An electric cell, a battery pack, and a vehicle

Abstract

The application relates to the technical field of batteries, in particular to a battery cell, a battery pack and a vehicle. The battery cell comprises a shell, a pole core and a heat conduction layer. The shell comprises a narrow side wall, a wide side wall and an arc-shaped side wall, and the arc-shaped side wall is connected to the narrow side wall and the wide side wall. The pole core is located in the interior of the shell, a large surface and the wide side wall are oppositely arranged, and a mounting space is formed among a narrow surface, the arc-shaped side wall and the narrow side wall. The heat conduction layer is arranged in the mounting space formed by the narrow surface, the arc-shaped side wall and the narrow side wall of the pole core. An efficient heat conduction path is formed between the narrow surface of the pole core and the narrow side wall, the heat conduction capacity of the narrow surface of the pole core is improved, the large surface of the pole core and the wide side wall are oppositely arranged, in the cycle process of charging and discharging, the large surface of the pole core can be in contact with the wide side wall after expansion, heat is quickly and unobstructedly transferred to the shell, and the heat conduction layer is not arranged between the large surface of the pole core and the wide side wall, so that the energy density of the battery cell is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery cell, a battery pack, and a vehicle. Background Technology

[0002] As the primary power source for electric vehicles, the thermal management of battery cells is crucial. Effective thermal management not only improves cell performance and lifespan but also ensures cell safety.

[0003] Currently, common cooling methods for battery cells include air cooling, liquid cooling, phase change material cooling, and heat pipe cooling. The cooling principle involves the cooling medium directly or indirectly contacting the battery cell, using the temperature difference to transfer heat between the cooling medium and the battery cell. During operation, the heat source of the battery cell is the metal mechanical parts and the electrode core containing the positive and negative electrode active materials; the casing does not generate heat. However, the casing is the interface between hot and cold surfaces. To ensure a high temperature difference at this interface, the heat from the electrode core must be transferred to the casing quickly and unimpeded.

[0004] To ensure the electrode core can be smoothly inserted into the casing, its size is usually slightly smaller than the casing. Furthermore, to avoid sharp edges on the casing, reduce edge stress, and improve mechanical strength, the right-angled edges of the casing are often rounded. Due to the limitations of the current collector and the presence of the rounded corners, the narrow facet of the electrode core cannot completely contact the casing, resulting in an air gap layer. This makes it difficult for the narrow facet of the electrode core to transfer heat to the casing, leading to insufficient overall thermal conductivity of the cell. Utility Model Content

[0005] The purpose of this application is to provide a battery cell, battery pack, and vehicle that improves the thermal conductivity of the battery cell.

[0006] To solve the above-mentioned technical problems, this application provides a battery cell, comprising:

[0007] A housing, the housing including a narrow sidewall, a wide sidewall and an arcuate sidewall, the arcuate sidewall connecting the narrow sidewall and the wide sidewall;

[0008] The pole core is located inside the housing. The pole core includes a narrow surface and a large surface. The large surface and the wide sidewall are arranged opposite to each other. The narrow surface, the arc-shaped sidewall and the narrow sidewall form an installation space.

[0009] A heat-conducting layer is provided in the installation space.

[0010] This application's battery cell incorporates a thermally conductive layer within the mounting space formed between the narrow face, curved sidewall, and narrow sidewall of the electrode core. Utilizing the physical filling effect of a highly thermally conductive material, the previously inefficient air medium is replaced with a highly thermally conductive medium. This thins the air gap layer caused by the presence of the radius (R-angle) and the constraint of the current collector, thereby creating a highly efficient heat conduction path between the narrow face of the electrode core and the narrow sidewall of the casing. This significantly reduces the thermal resistance of the narrow face of the electrode core, fully leveraging its ability to more easily transfer heat to the casing, thus greatly improving the thermal conductivity of the narrow face of the electrode core, significantly enhancing the overall thermal conductivity of the battery cell, improving overall heat dissipation balance, and improving the performance and lifespan of the battery cell. Simultaneously, the large face of the electrode core and the wide sidewall are positioned opposite each other. During charge-discharge cycles, the large face of the electrode core expands and contacts the wide sidewall, allowing heat to be quickly and unimpededly transferred to the casing. Therefore, this application eliminates the need for a thermally conductive layer between the large face of the electrode core and the wide sidewall, effectively increasing the energy density of the battery cell.

[0011] Optionally, the radius of the arc-shaped sidewall is R, and the thickness of the heat-conducting layer is d, wherein the value of d is in the range of: R-1≤d≤R.

[0012] Optionally, the range of values ​​for d is: R-1≤d≤R-0.5.

[0013] Optionally, the heat-conducting layer has a porous structure, with at least a portion of the porous structure penetrating the outer surface of the heat-conducting layer.

[0014] Optionally, the percentage of the ratio of the total volume of the pore structure to the apparent volume of the thermally conductive layer is P1, and the percentage of the ratio of the volume of the free electrolyte in the cell to the apparent volume of the thermally conductive layer is P2, where P1 > P2.

[0015] Optionally, the heat-conducting layer is movably disposed between the narrow face and the narrow sidewall, or the heat-conducting layer is connected to the housing.

[0016] Optionally, the thermally conductive layer is made of a compressible material;

[0017] And / or, the thermally conductive layer is made of a porous material.

[0018] Optionally, the thermally conductive layer is made of porous carbon nanotube composite material.

[0019] Optionally, the thermally conductive layer includes an inner thermally conductive layer near the narrow face and an outer thermally conductive layer near the narrow sidewall, wherein the compressibility of the inner thermally conductive layer is greater than that of the outer thermally conductive layer.

[0020] Optionally, the outer thermal conductive layer is made of a porous ceramic material;

[0021] And / or, the inner thermally conductive layer is made of porous carbon nanotube composite material.

[0022] This application also provides a battery pack including the aforementioned battery cells.

[0023] The battery pack of this application includes the aforementioned battery cell, and therefore has the same technical effects as the aforementioned battery cell, which will not be repeated here.

[0024] This application also provides a vehicle including the aforementioned battery pack.

[0025] The vehicle in this application includes the aforementioned battery pack, and therefore has the same technical effects as the aforementioned battery pack, which will not be repeated here. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a specific embodiment of the battery cell provided in this application;

[0027] Figure 2 for Figure 1 A partial cross-sectional view of the area where the thermal conductive layer is located in the battery cell;

[0028] in, Figures 1-2 The accompanying figure labels are as follows:

[0029] 1-Shell; 11-Narrow sidewall; 12-Wide sidewall; 13-Arc-shaped sidewall;

[0030] 2-Core; 21-Narrow facet; 22-Large facet;

[0031] 3-Heat-conducting layer; 31-Inner heat-conducting layer; 32-Outer heat-conducting layer. Detailed Implementation

[0032] 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.

[0033] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0034] It should be understood that the phrase "some embodiments" throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "some embodiments" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0035] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0036] As the primary power source for portable and electric vehicles, the thermal management of battery cells is crucial. Effective thermal management not only improves cell performance and lifespan but also ensures cell safety. Battery cells generate heat during charging and discharging; excessively high temperatures can damage the cells or even cause fires or explosions. Therefore, implementing effective thermal management measures is key to maintaining stable cell operation. By employing technologies such as heat dissipation systems, temperature monitoring, and control systems, the temperature of the battery cells can be effectively controlled, maintaining their operating temperature within a safe range.

[0037] Currently, common cooling methods for battery cells include air cooling, liquid cooling, phase change material cooling, and heat pipe cooling. The cooling principle involves the cooling medium directly or indirectly contacting the battery cell, utilizing the temperature difference to transfer heat between the cooling medium and the battery cell. According to Newton's law of cooling, the greater the temperature difference, the faster the heat transfer. Therefore, maintaining a constant high temperature difference at the interface between the cooling medium and the battery cell is the optimal state for thermal management. During operation, the heat source of the battery cell is the metal mechanical parts and the electrode core containing the positive and negative electrode active materials; the casing does not generate heat. However, the casing is the interface between hot and cold materials. To ensure a high temperature difference at the interface, the heat from the electrode core must be able to be quickly and unimpededly transferred to the casing.

[0038] Commonly used battery cell shapes include square, cylindrical, and pouch cells, with the square shape being the most prevalent due to its advantages such as high energy density, strong structural stability, simple manufacturing process, and low resistance. To avoid sharp edges, reduce edge stress, and improve mechanical strength, the right-angled edges of square cells are often rounded. Due to the limitations of the current collector and the presence of the rounded corners, the narrow facet of the electrode cannot completely contact the casing, resulting in an air gap between the narrow facet of the electrode and the narrow sidewall of the casing. This makes it difficult for the narrow facet to transfer heat to the casing, leading to insufficient overall thermal conductivity of the battery cell.

[0039] The electrode core is composed of a sandwich structure consisting of a copper foil layer, a negative electrode layer, a separator layer, a positive electrode layer, and an aluminum foil layer connected in parallel. Because the metal material has a higher thermal conductivity than the active material layer, the thermal conductivity of the electrode core along the stretching direction of the metal foil is significantly higher than the thermal conductivity of the metal foil in the normal direction. In other words, the narrower surface has a higher thermal conductivity than the larger surface area.

[0040] Based on this, this application provides a battery cell that utilizes the characteristic of the narrow surface of the electrode core having greater thermal conductivity to improve the overall thermal conductivity of the battery cell.

[0041] Please refer to Figures 1-2 , Figure 1 This is a schematic diagram of the structure of a specific embodiment of the battery cell provided in this application; Figure 2 for Figure 1 A partial cross-sectional view of the area where the thermal conductive layer is located in the battery cell.

[0042] This embodiment describes a battery cell, comprising:

[0043] The housing 1 includes a narrow sidewall 11, a wide sidewall 12 and an arc-shaped sidewall 13, with the arc-shaped sidewall 13 connecting the narrow sidewall 11 and the wide sidewall 12.

[0044] The pole core 2 is located inside the housing 1. The pole core 2 includes a narrow surface 21 and a large surface 22. The large surface 22 and the wide side wall 12 are arranged opposite to each other. The narrow surface 21, the arc side wall 13 and the narrow side wall 11 form an installation space.

[0045] Thermal conductive layer 3 is installed in the installation space.

[0046] In this embodiment, a thermally conductive layer 3 is provided in the mounting space enclosed by the narrow face 21, arc-shaped sidewall 13, and narrow sidewall 11 of the electrode core 2. By utilizing the physical filling effect of the high thermal conductivity material, the originally inefficient air medium is replaced with a high thermal conductivity medium, and the air gap layer caused by the presence of the R-angle and the constraint of the current collector is thinned. This forms an efficient heat conduction path between the narrow face 21 of the electrode core 2 and the narrow sidewall 11 of the shell 1, which greatly reduces the thermal resistance of the narrow face 21 of the electrode core 2. It also makes full use of the greater thermal conductivity of the narrow face 21 of the electrode core 2, greatly improves the thermal conductivity of the narrow face 21 of the electrode core 2, greatly improves the overall thermal conductivity of the battery cell, improves the overall heat dissipation balance, and improves the performance and service life of the battery cell.

[0047] Meanwhile, the large surface 22 and the wide sidewall 12 of the electrode core 2 are arranged opposite to each other. During the charging and discharging cycle, the large surface 22 of the electrode core 2 can directly contact the wide sidewall 12 after expansion, so that heat can be quickly and unimpededly transferred to the shell 1. Therefore, in this embodiment, no heat-conducting layer 3 is provided between the large surface 22 and the wide sidewall 12 of the electrode core 2, which effectively improves the energy density of the battery cell.

[0048] Depend on Figure 1 and Figure 2 It can be seen that the radius of the arc-shaped sidewall 13 is R, and the thickness of the heat-conducting layer 3 is d. The range of d is: R-1≤d≤R.

[0049] Verification showed that if d > R, the thickness of the heat-conducting layer 3 is too thick, affecting its assemblability; if d < R-1, the thickness of the heat-conducting layer 3 is too thin, and it cannot fully fill the space between the narrow face 21 of the pole core 2 and the narrow sidewall 11 of the shell 1. The air gap between the narrow face 21 of the pole core 2 and the narrow sidewall 11 of the shell 1 remains thick, the thermal resistance of the narrow face 21 of the pole core 2 remains high, and the thermal conductivity of the narrow face 21 of the pole core 2 cannot be fully improved. However, if d has the above value range, while ensuring the assemblability of the heat-conducting layer 3, it can fully fill the space between the narrow face 21 of the pole core 2 and the narrow sidewall 11 of the shell 1, reducing the air gap between the narrow face 21 of the pole core 2 and the narrow sidewall 11 of the shell 1, significantly reducing the thermal resistance of the narrow face 21 of the pole core 2, and effectively improving the thermal conductivity of the narrow face 21 of the pole core 2.

[0050] Specifically, d can take values ​​such as R, R-0.2, R-0.4, R-0.6, R-0.8, R-1, etc. When d is R, the inner surface of the heat-conducting layer 3 is bonded to the narrow surface 21 of the pole core 2, and the outer surface of the heat-conducting layer 3 is bonded to the inner surface of the narrow sidewall 11 of the shell 1. The air gap between the narrow surface 21 of the pole core 2 and the narrow sidewall 11 of the shell 1 is completely replaced by the heat-conducting layer 3. This ensures the assemblability of the heat-conducting layer 3 while maximizing the... The thermal conductivity of the narrow surface 21 of the electrode core 2 is significantly improved. When d is R-1, the thermal resistance of the narrow surface 21 of the electrode core 2 is greatly reduced, and the thermal conductivity of the narrow surface 21 of the electrode core 2 is effectively improved. At the same time, the assemblability of the thermal conductive layer 3 is the best, improving the assembly efficiency of the thermal conductive layer 3 and improving the production efficiency of the battery cell. When d is R-0.2, R-0.4, R-0.6, R-0.8, the assemblability and thermal conductivity of the thermal conductive layer 3 can be better balanced.

[0051] Furthermore, in some embodiments of this application, the value range of d is: R-1≤d≤R-0.5.

[0052] As set above, d can specifically take values ​​of R-0.5, R-0.6, R-0.7, R-0.8, R-0.9, and R-1. This significantly reduces the thermal resistance of the narrow surface 21 of the electrode core 2, effectively improves the thermal conductivity of the narrow surface 21 of the electrode core 2, and at the same time helps to further improve the assemblability of the thermal conductive layer 3, further improve the assembly efficiency of the thermal conductive layer 3, and further improve the production efficiency of the battery cell.

[0053] Furthermore, the heat-conducting layer 3 has a porous structure, with at least a portion of the porous structure penetrating the outer surface of the heat-conducting layer 3.

[0054] As set up above, the porous structure of the thermal conductive layer 3 can be used to adsorb free electrolyte. The size, shape, and porosity of the porous structure of the thermal conductive layer 3 need to be designed according to the amount of free electrolyte in the battery cell to ensure that the free electrolyte can be completely adsorbed in the pores and to ensure the electrolyte retention capacity of the battery cell.

[0055] The porosity of the thermally conductive layer 3 is defined as the percentage ratio of the total volume of the pore structure to the apparent volume of the thermally conductive layer 3. P1 is defined as the percentage ratio of the total volume of the pore structure to the apparent volume of the thermally conductive layer 3, and P2 is defined as the percentage ratio of the volume of the free electrolyte in the cell to the apparent volume of the thermally conductive layer 3, where P1 > P2. This ensures that the free electrolyte can be completely adsorbed within the pores, guaranteeing the cell's electrolyte retention capacity.

[0056] As mentioned above, the heat-conducting layer 3 is located between the narrow face 21 and the narrow sidewall 11. In some embodiments, the heat-conducting layer 3 can be movably disposed between the narrow face 21 and the narrow sidewall 11. During assembly, the electrode core 2 can be installed into the housing 1 first, and then the heat-conducting layer 3 can be placed between the narrow face 21 and the narrow sidewall 11. In this way, the heat-conducting layer 3 and the housing 1 are separate structures, and the appropriate thickness of the heat-conducting layer 3 can be selected according to the size of the housing 1 and the electrode core 2, making the placement of the heat-conducting layer 3 more flexible. At the same time, the heat-conducting layer 3 is in a movable state, allowing the heat-conducting layer 3 to shift as the electrode core 2 expands, minimizing compression of the electrode core 2 and minimizing damage to its structure.

[0057] In some other embodiments, the heat-conducting layer 3 can be connected to the housing 1 first, and then the electrode core 2 can be inserted into the housing. In this way, the heat-conducting layer 3 is in a fixed state, which helps to improve the positional stability of the heat-conducting layer 3 and the stability of its heat conduction capability.

[0058] The heat-conducting layer 3 is connected to the housing 1, either to the bottom wall of the housing 1 or to the narrow side wall 11 of the housing 1. The specific connection method is not limited, such as welding.

[0059] Furthermore, the heat-conducting layer 3 is made of a compressible material.

[0060] As set up above, since the inner surface of the heat-conducting layer 3 is close to the active material of the electrode core 2, in order to avoid hard contact between the heat-conducting layer 3 and the active material that expands during charging and discharging, the heat-conducting layer 3 is compressible, so as to avoid damaging the structure of the electrode core 2 as much as possible and ensure the performance of the electrode core 2.

[0061] Among them, a compressible material is one whose strain is greater than 20% when subjected to a stress of 0.04 MPa.

[0062] Furthermore, the thermal conductive layer 3 is made of a porous material.

[0063] As described above, the thermal conductive layer 3 is made of a porous material, which facilitates the formation of the aforementioned pore structure in the thermal conductive layer 3. The pore structure can be used to adsorb free electrolyte, so that the free electrolyte can be completely adsorbed in the pore structure, ensuring the electrolyte retention capacity of the battery cell.

[0064] Of course, the heat-conducting layer 3 should also have high thermal conductivity to ensure that the heat from the narrow surface 21 of the pole core 2 can be quickly and smoothly transferred to the shell 1; at the same time, the heat-conducting layer 3 should also have insulation (conductivity < 10). -7 The heat-conducting layer 3 is characterized by its high temperature resistance (>1600℃) and corrosion resistance, ensuring structural stability and avoiding short-circuit risks.

[0065] High thermal conductivity means that the thermal conductivity of the heating layer 3 is not less than 20 W / (m·K).

[0066] In some embodiments of this application, the thermally conductive layer 3 is made of porous carbon nanotube composite material.

[0067] Porous carbon nanotube composites are a mature and readily available material. They are formed by embedding carbon nanotubes into a porous insulating substrate. Porous carbon nanotube composites combine the advantages of carbon nanotubes and porous materials, maintaining the thermal conductivity of carbon while increasing the material's ductility. The unique structure and high strength of carbon nanotubes give porous carbon nanotube composites excellent compressibility and thermal conductivity. The porous structure of the composite material is used to adsorb free electrolyte, ensuring the electrolyte retention capacity of the battery cell. Simultaneously, porous carbon nanotube composites also possess good insulation, high-temperature resistance, and corrosion resistance. The thermally conductive layer 3 is made of porous carbon nanotube composite material, ensuring its long-term stable and efficient heat conduction.

[0068] Of course, the thermally conductive layer 3 is not limited to the aforementioned porous carbon nanotube composite materials. For example, the thermally conductive layer 3 can also be a graphene / silicone rubber composite elastomer material, a silicon-based composite material, etc.

[0069] Please continue to refer to this. Figure 2 In some embodiments of this application, the heat-conducting layer 3 includes an inner heat-conducting layer 31 near the narrow surface 21 and an outer heat-conducting layer 32 near the narrow sidewall 11, wherein the compressibility of the inner heat-conducting layer 31 is greater than that of the outer heat-conducting layer 32.

[0070] As described above, in this embodiment, the heat-conducting layer 3 is designed as an inner and outer double-layer structure. The compressibility of the inner heat-conducting layer 31 is greater than that of the outer heat-conducting layer 32, so that the inner heat-conducting layer 31 can absorb the expansion stress of the active material through flexible deformation, and avoid hard contact between the heat-conducting layer 3 and the active material that expands during charging and discharging as much as possible, and avoid rigid pressure that could damage the structure of the electrode core 2. At the same time, the outer heat-conducting layer 32 can maintain a stable thermal interface contact pressure, ensuring that heat is efficiently transferred to the narrow sidewall 11 of the shell 1, and ensuring that the heat-conducting layer 3 has a stable and efficient heat conduction capability.

[0071] The compressibility of the inner heat-conducting layer 31 should satisfy the following: when the stress on the inner heat-conducting layer 31 is 0.04 MPa, the strain should be greater than 20%. The compressibility of the outer heat-conducting layer 32 should satisfy the following: when the stress on the inner heat-conducting layer 31 is 0.04 MPa, the strain should not be greater than 20%.

[0072] The inner heat-conducting layer 31 and the outer heat-conducting layer 32 can be independent structures or connected to each other. The specific connection method is not limited. For example, the inner heat-conducting layer 31 and the outer heat-conducting layer 32 can be fixed by welding, bonding, etc.

[0073] Furthermore, both the inner heat-conducting layer 31 and the outer heat-conducting layer 32 are made of porous materials.

[0074] As configured above, the inner thermally conductive layer 31 and the outer thermally conductive layer 32 more easily form the aforementioned porous structure for adsorbing free electrolyte. The size, shape, and porosity of the porous structure of the inner thermally conductive layer 31 and the outer thermally conductive layer 32 need to be designed according to the amount of free electrolyte in the battery cell to ensure that the free electrolyte can be completely adsorbed in the pores and to ensure the electrolyte retention capacity of the battery cell.

[0075] Of course, both the inner heat-conducting layer 31 and the outer heat-conducting layer 32 should have high thermal conductivity to ensure that the heat of the narrow surface 21 of the core 2 can be quickly and unimpededly transferred to the shell 1; at the same time, the inner heat-conducting layer 31 and the outer heat-conducting layer 32 should also have insulation, high temperature resistance and corrosion resistance to ensure the structural stability of the heat-conducting layer 3 and avoid the risk of short circuit.

[0076] If the thermal conductivity of the inner heat-conducting layer 31 is greater than 20 W / (m·K), and the electrical conductivity of the inner heat-conducting layer 31 is less than 10 W / (m·K), then... -7 S / cm, the inner thermal conductive layer 31 can withstand high temperatures of at least 1600°C.

[0077] In some embodiments of this application, the outer thermal conductive layer 32 is made of porous ceramic material.

[0078] Porous ceramic materials are a class of ceramic materials with a large number of pores. They have good thermal conductivity and can withstand high temperatures, making them suitable for applications in high-temperature environments. Porous ceramic materials usually have good chemical stability and are not prone to reacting with the medium. At the same time, porous ceramic materials also have good mechanical stability.

[0079] Porous ceramic materials also possess strong corrosion resistance, thermal conductivity (thermal conductivity > 2 W / (m·K)) and insulation properties (electrical conductivity < 10). -13 (S / cm), etc.

[0080] The outer thermal conductive layer 32 can be made of materials such as porous alumina ceramic, porous aluminum nitride ceramic, and porous silicon carbide ceramic.

[0081] In some embodiments of this application, the inner thermally conductive layer 31 is made of porous carbon nanotube composite material.

[0082] Porous carbon nanotube composites are a mature material currently available. They are formed by embedding carbon nanotubes into a porous insulating substrate. Porous carbon nanotube composites combine the advantages of carbon nanotubes and porous materials, increasing the compressibility of the material while maintaining the thermal conductivity of carbon. The special structure and high strength of carbon nanotubes give porous carbon nanotube composites excellent compressibility and thermal conductivity. The porous structure of the porous carbon nanotube composite is used to adsorb free electrolyte, ensuring the electrolyte retention capacity of the battery cell. Simultaneously, porous carbon nanotube composites also possess good insulation, high-temperature resistance, and corrosion resistance. The inner thermal conductive layer 31 is made of porous carbon nanotube composite material, ensuring that the inner thermal conductive layer 31 can stably and efficiently conduct heat over a long period.

[0083] Of course, the inner thermal conductive layer 31 is not limited to the aforementioned porous carbon nanotube composite materials. For example, the inner thermal conductive layer 31 can also be a graphene / silicone rubber composite elastomer material, a silicon-based composite material, etc.

[0084] This embodiment also provides a battery pack, including the aforementioned battery cells.

[0085] The battery pack of this embodiment includes the aforementioned battery cells, and therefore has the same technical effects as the aforementioned battery cells, which will not be repeated here.

[0086] This embodiment also provides a vehicle including the aforementioned battery pack.

[0087] The vehicle in this embodiment includes the aforementioned battery pack, and therefore has the same technical effects as the aforementioned battery pack, which will not be repeated here.

[0088] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A battery cell, characterized in that, include: The housing (1) includes a narrow sidewall (11), a wide sidewall (12) and an arcuate sidewall (13), the arcuate sidewall (13) connecting the narrow sidewall (11) and the wide sidewall (12). The pole core (2) is located inside the housing (1). The pole core (2) includes a narrow surface (21) and a large surface (22). The large surface (22) and the wide side wall (12) are arranged opposite to each other. The narrow surface (21), the arc-shaped side wall (13) and the narrow side wall (11) form an installation space. A heat-conducting layer (3) is provided in the installation space.

2. The battery cell according to claim 1, characterized in that, The radius of the arc-shaped sidewall (13) is R, and the thickness of the heat-conducting layer (3) is d. The value range of d is: R-1≤d≤R.

3. The battery cell according to claim 2, characterized in that, The range of values ​​for d is: R-1≤d≤R-0.

5.

4. The battery cell according to any one of claims 1-3, characterized in that, The heat-conducting layer (3) has a porous structure, and at least part of the porous structure penetrates the outer surface of the heat-conducting layer (3).

5. The battery cell according to claim 4, characterized in that, The percentage of the ratio of the total volume of the pore structure to the apparent volume of the heat-conducting layer (3) is P1, and the percentage of the ratio of the volume of the free electrolyte in the cell to the apparent volume of the heat-conducting layer (3) is P2, where P1 > P2.

6. The battery cell according to any one of claims 1-3, characterized in that, The heat-conducting layer (3) is movably disposed in the installation space; or, the heat-conducting layer (3) is connected to the housing (1).

7. The battery cell according to any one of claims 1-3 and 5, characterized in that, The heat-conducting layer (3) is made of a compressible material; And / or, the thermally conductive layer is made of a porous material.

8. The battery cell according to claim 4, characterized in that, The heat-conducting layer (3) is made of a compressible material; And / or, the thermally conductive layer is made of a porous material.

9. The battery cell according to claim 6, characterized in that, The heat-conducting layer (3) is made of a compressible material; And / or, the thermally conductive layer is made of a porous material.

10. The battery cell according to claim 7, characterized in that, The thermally conductive layer (3) is made of porous carbon nanotube composite material.

11. The battery cell according to any one of claims 1-3 and 5, characterized in that, The heat-conducting layer (3) includes an inner heat-conducting layer (31) near the narrow face (21) and an outer heat-conducting layer (32) near the narrow sidewall (11), wherein the compressibility of the inner heat-conducting layer (31) is greater than that of the outer heat-conducting layer (32).

12. The battery cell according to claim 4, characterized in that, The heat-conducting layer (3) includes an inner heat-conducting layer (31) near the narrow face (21) and an outer heat-conducting layer (32) near the narrow sidewall (11), wherein the compressibility of the inner heat-conducting layer (31) is greater than that of the outer heat-conducting layer (32).

13. The battery cell according to claim 6, characterized in that, The heat-conducting layer (3) includes an inner heat-conducting layer (31) near the narrow face (21) and an outer heat-conducting layer (32) near the narrow sidewall (11), wherein the compressibility of the inner heat-conducting layer (31) is greater than that of the outer heat-conducting layer (32).

14. The battery cell according to claim 11, characterized in that, The outer heat-conducting layer (32) is made of porous ceramic material; And / or, the inner thermal conductive layer (31) is made of porous carbon nanotube composite material.

15. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1-14.

16. A vehicle, characterized in that, Includes the battery pack as described in claim 15.

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