Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and an insulating piece. The shell comprises a first wall used for abutting against a heat exchange piece. The electrode assembly is accommodated in the shell, and the insulating piece is arranged on the surface of the electrode assembly. The insulating piece comprises a first insulating part and a second insulating part connected with each other. The thermal conductivity of the first insulating part is greater than that of the second insulating part. The first insulating part is arranged between the first wall and the electrode assembly. According to the application, the heat management performance of the battery can be effectively improved.

Description

Technical Field

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

[0002] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] In the development of battery technology, improving the heat exchange efficiency of individual battery cells is a continuous research direction. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can effectively improve the thermal management performance of the battery.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and an insulating member. The housing includes a first wall for contacting a heat exchanger. The electrode assembly is housed within the housing, and the insulating member is disposed on the surface of the electrode assembly. The insulating member includes a first insulating portion and a second insulating portion connected together. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion, and the first insulating portion is disposed between the first wall and the electrode assembly.

[0006] The above technical solution differentiates the thermal conductivity of the first and second insulating parts. On one hand, the first insulating part has a higher thermal conductivity, enabling the formation of an efficient heat conduction path between the electrode assembly and the first wall, thereby accelerating heat conduction between the heat exchanger and the battery cell and improving heat exchange efficiency. On the other hand, the second insulating part has a lower thermal conductivity, reducing heat transfer in unnecessary directions, thus mitigating the risk of thermal runaway caused by excessively rapid temperature rise in areas where no heat exchanger is installed. This effectively improves the battery's thermal management performance.

[0007] In some embodiments of the first aspect, the thermal conductivity of the first insulating part is 0.02 W / mK to 800 W / mK.

[0008] By setting the thermal conductivity of the first insulating part within the aforementioned range, the above technical solution can reduce the manufacturing cost of the battery cell to a certain extent while meeting the heat exchange efficiency requirements of the battery cell.

[0009] In some embodiments of the first aspect, the thermal conductivity of the first insulating portion is 0.05 W / mK to 400 W / mK. This achieves a balance between improving the heat exchange efficiency of the battery cell and reducing manufacturing costs.

[0010] In some embodiments of the first aspect, the first insulating portion includes a substrate and a thermally conductive material, wherein the strength of the substrate is greater than the strength of the thermally conductive material, and the thermal conductivity of the thermally conductive material is greater than the thermal conductivity of the substrate.

[0011] The above technical solution achieves an effective balance between thermal conductivity, structural stability, and manufacturing difficulty by setting the first insulating part as a composite structure including a substrate and a thermally conductive material. The substrate has high strength, which improves the structural stability and plasticity of the first insulating part, while the thermally conductive material has a high thermal conductivity, ensuring the thermal conductivity of the first insulating part. Furthermore, by adjusting the types and proportions of the substrate and the thermally conductive material, the first insulating part can be adapted to various application scenarios, improving the applicability of the battery cell.

[0012] In some embodiments of the first aspect, the thermally conductive material in the first insulating portion accounts for 3%-95% of the mass.

[0013] The above technical solution, by setting the thermally conductive material in the first insulating part within the above-mentioned range, can reduce the manufacturing difficulty of the battery cell to a certain extent while satisfying the heat exchange efficiency of the battery cell.

[0014] In some embodiments of the first aspect, the thermally conductive material in the first insulating portion accounts for 5%-90% of the total mass. This achieves a balance between improving the heat exchange efficiency of the battery cell and reducing manufacturing difficulty.

[0015] In some embodiments of the first aspect, the first wall and the electrode assembly are disposed along a first direction, and the second insulating portion is connected to the edge of the first insulating portion and disposed along a direction intersecting the first direction with the electrode assembly. The second insulating portion includes at least two thermally conductive regions, which are sequentially arranged adjacent to each other along the first direction. In the first direction and in a direction away from the first insulating portion, the thermal conductivity of the at least two thermally conductive regions decreases sequentially.

[0016] The second insulating part of the above-mentioned technical solution adopts a gradient thermal conductivity design along the first direction. The thermal conductivity of the thermally conductive area farther away from the first insulating part is smaller, and the thermal conductivity of the thermally conductive area closer to the first insulating part is larger. This gradient design allows for more precise control and transfer of heat, thereby effectively concentrating and guiding it to the first insulating part, further enhancing the directional heat transfer efficiency to the first insulating part. In addition, this gradient design can also achieve more stable thermal management in the overall structure, which helps to further improve the reliability of the battery cell.

[0017] In some embodiments of the first aspect, the second insulating portion includes a first portion and a second portion connected together. The first portion is disposed with the electrode assembly along a second direction and connected to the edge of the first insulating portion along the second direction. The second portion is disposed with the electrode assembly along a third direction and connected to the edge of the first insulating portion along the third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other. At least one of the first portion and the second portion includes at least two thermally conductive areas.

[0018] The above technical solution, by setting the second insulating part as a multi-directional covering design including the first part and the second part, facilitates the flexible selection of the setting position of the heat conduction zone according to actual needs, thereby improving the design flexibility of the battery cell.

[0019] In some embodiments of the first aspect, the area of ​​the first portion is larger than the area of ​​the second portion, and the first portion includes at least two heat-conducting regions.

[0020] The relatively large area of ​​the first part reduces the design difficulty of the heat conduction area, which in turn helps to reduce the overall fabrication difficulty of the battery cell.

[0021] In some embodiments of the first aspect, the difference in thermal conductivity between two adjacent heat-conducting regions is 0.01 W / mK to 20 W / mK.

[0022] The above technical solution, by setting the difference in thermal conductivity between two adjacent heat-conducting zones within the aforementioned range, can improve the reliability of battery cells while meeting the thermal management requirements of individual cells.

[0023] In some embodiments of the first aspect, the difference in thermal conductivity between two adjacent thermally conductive zones is 0.05 W / mK to 10 W / mK. This can further improve the balance between the thermal management performance and reliability of the battery cell.

[0024] In some embodiments of the first aspect, the thickness of the first insulating portion is 0.02 mm to 0.6 mm.

[0025] The above technical solution, by setting the thickness of the first insulating part within the above range, can reduce the occupation of the internal space of the battery cell to a certain extent while satisfying the reliability of the first insulating part, thereby helping to improve the energy density of the battery cell.

[0026] In some embodiments of the first aspect, the thickness of the first insulating portion is 0.05 mm to 0.3 mm. This can further improve the balance between the reliability and energy density of the battery cell.

[0027] In some embodiments of the first aspect, the first wall carries the electrode assembly, and the battery cell further includes a base plate disposed between the first insulating portion and the first wall.

[0028] The base plate of the above technical solution is used to elevate the electrode assembly, reduce the risk of damage to the electrode assembly caused by squeezing between the corner of the electrode assembly and the first wall, and improve the reliability of the battery cell.

[0029] In some embodiments of the first aspect, the thermal conductivity of the base plate is greater than that of the second insulating portion. This can further improve the heat conduction efficiency between the electrode assembly and the first wall.

[0030] In some embodiments of the first aspect, the thickness of the base plate is 0.05mm-6mm.

[0031] The above technical solution, by setting the thickness of the base plate within the aforementioned range, can reduce the occupancy of the internal space of the battery cell to a certain extent while ensuring the reliability of the base plate, thereby helping to improve the energy density of the battery cell.

[0032] In some embodiments of the first aspect, the thickness of the base plate is 0.1mm-3mm. This can further improve the balance between the reliability and energy density of the battery cells.

[0033] In some embodiments of the first aspect, the electrode assembly includes an electrode body and a tab, the tab extending from one end face of the electrode body, a first wall located on the side of the electrode body opposite to the tab, and a first insulating portion disposed between the first wall and the electrode body.

[0034] The above technical solution enables heat to be conducted away from the tabs, significantly reducing the impact of high temperature on the tabs and reducing problems such as increased resistance or battery performance degradation caused by overheating of the tabs, thereby improving the reliability of the battery cells.

[0035] In some embodiments of the first aspect, the electrode assembly includes an electrode body and a tab, the tab extending from one end face of the electrode body along a first direction, a first wall and the electrode assembly being disposed along a second direction, a first insulating portion being disposed between the first wall and the electrode body, and the first direction intersecting the second direction.

[0036] The above technical solution can provide a larger installation space for the first insulating part, which can not only reduce the installation difficulty of the first insulating part, but also further improve the thermal conductivity of the battery cell.

[0037] In some embodiments of the first aspect, the housing further includes a second wall disposed along a third direction with the electrode assembly, the first direction, the second direction, and the third direction being perpendicular to each other. The first wall is connected to the second wall, the area of ​​the first wall is larger than the area of ​​the second wall, and at least a portion of the second insulating portion is disposed between the electrode body and the second wall.

[0038] The first wall has a relatively large area, which can provide a larger thermal conductivity interface to further improve the thermal conductivity of the battery cell.

[0039] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0040] In some embodiments of the second aspect, the battery device further includes a heat exchanger attached to the first wall.

[0041] Thirdly, this application provides an electrical device that includes a battery cell provided in any embodiment of the first aspect or a battery device provided in any embodiment of the second aspect, wherein the battery cell or battery device is used to store or provide electrical energy.

[0042] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0043] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0044] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0045] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0046] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0047] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application;

[0048] Figure 5 This is a schematic cross-sectional view of a battery cell provided in some embodiments of this application;

[0049] Figure 6 for Figure 5 A magnified schematic diagram of the local structure at point G;

[0050] Figure 7 A three-dimensional structural schematic diagram of an insulating component for a battery cell provided in some embodiments of this application;

[0051] Figure 8 A cross-sectional structural schematic diagram of an insulating component for a battery cell provided in some embodiments of this application;

[0052] Figure 9 This is a schematic cross-sectional view of another battery cell provided in some embodiments of this application;

[0053] Figure 10 for Figure 9 A magnified schematic diagram of the structure at point H.

[0054] The attached figures are labeled as follows:

[0055] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 6. Battery module; 7. Battery cell;

[0056] 10. Outer shell; 11. First wall; 12. Second wall;

[0057] 20. Electrode assembly; 21. Electrode body; 22. Tab;

[0058] 30. Insulating component; 31. First insulating part; 32. Second insulating part; 321. First portion; 322. Second portion; 33. Thermally conductive area; 33a. First thermally conductive area; 33b. Second thermally conductive area; 33c. Third thermally conductive area;

[0059] 40. Base plate;

[0060] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0061] 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 and completely 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.

[0062] 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 specification 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 specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In this application, "multiple" means two or more (including two).

[0068] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0069] With the development of the new energy vehicle industry, the performance requirements for power batteries are becoming increasingly stringent. Faster charging speeds and higher operating power pose greater challenges to battery heat conduction.

[0070] In related technologies, heat conduction in power batteries mainly relies on water-cooled heat exchangers. However, the structural design of these heat exchangers is limited by factors such as vehicle model, space, and cost, making a uniform approach impossible. Therefore, it is necessary to improve the thermal conductivity of individual battery cells in the corresponding directions, based on the location of different heat exchangers.

[0071] Based on the above considerations, this application designs a battery cell, which includes a casing, an electrode assembly, and an insulating component. The casing includes a first wall for contacting a heat exchange component. The electrode assembly is housed within the casing, and the insulating component is disposed on the surface of the electrode assembly. The insulating component includes a first insulating portion and a second insulating portion connected together. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion, and the first insulating portion is disposed between the first wall and the electrode assembly.

[0072] The above technical solution differentiates the thermal conductivity of the first and second insulating parts. On one hand, the first insulating part has a higher thermal conductivity, enabling the formation of an efficient heat conduction path between the electrode assembly and the first wall, thereby accelerating heat conduction between the heat exchanger and the battery cell and improving heat exchange efficiency. On the other hand, the second insulating part has a lower thermal conductivity, reducing heat transfer in unnecessary directions, thus mitigating the risk of thermal runaway caused by excessively rapid temperature rise in areas where no heat exchanger is installed. This effectively improves the battery's thermal management performance.

[0073] 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.

[0074] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0075] Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0076] like Figure 1As 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.

[0077] 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.

[0078] 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.

[0079] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0080] In some embodiments, the battery device 2 may include one or more battery cell assemblies for providing voltage and capacity.

[0081] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown), multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0082] A battery cell can be a rechargeable 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.

[0083] As an example, a single battery cell 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.

[0084] As an example, a battery cell can be 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.

[0085] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module 6, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module 6 can be formed by bundling multiple battery cells together with cable ties.

[0086] 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 6, which can be housed within the housing by securing the battery module 6 to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0087] In some embodiments, the housing 5 is used to house individual battery cells, and the housing 5 can have various structures.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] In some embodiments, the battery device 2 may be an energy storage device.

[0092] 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.

[0093] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0094] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0095] In some embodiments, such as Figure 3 As shown, there are multiple battery cells 7, which are first connected in series, parallel, or a combination of both to form a battery module 6. These battery modules 6 are then connected in series, parallel, or a combination of both to form a whole, which is housed within the casing.

[0096] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6. There can be one or more busbars, each used to electrically connect at least two battery cells 7.

[0097] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0098] In some embodiments, the outer casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0099] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0100] In some embodiments, the casing of the battery cell is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0101] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being connected to the housing and covering the opening;

[0102] The housing is a component used to fit the end cap to form the internal cavity of the battery cell. The formed internal cavity can be used to house the electrode assembly, electrolyte, and other components.

[0103] The housing and end cap can be separate components. For example, an opening can be provided on the housing, and the end cap can be used to close the opening to form an internal cavity for the battery cell.

[0104] The housing can come in various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, and aluminum alloy.

[0105] The shape of the end cap can be adapted to the shape of the housing to fit the housing. The material of the end cap can be the same as or different from that of the housing. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell to have higher strength and improve reliability.

[0106] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0107] The housing may be open at one end or at both ends. In some examples, the housing may be a structure with an opening on one side, with one end cap fitting over the housing. In other examples, the housing may be a structure with openings on both sides, with two end caps fitting over the two openings of the housing, respectively.

[0108] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0109] In some embodiments, the electrode assembly includes a positive electrode and a negative electrode, wherein the positive electrode and the negative electrode have opposite polarities.

[0110] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

[0111] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0112] 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.).

[0113] As an example, the positive electrode film 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 positive electrode active materials for batteries 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 0.3O2 (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 0.05 At 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.

[0114] In some embodiments, the negative electrode may include a negative current collector.

[0115] 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.).

[0116] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0117] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0118] As an example, the negative electrode film 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 in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0119] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0120] In some embodiments, the electrode assembly further includes a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0121] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0122] 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.

[0123] 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.

[0124] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0125] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0126] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0127] In some implementations, the electrode assembly is a stacked structure.

[0128] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0129] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0130] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0131] In some embodiments, the positive current collector may include a positive tab, and the negative current collector may include a negative tab. The positive and negative tabs can be used to transmit current. As an example, at least a portion of the positive tab is not coated with a positive film layer, and at least a portion of the negative tab is not coated with a negative film layer.

[0132] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0133] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0134] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of a positive current collector covered by the positive electrode film, a negative electrode film, and a portion of a negative current collector covered by the negative electrode film.

[0135] The positive and negative electrodes can be drawn from the same end of the electrode body, or they can be drawn from opposite ends of the electrode body.

[0136] In some embodiments, a battery cell includes a positive electrode lead and a negative electrode lead, wherein the positive electrode lead is electrically connected to a positive electrode plate and the negative electrode lead is electrically connected to a negative electrode plate.

[0137] The positive and negative leads are used to connect to the external circuit to enable charging or discharging of the battery cells.

[0138] In some embodiments, the positive lead-out portion includes a positive terminal. At least a portion of the positive terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0139] As an example, the positive terminal may be a separately molded component that is mounted on the housing. Alternatively, the positive terminal may also be part of the housing.

[0140] In some examples, the positive terminal is directly connected to the positive plate; in other examples, the positive terminal and the positive plate are indirectly connected through other conductive structures, such as a positive adapter plate.

[0141] In some embodiments, the positive terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0142] In some embodiments, the negative lead-out portion includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell to facilitate connection with a busbar.

[0143] As an example, the negative terminal can be a separately molded component that is mounted on the housing. Alternatively, the negative terminal can also be part of the housing.

[0144] In some examples, the negative terminal is directly connected to the negative electrode plate; in other examples, the negative lead-out section also includes other conductive structures connecting the negative terminal and the negative electrode plate, such as a negative electrode adapter plate.

[0145] In some embodiments, the negative terminal is attached to the end cap by welding, riveting, snap-fitting, or other means.

[0146] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in some embodiments of this application. Figure 5 This is a schematic cross-sectional view of a single battery cell provided in some embodiments of this application. Figure 6 for Figure 5 A magnified schematic diagram of the local structure at point G.

[0147] Continue to refer to Figures 4 to 6 This application provides a battery cell 7, which includes a housing 10, an electrode assembly 20, and an insulating member 30. The housing 10 includes a first wall 11 for contacting a heat exchanger. The electrode assembly 20 is housed within the housing 10, and the insulating member 30 is disposed on the surface of the electrode assembly 20. The insulating member 30 includes a first insulating portion 31 and a second insulating portion 32 connected together. The thermal conductivity of the first insulating portion 31 is greater than that of the second insulating portion 32, and the first insulating portion 31 is disposed between the first wall 11 and the electrode assembly 20.

[0148] As an example, the first wall 11 can be an end cap or a wall of the housing.

[0149] The first wall 11 is used to contact the heat exchanger; in other words, the first wall 11 is the wall of the outer casing 10 closest to the heat exchanger. The location of the first wall 11 is the area where heat transfer between the battery cell 7 and the heat exchanger is fastest.

[0150] The heat exchanger is thermally connected (e.g., bonded) to at least a portion of the battery cell 7, and the heat exchange medium flows within the heat exchanger and exchanges heat with the battery cell 7 through the heat exchanger. When the temperature of the battery cell 7 is too high, the heat exchanger can cool the battery cell 7; when the temperature of the battery cell 7 is too low, the heat exchanger can keep the battery cell 7 warm, thereby improving the battery's lifespan.

[0151] For example, when the heat exchanger cools the battery cell 7, the heat generated by the battery cell 7 is mainly conducted to the heat exchanger through the first wall 11; when the heat exchanger heats the battery cell 7, the heat of the heat exchanger is mainly conducted to the battery cell 7 through the first wall 11.

[0152] An insulating element 30 is disposed on the surface of the electrode assembly 20, and the insulating element 30 is used to insulate the electrode assembly 20 from the housing 10.

[0153] As an example, the housing 10 includes a housing and an end cap, the electrode assembly 20 includes an electrode body 21 and an electrode tab 22, the electrode tab 22 extends from one end face of the electrode body 21 toward the end cap, and an insulating member 30 is disposed on the surface of the electrode body 21 to provide an insulating gap between the electrode body 21 and the housing.

[0154] As an example, the insulating element 30 can be attached to the surface of the electrode assembly 20. Attachment means adhering, coating or spraying. Installing and fixing the insulating element 30 by attachment helps to reduce structural complexity and cost.

[0155] Thermal conductivity is a physical parameter that measures the ability to conduct heat. The higher the thermal conductivity, the stronger the ability to conduct heat; the lower the thermal conductivity, the weaker the ability to conduct heat. The first insulating part 31 has a greater ability to conduct heat than the second insulating part 32.

[0156] For example, the first insulating part 31 is disposed between the first wall 11 and the electrode assembly 20, and the second insulating part 32 is disposed between the other walls of the housing 10 (excluding the first wall 11) and the electrode assembly 20. Because the first insulating part 31 has a higher thermal conductivity, the heat conduction efficiency between the electrode assembly 20 and the first insulating part 31 is greater than the heat conduction efficiency between the electrode assembly 20 and the second insulating part 32.

[0157] In other words, when the heat exchanger cools the battery cell 7, more of the heat generated by the electrode assembly 20 can be conducted to the first wall 11 through the first insulation portion 31, and then to the heat exchanger through the first wall 11. Alternatively, when the heat exchanger heats the battery cell 7, more of the heat from the heat exchanger can be quickly conducted to the electrode assembly 20 through the first wall 11 and the first insulation portion 31.

[0158] The first insulating portion 31 may be attached between the first wall 11 and the electrode assembly 20. As an example, the first insulating portion 31 may be attached to the electrode assembly 20, the first insulating portion 31 may be attached to the first wall 11, or the first insulating portion 31 may be attached to both the electrode assembly 20 and the first wall 11.

[0159] Optionally, the insulating element 30 may include, but is not limited to, one or more of polypropylene, polyphenylene sulfide, polyethylene, polyamide, polyvinyl chloride, boron nitride, gallium nitride, aluminum nitride, silicon carbide, aluminum oxide, beryllium oxide, silicon dioxide, and magnesium oxide.

[0160] The above technical solution differentiates the thermal conductivity of the first insulating part 31 and the second insulating part 32. On the one hand, the first insulating part 31 has a high thermal conductivity, which can form an efficient heat conduction path between the electrode assembly 20 and the first wall 11, thereby accelerating the heat conduction between the heat exchanger and the battery cell 7 and improving heat exchange efficiency. On the other hand, the second insulating part 32 has a low thermal conductivity, which can reduce heat transfer in unnecessary directions, thereby reducing the risk of thermal runaway caused by the battery overheating too quickly in areas where no heat exchanger is provided. In this way, the thermal management performance of the battery can be effectively improved.

[0161] For example, the thermal conductivity of the first insulating portion 31 and the second insulating portion 32 can be measured using either a steady-state method or a transient method. The steady-state method involves applying a constant temperature gradient across the two ends of a material sample and measuring the heat flux density and temperature difference under steady-state conditions to calculate the thermal conductivity; examples include the heat flux method and the heated plate method. The transient method measures the thermal conductivity under unsteady-state conditions; examples include the hot wire method, the laser scintillation method, and the transient planar heat source method.

[0162] In some embodiments, the thermal conductivity of the first insulating portion 31 is 0.02 W / mK to 800 W / mK.

[0163] As an example, the thermal conductivity of the first insulating part 31 may be, but is not limited to, 0.02W / mK, 1W / mK, 10W / mK, 50W / mK, 100W / mK, 300W / mK, 500W / mK, 600W / mK, 800W / mK, etc.

[0164] It is understandable that the higher the thermal conductivity of a material, the better its thermal conductivity, but this will also increase its manufacturing cost to some extent.

[0165] By setting the thermal conductivity of the first insulating part 31 within the above-mentioned range, the above-mentioned technical solution can reduce the manufacturing cost of the battery cell 7 to a certain extent while satisfying the heat exchange efficiency of the battery cell 7.

[0166] In some embodiments, the thermal conductivity of the first insulating portion 31 is 0.05 W / mK to 400 W / mK. This achieves a balance between improving the heat exchange efficiency of the battery cell 7 and reducing manufacturing costs.

[0167] As an example, the thermal conductivity of the first insulating part 31 may be, but is not limited to, 0.05W / mK, 5W / mK, 20W / mK, 60W / mK, 120W / mK, 200W / mK, 250W / mK, 300W / mK, 400W / mK, etc.

[0168] In some embodiments, the first insulating portion 31 includes a substrate and a thermally conductive material, wherein the strength of the substrate is greater than the strength of the thermally conductive material, and the thermal conductivity of the thermally conductive material is greater than the thermal conductivity of the substrate.

[0169] Strength refers to the ability of a material or structure to resist fracture, excessive deformation, and failure. Higher strength indicates a stronger ability of the material or structure to resist fracture, excessive deformation, and failure; lower strength indicates a weaker ability. In the embodiments of this application, strength refers to at least one of tensile strength, compressive strength, flexural strength, yield strength, and shear strength.

[0170] For example, the strength of substrates and thermally conductive materials can be measured using methods such as tensile testing, bending testing, compression testing, impact testing, or shear testing. As an example, in impact testing, the energy absorption and toughness are measured by impacting the specimen with a pendulum or falling hammer; common examples include the Charpy impact test and the Arachne impact test. As another example, in tensile testing, the tensile strength of the material is measured by applying a tensile force. Specific procedures for other testing methods can be found in existing technical literature and will not be elaborated here.

[0171] Optionally, the substrate may include, but is not limited to, one or more of polypropylene, polyphenylene sulfide, polyethylene, polyamide, and polyvinyl chloride.

[0172] Optionally, the thermally conductive material may include, but is not limited to, one or more of boron nitride, gallium nitride, aluminum nitride, silicon carbide, aluminum oxide, beryllium oxide, silicon dioxide, and magnesium oxide.

[0173] The above technical solution achieves an effective balance between thermal conductivity, structural stability, and manufacturing difficulty by configuring the first insulating part 31 as a composite structure including a substrate and a thermally conductive material. The substrate has high strength, which improves the structural stability and plasticity of the first insulating part 31, while the thermally conductive material has a high thermal conductivity, ensuring the thermal conductivity of the first insulating part 31. Furthermore, by adjusting the type and ratio of the substrate and the thermally conductive material, the first insulating part 31 can be adapted to various application scenarios, improving the applicability of the battery cell 7.

[0174] In some embodiments, the thermally conductive material in the first insulating portion 31 accounts for 3%-95% of the mass.

[0175] As an example, the thermal conductivity of the first insulating part 31 may be, but is not limited to, 3%, 10%, 20%, 50%, 70%, 90%, 95%, etc.

[0176] It is understandable that the greater the mass ratio of the thermally conductive material in the first insulating part 31, the better the thermal conductivity of the first insulating part 31 will be. At the same time, it will also make the plasticity of the first insulating part 31 worse and increase the difficulty of its preparation.

[0177] The above technical solution, by setting the thermally conductive material in the first insulating part 31 within the above-mentioned range, can reduce the manufacturing difficulty of the battery cell 7 to a certain extent while satisfying the heat exchange efficiency of the battery cell 7.

[0178] In some embodiments, the thermally conductive material in the first insulating portion 31 accounts for 5%-90% of the mass. This achieves a balance between improving the heat exchange efficiency of the battery cell 7 and reducing manufacturing difficulty.

[0179] As an example, the thermal conductivity of the first insulating part 31 may be, but is not limited to, 5%, 15%, 25%, 40%, 75%, 85%, 90%, etc.

[0180] Figure 7 This is a three-dimensional structural schematic diagram of an insulating component for a battery cell provided in some embodiments of this application. Figure 8 This is a cross-sectional structural diagram of an insulating component for a battery cell provided in some embodiments of this application.

[0181] Continue to refer to Figures 7 to 8 In some embodiments, the first wall 11 and the electrode assembly 20 are disposed along a first direction X, and the second insulating portion 32 is connected to the edge of the first insulating portion 31 and disposed with the electrode assembly 20 in a direction intersecting the first direction X. The second insulating portion 32 includes at least two heat-conducting regions 33, which are sequentially arranged adjacent to each other along the first direction X. In the first direction X and in a direction away from the first insulating portion 31, the thermal conductivity of the at least two heat-conducting regions 33 decreases sequentially.

[0182] The number of heat-conducting areas 33 is greater than or equal to two, for example, two, three, four or more. The specific number of heat-conducting areas 33 can be selected according to the actual application environment, for example, it can be selected according to the dimension of the housing 10 along the first direction X.

[0183] For example, there are three heat-conducting regions 33. In the first direction X and in a direction away from the first insulating part 31, the three heat-conducting regions 33 are respectively configured as a first heat-conducting region 33a, a second heat-conducting region 33b, and a third heat-conducting region 33c. The first heat-conducting region 33a is closest to the second insulating part 32, and the third heat-conducting region 33c is farthest from the second insulating part 32. The second heat-conducting region 33b is connected between the first heat-conducting region 33a and the third heat-conducting region 33c. The thermal conductivity of the first heat-conducting region 33a is greater than that of the second heat-conducting region 33b, and the thermal conductivity of the second heat-conducting region 33b is greater than that of the third heat-conducting region 33c.

[0184] In the above-described technical solution, the second insulating portion 32 adopts a gradient thermal conductivity design along the first direction X. The thermal conductivity of the thermally conductive area 33 is lower the farther away from the first insulating portion 31, and higher the thermal conductivity of the thermally conductive area 33 is higher the closer to the first insulating portion 31. This gradient design allows for more precise control and transfer of heat, effectively concentrating and guiding it to the first insulating portion 31, further enhancing the directional heat transfer efficiency to the first insulating portion 31. Furthermore, this gradient design enables more stable thermal management within the overall structure, contributing to further improving the reliability of the battery cell 7.

[0185] In some embodiments, the second insulating portion 32 includes a first portion 321 and a second portion 322 connected together. The first portion 321 is disposed with the electrode assembly 20 along a second direction Y and connected to the edge of the first insulating portion 31 along the second direction Y. The second portion 322 is disposed with the electrode assembly 20 along a third direction Z and connected to the edge of the first insulating portion 31 along the third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. At least one of the first portion 321 and the second portion 322 includes at least two thermally conductive regions 33.

[0186] For example, the outer shell 10 is a square outer shell 10, the electrode assembly 20 is a square electrode assembly 20, and the first insulating part 31, the first part 321 and the second part 322 are respectively disposed on three adjacent surfaces of the electrode assembly 20.

[0187] The first part 321 may include at least two heat-conducting areas 33, while the second part 322 may not have heat-conducting areas 33; the second part 322 may include at least two heat-conducting areas 33, while the first part 321 may not have heat-conducting areas 33; or the first part 321 may include at least two heat-conducting areas 33, and the second part 322 may also include at least two heat-conducting areas 33.

[0188] In some examples, there are two first parts 321 and two second parts 322. The two first parts 321 are arranged opposite each other along the second direction Y, and the two second parts 322 are arranged opposite each other along the third direction Z. The first insulating part 31, the two first parts 321 and the two second parts 322 are connected to form a square cylindrical structure.

[0189] The above technical solution, by setting the second insulating part 32 to a multi-directional covering design including the first part 321 and the second part 322, facilitates the flexible selection of the setting position of the heat conduction area 33 according to actual needs, thereby improving the design flexibility of the battery cell 7.

[0190] In some embodiments, the area of ​​the first portion 321 is larger than the area of ​​the second portion 322, and the first portion 321 includes at least two heat-conducting regions 33.

[0191] For example, the area of ​​the first part 321 can be understood as the projected area of ​​the first part 321 along the second direction Y, and the area of ​​the second part 322 can be understood as the projected area of ​​the second part 322 along the third direction Z. That is, the projected area of ​​the first part 321 along the second direction Y is greater than the projected area of ​​the second part 322 along the third direction Z.

[0192] The relatively large area of ​​the first part 321 can reduce the design difficulty of the heat conduction area 33, thereby helping to reduce the overall fabrication difficulty of the battery cell 7.

[0193] In some embodiments, the difference in thermal conductivity between two adjacent heat-conducting regions 33 is 0.01 W / mK to 20 W / mK.

[0194] For example, the difference in thermal conductivity between two adjacent heat-conducting regions 33 can be understood as the gradient value of the gradient thermal conduction design of the second insulating part 32 along the first direction X, that is, the larger thermal conductivity of the two adjacent heat-conducting regions 33 minus the smaller thermal conductivity.

[0195] As an example, the difference in thermal conductivity between two adjacent heat-conducting zones 33 can be, but is not limited to, 0.01 W / mK, 1 W / mK, 2 W / mK, 5 W / mK, 10 W / mK, 12 W / mK, 14 W / mK, 18 W / mK, 20 W / mK, etc.

[0196] It is understandable that the greater the difference in thermal conductivity between two adjacent heat-conducting regions 33, the more obvious a thermal conduction barrier will be formed between the heat-conducting region 33 with high thermal conductivity and the heat-conducting region 33 with low thermal conductivity, causing heat to concentrate and be transferred along the heat-conducting region 33 with high thermal conductivity, thereby achieving better directional control of heat. However, if the difference in thermal conductivity between two adjacent heat-conducting regions 33 is too large, large interfacial thermal stress is easily generated between the two adjacent heat-conducting regions 33, making the second insulating part 32 prone to cracking.

[0197] The smaller the difference in thermal conductivity between two adjacent heat-conducting regions 33, the smaller the interfacial thermal stress between the two adjacent heat-conducting regions 33. However, if the difference in thermal conductivity between two adjacent heat-conducting regions 33 is too small, the thermal conductivity of each heat-conducting region 33 will be relatively similar, and the heat will diffuse relatively uniformly in all directions, making it difficult to concentrate and conduct to the first insulating part 31, resulting in poor directional control of heat.

[0198] The above technical solution, by setting the difference in thermal conductivity between two adjacent heat-conducting zones 33 within the above range, can improve the reliability of the battery cell 7 while meeting the thermal management requirements of the battery cell 7.

[0199] In some embodiments, the difference in thermal conductivity between two adjacent thermally conductive regions 33 is 0.05 W / mK to 10 W / mK. This can further improve the balance between the thermal management performance and reliability of the battery cell 7.

[0200] As an example, the difference in thermal conductivity between two adjacent heat-conducting regions 33 can be, but is not limited to, 0.05 W / mK, 0.5 W / mK, 1.5 W / mK, 3 W / mK, 4 W / mK, 5 W / mK, 6 W / mK, 7 W / mK, 8 W / mK, 9 W / mK, 10 W / mK, etc.

[0201] In some embodiments, the thickness of the first insulating portion 31 is 0.02 mm to 0.6 mm.

[0202] For example, when the first wall 11 and the electrode assembly 20 are arranged along the first direction X, the thickness of the first insulating portion 31 can be understood as the size of the first insulating portion 31 along the first direction X.

[0203] As an example, the thickness of the first insulating part 31 may be, but is not limited to, 0.02mm, 0.1mm, 0.15mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc.

[0204] It is understandable that the greater the thickness of the first insulating portion 31, the better its reliability, but also the greater its occupancy of the internal space of the battery cell 7. Conversely, the smaller the thickness of the first insulating portion 31, the worse its reliability, but also the smaller its occupancy of the internal space of the battery cell 7.

[0205] By setting the thickness of the first insulating part 31 within the above-mentioned range, the above-mentioned technical solution can reduce the occupation of the internal space of the battery cell 7 to a certain extent while satisfying the reliability of the first insulating part 31, thereby helping to improve the energy density of the battery cell 7.

[0206] In some embodiments, the thickness of the first insulating portion 31 is 0.05mm-0.3mm. This can further improve the balance between the reliability and energy density of the battery cell 7.

[0207] As an example, the thickness of the first insulating part 31 may be, but is not limited to, 0.05mm, 0.15mm, 0.18mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, etc.

[0208] In some embodiments, the first wall 11 supports the electrode assembly 20, and the battery cell 7 further includes a base plate 40 disposed between the first insulating portion 31 and the first wall 11.

[0209] The first wall 11 bearing the electrode assembly 20 means that the first wall 11 is used to provide support for the electrode assembly 20, wherein the support provided by the first wall 11 to the electrode assembly 20 is relative to the gravity acting on the electrode assembly 20.

[0210] As an example, the base plate 40 is connected to the first wall 11.

[0211] The base plate 40 can be detachably connected to the first wall 11, or it can be integrally mounted on the first wall 11. The base plate 40 can be directly connected to the first wall 11, or it can be constrained to the first wall 11 by other components.

[0212] Optionally, the base plate 40 may include, but is not limited to, one or more of the following: polypropylene, polyphenylene sulfide, polyethylene, polyamide, polyvinyl chloride, boron nitride, gallium nitride, aluminum nitride, silicon carbide, aluminum oxide, beryllium oxide, silicon dioxide, and magnesium oxide.

[0213] As an example, the base plate 40 and the insulating element 30 can be made of the same material to simplify the manufacturing process and reduce costs.

[0214] The base plate 40 of the above technical solution is used to elevate the electrode assembly 20, reduce the risk of damage to the electrode assembly 20 caused by squeezing between the corner of the electrode assembly 20 and the first wall 11, and improve the reliability of the battery cell 7.

[0215] In some embodiments, the thermal conductivity of the base plate 40 is greater than that of the second insulating portion 32, which can further improve the heat conduction efficiency between the electrode assembly 20 and the first wall 11.

[0216] In some embodiments, the thickness of the base plate 40 is 0.05mm-6mm.

[0217] For example, when the first wall 11 and the electrode assembly 20 are arranged along the first direction X, the thickness of the base plate 40 can be understood as the size of the base plate 40 along the first direction X.

[0218] As an example, the thickness of the first insulating part 31 may be, but is not limited to, 0.05mm, 0.5mm, 0.8mm, 1mm, 2mm, 4mm, 5mm, 6mm, etc.

[0219] Understandably, the greater the thickness of the base plate 40, the better its reliability, but also the greater the space it occupies inside the battery cell 7. Conversely, the smaller the thickness of the base plate 40, the worse its reliability, but also the smaller the space it occupies inside the battery cell 7.

[0220] By setting the thickness of the base plate 40 within the aforementioned range, the above-mentioned technical solution can reduce the occupancy of the internal space of the battery cell 7 to a certain extent while ensuring the reliability of the base plate 40, thereby helping to improve the energy density of the battery cell 7.

[0221] In some embodiments, the thickness of the base plate 40 is 0.1mm-3mm. This can further improve the balance between the reliability and energy density of the battery cell 7.

[0222] As an example, the thickness of the first insulating part 31 may be, but is not limited to, 0.1mm, 0.15mm, 0.8mm, 1mm, 2mm, 2.5mm, 3mm, etc.

[0223] In some embodiments, the electrode assembly 20 includes an electrode body 21 and a tab 22. The tab 22 extends from one end face of the electrode body 21. A first wall 11 is located on the side of the electrode body 21 facing away from the tab 22. A first insulating portion 31 is disposed between the first wall 11 and the electrode body 21.

[0224] The above technical solution enables heat to be conducted away from the tab 22, which significantly reduces the impact of high temperature on the tab 22 and reduces problems such as increased resistance or battery performance degradation caused by overheating of the tab 22, thereby improving the reliability of the battery cell 7.

[0225] Figure 9 This is a schematic cross-sectional view of another battery cell provided in some embodiments of this application. Figure 10 for Figure 9 A magnified schematic diagram of the structure at point H.

[0226] Continue to refer to Figures 9 to 10 In some embodiments, the electrode assembly 20 includes an electrode body 21 and a tab 22. The tab 22 extends from one end face of the electrode body 21 along the first direction X. The first wall 11 and the electrode assembly 20 are disposed along the second direction Y. The first insulating part 31 is disposed between the first wall 11 and the electrode body 21. The first direction X intersects the second direction Y.

[0227] The above technical solution can provide a larger installation space for the first insulating part 31, which can not only reduce the installation difficulty of the first insulating part 31, but also further improve the thermal conductivity of the battery cell 7.

[0228] In some embodiments, the housing 10 further includes a second wall 12, which is disposed with the electrode assembly 20 along a third direction Z, wherein the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. A first wall 11 is connected to the second wall 12, and the area of ​​the first wall 11 is larger than the area of ​​the second wall 12. At least a portion of the second insulating portion 32 is disposed between the electrode body 21 and the second wall 12.

[0229] For example, the area of ​​the first wall 11 can be understood as the projected area of ​​the first wall 11 along the second direction Y, and the area of ​​the second wall 12 can be understood as the projected area of ​​the second wall 12 along the third direction Z. That is, the projected area of ​​the first wall 11 along the second direction Y is greater than the projected area of ​​the second wall 12 along the third direction Z.

[0230] The second insulating part 32 may be partly disposed between the electrode body 21 and the second wall 12, or the second insulating part 32 may be entirely disposed between the electrode body 21 and the second wall 12.

[0231] The first wall 11 has a relatively large area, which can provide a larger thermal conductivity interface to further improve the thermal conductivity of the battery cell 7.

[0232] According to some embodiments of this application, this application also provides a battery device including a battery cell 7 of any of the above schemes.

[0233] In some embodiments, the battery device further includes a heat exchanger that is attached to the first wall 11.

[0234] Exemplarily, a heat exchanger may be thermally connected (e.g., attached) to at least a portion of the battery cell 7, and a heat exchange medium flows within the heat exchanger and exchanges heat with the battery cell 7 through the heat exchanger. When the temperature of the battery cell 7 is too high, the heat exchanger can cool the battery cell 7; when the temperature of the battery cell 7 is too low, the heat exchanger can keep the battery cell 7 warm, thereby improving the battery's lifespan.

[0235] As an example, the heat exchanger has channels inside to accommodate the heat exchange medium. The sidewalls of the heat exchanger refer to the portions that enclose these channels.

[0236] The channels inside the heat exchanger can extend in a straight line or along a curve, depending on the actual application environment.

[0237] In some examples, the heat exchanger may be located between two adjacent battery cells 7.

[0238] In some examples, the battery cell 7 may be disposed between two adjacent heat exchangers, such that each battery cell 7 is in contact with the two heat exchangers on both sides respectively.

[0239] In some examples, the heat exchanger contacts the sidewall with the largest area of ​​the battery cell 7 to improve the battery's heat exchange efficiency.

[0240] In some examples, multiple heat exchangers can be connected by connecting pipes to achieve connection between the heat exchangers and circulation of the heat exchange medium.

[0241] Optionally, the heat exchange medium can be a liquid or a gas, wherein the liquid can be, but is not limited to, water, hot oil, ethylene glycol and alcohol; and the gas can be, but is not limited to, air, nitrogen or hydrogen.

[0242] Optionally, the heat exchanger may be, but is not limited to, made of metallic or non-metallic materials. For example, metallic materials may be copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, or stainless steel, while non-metallic materials may be ceramics, polyethylene, polypropylene, polyvinyl chloride, polyimide, or polyamide, etc.

[0243] According to some embodiments of this application, this application also provides an electrical device, including a battery cell 7 or a battery device of any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0244] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. All technical features and optional technical features of this application can be combined to form new technical solutions.

[0245] To better understand the battery cell 7 provided in the embodiments of this application, based on the same inventive concept, embodiments of the battery cell 7 in practical applications are provided here for illustration.

[0246] This application provides a battery cell 7, which includes a housing 10, an electrode assembly 20, an insulating member 30, and a base plate 40. The housing 10 includes a first wall 11 for contacting a heat exchanger. The electrode assembly 20 is housed within the housing 10 and includes an electrode body 21 and tabs 22. The tabs 22 extend from one end face of the electrode body 21 along a first direction X. The first wall 11 and the electrode assembly 20 are arranged along the first direction X. The insulating member 30 is disposed on the surface of the electrode body 21 and includes a first insulating portion 31 and a second insulating portion 32. The thermal conductivity of the first insulating portion 31 is greater than that of the second insulating portion 32. The first insulating portion 31 is disposed between the first wall 11 and the electrode body 21, and the thermal conductivity of the first insulating portion 31 is 0.05 W / mK-400 W / mK. The first insulating part 31 includes a substrate and a thermally conductive material. The strength of the substrate is greater than that of the thermally conductive material, and the thermal conductivity of the thermally conductive material is greater than that of the substrate. The mass percentage of the thermally conductive material in the first insulating part 31 is 5%-90%.

[0247] The second insulating portion 32 includes two first portions 321 and two second portions 322. The two first portions 321 are arranged opposite each other along the second direction Y and are respectively located on both sides of the electrode body 21 along the second direction Y, and the two first portions 321 are respectively connected to the two side edges of the first insulating portion 31 along the second direction Y. The two second portions 322 are arranged opposite each other along the third direction Z and are respectively located on both sides of the electrode body 21 along the third direction Z, and the two second portions 322 are respectively connected to the two side edges of the first insulating portion 31 along the third direction Z. At least one of the two first portions 321 and the two second portions 322 includes at least two heat-conducting regions 33. The at least two heat-conducting regions 33 are arranged sequentially adjacent to each other along the first direction X. In the first direction X and in the direction away from the first insulating portion 31, the thermal conductivity of the at least two heat-conducting regions 33 decreases sequentially. The first direction X, the second direction Y, and the third direction Z intersect each other.

[0248] The bottom plate 40 is disposed between the first insulating part 31 and the first wall 11, and the thermal conductivity of the bottom plate 40 is greater than that of the second insulating part 32.

[0249] The above technical solution differentiates the thermal conductivity of the first insulating part 31 and the second insulating part 32. On the one hand, the first insulating part 31 has a high thermal conductivity, which can form an efficient heat conduction path between the electrode assembly 20 and the first wall 11, thereby accelerating the heat conduction between the heat exchanger and the battery cell 7 and improving heat exchange efficiency. On the other hand, the second insulating part 32 has a low thermal conductivity, which can reduce heat transfer in unnecessary directions, thereby reducing the risk of thermal runaway caused by the battery overheating too quickly in areas where no heat exchanger is provided. In this way, the thermal management performance of the battery can be effectively improved.

[0250] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0251] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not 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 modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The housing includes a first wall for contacting the heat exchange element; Electrode assembly, housed within the housing; An insulating element is disposed on the surface of the electrode assembly. The insulating element includes a first insulating portion and a second insulating portion connected together. The thermal conductivity of the first insulating portion is greater than that of the second insulating portion. The first insulating portion is disposed between the first wall and the electrode assembly.

2. The battery cell according to claim 1, characterized in that, The thermal conductivity of the first insulating part is 0.02W / mK-800W / mK.

3. The battery cell according to claim 2, characterized in that, The thermal conductivity of the first insulating part is 0.05 W / mK-400 W / mK.

4. The battery cell according to claim 1, characterized in that, The first insulating part includes a substrate and a thermally conductive material, wherein the strength of the substrate is greater than the strength of the thermally conductive material, and the thermal conductivity of the thermally conductive material is greater than the thermal conductivity of the substrate.

5. The battery cell according to claim 4, characterized in that, The thermally conductive material in the first insulating part accounts for 3%-95% of the total mass.

6. The battery cell according to claim 5, characterized in that, The thermally conductive material in the first insulating part accounts for 5%-90% of the total mass.

7. The battery cell according to claim 1, characterized in that, The first wall and the electrode assembly are disposed along a first direction, and the second insulating portion is connected to the edge of the first insulating portion and disposed along a direction intersecting the first direction with the electrode assembly; The second insulating portion includes at least two heat-conducting areas, and the at least two heat-conducting areas are arranged adjacent to each other along the first direction; In the first direction and in the direction away from the first insulating part, the thermal conductivity of the at least two heat-conducting regions decreases sequentially.

8. The battery cell according to claim 7, characterized in that, The second insulating portion includes a first portion and a second portion connected together, the first portion being disposed along a second direction with the electrode assembly and connected to the edge of the first insulating portion along the second direction; The second part is disposed along a third direction with the electrode assembly and is connected to the edge of the first insulating part along the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other; At least one of the first portion and the second portion includes the at least two heat-conducting zones.

9. The battery cell according to claim 8, characterized in that, The area of ​​the first part is larger than the area of ​​the second part, and the first part includes the at least two heat-conducting areas.

10. The battery cell according to claim 7, characterized in that, The difference in thermal conductivity between two adjacent heat-conducting zones is 0.01 W / mK to 20 W / mK.

11. The battery cell according to claim 10, characterized in that, The difference in thermal conductivity between two adjacent heat-conducting zones is 0.05 W / mK to 10 W / mK.

12. The battery cell according to claim 1, characterized in that, The thickness of the first insulating part is 0.02mm-0.6mm.

13. The battery cell according to claim 12, characterized in that, The thickness of the first insulating part is 0.05mm-0.3mm.

14. The battery cell according to claim 1, characterized in that, The first wall supports the electrode assembly, and the battery cell further includes a base plate disposed between the first insulating part and the first wall.

15. The battery cell according to claim 14, characterized in that, The thermal conductivity of the base plate is greater than that of the second insulating part.

16. The battery cell according to claim 14, characterized in that, The thickness of the base plate is 0.05mm-6mm.

17. The battery cell according to claim 16, characterized in that, The thickness of the base plate is 0.1mm-3mm.

18. The battery cell according to any one of claims 1-17, characterized in that, The electrode assembly includes an electrode body and a tab. The tab extends from one end face of the electrode body. The first wall is located on the side of the electrode body opposite to the tab. The first insulating portion is disposed between the first wall and the electrode body.

19. The battery cell according to any one of claims 1-17, characterized in that, The electrode assembly includes an electrode body and a tab. The tab extends from one end face of the electrode body along a first direction. The first wall and the electrode assembly are disposed along a second direction. The first insulating portion is disposed between the first wall and the electrode body. The first direction intersects the second direction.

20. The battery cell according to claim 19, characterized in that, The housing also includes a second wall, which is disposed along a third direction with the electrode assembly, and the first direction, the second direction, and the third direction are perpendicular to each other; The first wall is connected to the second wall, the area of ​​the first wall is larger than the area of ​​the second wall, and at least a portion of the second insulating portion is disposed between the electrode body and the second wall.

21. A battery device, characterized in that, It includes multiple battery cells as described in any one of claims 1-20.

22. The battery device according to claim 21, characterized in that, The battery device also includes a heat exchanger, which is attached to the first wall.

23. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-20 or a battery device as described in claim 21 or 22, wherein the battery cell or the battery device is used to store or provide electrical energy.

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