first base and a first extension connected to the first base. In the direction from the electrode body to the wall portion, a portion of the first base protrudes from the surface of the first extension facing away from the wall portion. The first base portion is formed in the matrix region, and the first extension portion is formed in the thinned region; The first base portion is electrically connected to the electrode tab and the first extension portion; In the thickness direction of the wall portion, at least a portion of the second conductive portion is located between the first extension portion and the wall portion.

4. The battery cell according to claim 3, characterized in that, The first base portion has a first end face facing away from the wall portion; The first conductive portion has a first recess on the side opposite to the wall portion along the thickness direction. The first recess is recessed relative to the first end face, and the first extension portion corresponds to the bottom surface of the first recess.

5. The battery cell according to claim 4, characterized in that, The first base has a second end face facing the wall portion; The first conductive portion has a second recess on the side facing the wall portion along the thickness direction. The second recess is recessed relative to the second end face. At least a portion of the first extension portion is formed between the second recess and the first recess. At least a portion of the second conductive portion is accommodated in the second recess.

6. The battery cell according to claim 5, characterized in that, The second conductive portion is entirely accommodated within the second recess.

7. The battery cell according to claim 5, characterized in that, The surface of the second conductive portion facing the wall portion is flush with the second end face.

8. The battery cell according to claim 5, characterized in that, Along the direction from the terminal portion to the wall portion, a portion of the second conductive portion protrudes from the second end face.

9. The battery cell according to claim 8, characterized in that, A third recess is provided on the side of the wall facing the terminal portion, and in the same plane perpendicular to the thickness direction, the orthographic projection of the terminal portion is located within the orthographic projection of the third recess. The third recess includes a first sub-recess and a second sub-recess that are connected to each other, wherein in the thickness direction, the depth of the second sub-recess is greater than the depth of the first sub-recess; In the same plane perpendicular to the thickness direction, the orthographic projection of the second conductive portion lies within the orthographic projection of the second sub-recess.

10. The battery cell according to claim 9, characterized in that, A portion of the second conductive part is accommodated in the second sub-recess.

11. The battery cell according to claim 4, characterized in that, In the same plane perpendicular to the thickness direction, the orthographic projection of the first extension is located within the orthographic projection of the second conductive portion.

12. The battery cell according to claim 3, characterized in that, The electrode assembly includes a plurality of electrode tabs, and the plurality of electrode tabs includes a positive electrode tab and a negative electrode tab; The battery cell includes a plurality of terminal portions, each terminal portion including a positive terminal portion and a negative terminal portion, the positive terminal portion being electrically connected to the positive tab, and the negative terminal portion being electrically connected to the negative tab; The first base portion of the negative end portion is provided with a fourth recess on the side opposite to the wall portion; The negative terminal portion further includes a third conductive portion, at least partially housed in the fourth recess and connected to the first base portion; the third conductive portion forms a part of the base region; The third conductive part is electrically connected to the negative electrode tab, and the material of the third conductive part is the same as the material of the negative electrode tab.

13. The battery cell according to claim 12, characterized in that, The material of the third conductive part is the same as the material of the second conductive part.

14. The battery cell according to claim 2, characterized in that, The second conductive portion includes a second base and a second extension connected to the second base, wherein at least a portion of the second base is formed in the substrate region and the second extension is formed in the thinned region; The second base is electrically connected to the electrode tab and the second extension; In the thickness direction of the wall portion, the second extension is located between the first conductive portion and the wall portion; along the direction from the electrode body to the wall portion, a portion of the second base portion protrudes from the surface of the first conductive portion facing away from the wall portion.

15. The battery cell according to claim 14, characterized in that, The second base has a third end face facing away from the wall portion; The second conductive portion has a fifth recess that is recessed from the third end face into the wall portion, and the second extension portion corresponds to the bottom face of the fifth recess; The first conductive portion is accommodated in the fifth recess; in the thickness direction, the depth of the fifth recess is greater than the thickness of the first conductive portion.

16. The battery cell according to claim 14, characterized in that, The second base has a sixth recess on the side facing the wall. In the direction from the terminal portion to the wall portion, at least a portion of the second extension portion protrudes from the bottom surface of the sixth recess portion; A third recess is provided on the side of the wall facing the terminal portion, and the orthographic projection of the terminal portion is located in the third recess in the same plane perpendicular to the thickness direction; The third recess includes a first sub-recess and a second sub-recess that are connected to each other, wherein in the thickness direction, the depth of the second sub-recess is greater than the depth of the first sub-recess; In the same plane perpendicular to the thickness direction, the orthographic projection of the second extension is located within the orthographic projection of the second sub-recess, and the orthographic projection of the bottom surface of the sixth recess is located within the orthographic projection of the first sub-recess.

17. The battery cell according to claim 14, characterized in that, The electrode assembly includes a plurality of electrode tabs, and the plurality of electrode tabs includes a positive electrode tab and a negative electrode tab; The battery cell includes a plurality of terminal portions, each terminal portion including a positive terminal portion and a negative terminal portion, the positive terminal portion being electrically connected to the positive tab, and the negative terminal portion being electrically connected to the negative tab; The material of the second conductive part of the negative terminal is the same as the material of the negative electrode tab.

18. The battery cell according to any one of claims 2-17, characterized in that, The first conductive part is made of aluminum or an aluminum alloy, and the second conductive part is made of copper or a copper alloy.

19. The battery cell according to any one of claims 2-17, characterized in that, The melting point of the second conductive part is greater than or equal to 800°C.

20. The battery cell according to any one of claims 2-17, characterized in that, In the thinning region, the minimum thickness of the first conductive part is T3, the minimum thickness of the second conductive part is T4, and 0.2≤T4 / T3≤0.

8.

21. The battery cell according to any one of claims 1-17, characterized in that, The maximum thickness of the matrix region is T1, and the maximum thickness of the thinning region is T2, where 0.4 ≤ T2 / T1 ≤ 0.

9.

22. The battery cell according to any one of claims 1-17, characterized in that, The thickness of the thinned region is 1mm-2.5mm.

23. The battery cell according to any one of claims 1-17, characterized in that, The wall portion is provided with electrode lead-out holes; The battery cell further includes an electrode post, which includes a first part and a second part connected to each other. The first part is located on the side of the wall facing the electrode assembly and is electrically connected to the tab. In the thickness direction of the wall, a portion of the wall is located between the base region and the first part. At least a portion of the second part is accommodated in the electrode lead-out hole and is connected to the base region.

24. The battery cell according to any one of claims 1-17, characterized in that, A third recess is provided on the side of the wall portion facing the terminal portion. In the same plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the terminal portion is located within the orthographic projection of the third recess. The third recess includes a first sub-recess and a second sub-recess that are connected to each other, wherein in the thickness direction, the depth of the second sub-recess is greater than the depth of the first sub-recess; In the same plane perpendicular to the thickness direction, the orthographic projection of the thinned region at least partially overlaps with the orthographic projection of the second sub-recess.

25. The battery cell according to any one of claims 1-17, characterized in that, The matrix region and the thinning region are arranged along the length of the wall portion.

26. A battery device, characterized in that, include: The battery cell according to any one of claims 1-25; A busbar component, a portion of which is located on the side of the thinning region opposite to the wall and connected to the thinning region.

27. The battery device according to claim 26, characterized in that, The terminal portion includes a first conductive portion and a second conductive portion, both of which are electrically connected to the tab. The melting point of the second conductive portion is higher than that of the first conductive portion. At least a portion of the first conductive portion and at least a portion of the second conductive portion are formed in the thinned region. In the thinning region, at least a portion of the second conductive portion is located between the first conductive portion and the wall portion; The busbar component is welded to the first conductive part located in the thinning region to form a welded part. In the same plane perpendicular to the thickness direction of the wall, the orthographic projection of the welded part is located within the orthographic projection of the second conductive part.

28. The battery device according to claim 27, characterized in that, In the thickness direction, the welded portion and the second conductive portion are spaced apart.

29. An electrical appliance, characterized in that, Includes the battery device according to any one of claims 26-28, the battery device being used to provide electrical energy.

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