Battery pack and electric device

Abstract

The application discloses a battery pack and an electric equipment, and belongs to the technical field of batteries, wherein the battery pack comprises a box body, a battery cell module and a first phase change material piece, an inner wall of the box body comprises a top wall; the battery cell module comprises a plurality of battery cells and an integrated busbar, the battery cells are installed in the box body, the integrated busbar is electrically connected with the plurality of battery cells, and the integrated busbar is arranged at one end of the battery cells, which faces the top wall; and the first phase change material piece is at least partially arranged between the integrated busbar and the top wall. The first phase change material piece absorbs the heat of the integrated busbar through the phase change property, and transmits the absorbed heat to the top wall of the box body. The large-area natural heat dissipation of the top wall makes up for the insufficient heat exchange capacity of the top of the battery cell, delays the temperature rising rate of the top of the battery cell, and in turn reduces the temperature difference between the top and the bottom of the battery cell, prolongs the service life of the battery cell, ensures the stability of the battery cell, and reduces the probability of thermal runaway of the battery cell.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery pack and electrical device. Background Technology

[0002] Currently, the thermal management technology of power battery systems usually involves installing a liquid cooling plate at the bottom of the battery pack. The battery pack and the liquid cooling plate are independent components. The heat generated by the battery in the battery pack during use is transferred to the liquid cooling plate for heat dissipation through the bottom of the battery pack.

[0003] In the prior art, the terminals of the cells in the battery pack are connected by an integrated busbar. The integrated busbar is located on top of the cell and carries a large current, which results in a high temperature at the top of the cell and a large temperature difference between the top and bottom of the cell, affecting the lifespan of the battery pack. Utility Model Content

[0004] This application provides a battery pack to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a battery pack is provided, comprising: The enclosure, the inner wall of which includes a top wall; A battery cell module, comprising multiple battery cells and an integrated busbar, wherein the battery cells are installed within the housing, the integrated busbar is electrically connected to the multiple battery cells, and the integrated busbar is located at the end of the battery cells facing the top wall; and, A first phase change material component is disposed at least partially between the integrated busbar and the top wall.

[0006] Optionally, the integrated busbar includes a support and a busbar, and the first phase change material component is thermally connected to the busbar; and / or, The first phase change material component is thermally connected to the electrode post of the battery cell; and / or, The first phase change material component is thermally connected to the top wall.

[0007] By connecting the first phase change material to the busbar for thermal conductivity, heat on the busbar is absorbed, improving heat exchange efficiency and thus better reducing the temperature at the top of the cell, ensuring the stability of the battery pack.

[0008] Optionally, the thickness of the first phase change material component is greater than or equal to 10 mm and less than or equal to 20 mm.

[0009] By setting the thickness of the first phase change material component within a suitable range, the cooling effect on the top of the battery cell is ensured while minimizing the impact of the first phase change material on the battery pack volume, thereby improving the stability of the battery pack.

[0010] Optionally, the battery pack further includes a first thermally conductive layer disposed between the first phase change material component and the integrated busbar; and / or, The battery pack also includes a second thermally conductive layer, which is disposed between the first phase change material component and the top wall.

[0011] By setting a first thermally conductive layer and / or a second thermally conductive layer, the heat exchange efficiency between the first phase change material component and the top wall or integrated busbar is improved, thereby enhancing the cooling effect on the top of the battery cell. Furthermore, the thermally conductive layer allows the heat from the integrated busbar to be evenly absorbed into the first phase change material component, reducing the probability of localized overheating. The heat from the first phase change material component can also be evenly distributed to the top wall, improving the heat dissipation efficiency of the top wall.

[0012] Optionally, the battery pack further includes at least one second phase change material element, and the second phase change material element is provided on at least a portion of one side surface of the cell in the thickness direction.

[0013] By setting the second phase change material component on one side of the cell in the thickness direction, that is, connecting the larger side of the cell to the second phase change material component, the heat generated by the electrochemical reaction inside the cell can be absorbed into the second phase change material component more quickly, thereby regulating the temperature of the cell.

[0014] Optionally, the thickness of the second phase change material component is greater than or equal to 1 mm and less than or equal to 3 mm.

[0015] By setting the thickness of the second phase change material component within a suitable range, the cooling effect on the battery cell can be guaranteed while minimizing the impact of the second phase change material on the battery pack volume. This improves the stability of the battery pack and reduces the probability of thermal runaway in the battery cell.

[0016] Optionally, the battery cell includes a first end face and a second end face, wherein the first end face and the second end face are disposed opposite to each other along the thickness direction of the battery cell; The battery pack further includes a protective layer, and at least a portion of the battery cells have a protective layer on their first end face and a second phase change material component on their second end face.

[0017] By setting up a protective layer, when thermal runaway occurs in some cells within the battery module, the protective layer can separate the runaway cells from the normal cells, preventing the spread of thermal runaway and improving the safety of the battery pack.

[0018] Optionally, the protective layer includes a heat insulation layer; Along the length of the battery cell module, the heat insulation layer is provided between two adjacent battery cells.

[0019] By setting up a heat insulation layer, when a cell experiences thermal runaway, the heat is blocked by the heat insulation layer and cannot be conducted to adjacent cells, thereby protecting other normal cells and improving the safety of the battery pack.

[0020] Optionally, the inner wall of the housing further includes a bottom wall, which is disposed opposite to the top wall to support the battery cell module; The battery pack also includes a third thermally conductive layer, which is disposed between the second phase change material component and the bottom wall.

[0021] By setting a third heat-conducting layer, the heat absorbed by the second phase change material component can be conducted to the bottom wall through the third heat-conducting layer, thereby dissipating heat with the help of the bottom wall. This allows the heat inside the second phase change material component to be transferred to the outside of the battery pack more quickly, thereby improving the cooling effect of the second phase change material component on the battery cell and ensuring the safety and stability of the battery pack.

[0022] Optionally, the third thermally conductive layer is also disposed between the battery cell and the bottom wall.

[0023] By setting a third heat-conducting layer between the battery cell and the bottom wall, the heat of the battery cell itself can be directly conducted to the bottom wall, further improving the heat dissipation effect of the battery cell, reducing the temperature of the battery cell, and thus ensuring the stability of the battery pack during operation.

[0024] Optionally, the phase change temperature of the first phase change material component is greater than or equal to 35°C and less than or equal to 50°C; and / or, The phase change temperature of the second phase change material component is greater than or equal to 35°C and less than or equal to 50°C.

[0025] By setting the phase change temperature of the first phase change material component within a suitable range, it is ensured that when the integrated busbar at the top of the battery cell heats up to a certain temperature due to operation, the phase change material can quickly undergo phase change and absorb a large amount of latent heat. This ensures the working efficiency of the battery cell while suppressing the temperature of the integrated busbar from rising further, thereby maintaining the temperature at the top of the battery cell within a safe and efficient working range.

[0026] According to a second aspect of this application, an electrical device is provided, including the battery pack described above.

[0027] This invention absorbs heat from the integrated busbar through the phase change properties of the first phase change material component and transfers the absorbed heat to the top wall of the housing. The large-area natural heat dissipation of the top wall compensates for the insufficient heat exchange capacity of the top of the battery cell, slows down the temperature rise rate of the top of the battery cell, thereby reducing the temperature difference between the top and bottom of the battery cell, extending the service life of the battery cell, ensuring the stability of the battery cell, and reducing the probability of thermal runaway of the battery cell.

[0028] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0031] Figure 1 This is a schematic diagram of the overall structure of the battery pack provided in an exemplary embodiment of this disclosure; Figure 2 yes Figure 1 Top view of the battery pack; Figure 3 yes Figure 1 Exploded view of part of the battery pack structure; Figure 4 yes Figure 2 BB cross-sectional view of the battery pack; Figure 5 yes Figure 4 Enlarged view of point A in the middle.

[0032] Explanation of reference numerals in the attached figures: 1. Battery pack; 11. Box body; 111. Top wall; 112. Bottom wall; 12. Battery cell module; 121. Battery cell; 122. Integrated busbar; 13. First phase change material component; 14. First thermally conductive layer; 15. Second thermally conductive layer; 16. Second phase change material component; 17. Protective layer. Detailed Implementation

[0033] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0034] This application provides a battery pack 1, please refer to... Figures 1 to 3The battery pack 1 includes a housing 11, a cell module 12, and a first phase change material component 13. The inner wall of the housing 11 includes a top wall 111. The cell module 12 includes multiple cells 121 and an integrated busbar 122. The cells 121 are installed inside the housing 11, and the integrated busbar 122 is electrically connected to the multiple cells 121. The integrated busbar 122 is located at the end of the cells 121 facing the top wall 111. The first phase change material component 13 is at least partially disposed between the integrated busbar 122 and the top wall 111.

[0035] Since the integrated busbar 122 serves as the electrical connection element for multiple battery cells 121, it is prone to generating a large amount of heat due to contact resistance and current collection effect under high-rate charging and discharging or abnormal operating conditions, causing the temperature at the top of the battery cell 121 to rise sharply. Meanwhile, the temperature at the bottom of the battery cell 121 is lower due to cooling by the liquid cooling plate, resulting in a large temperature difference between the two ends of the battery cell 121, which can easily lead to a rapid decline in the lifespan of the battery cell 121.

[0036] Therefore, in this embodiment of the invention, a first phase change material component 13 is provided between the integrated busbar 122 and the top wall 111 of the housing 11. When the battery pack 1 is used under high-intensity conditions, the integrated busbar 122 generates a large amount of heat. This heat is absorbed by the first phase change material component 13, causing the phase change material in the first phase change material component 13 to rise in temperature and undergo a phase change, thereby storing heat and reducing the heating rate at the top of the cell 121. At the same time, the heated first phase change material component 13 conducts heat to the top wall 111. Taking advantage of the large area of ​​the top wall 111 and the high airflow outside the battery pack 1, the first phase change material is cooled, further ensuring that the heat generated by the integrated busbar 122 is continuously absorbed, thus improving the stability of the battery pack 1 during operation. Especially when the cell 121 is square, the regular arrangement makes it easier for the first phase change material component 13 to be installed on the integrated busbar 122 on top of the cell 121, increasing the contact area between the two and thus ensuring the heat absorption effect of the first phase change material component 13.

[0037] The first phase change material component 13 is made of a phase change material (PCM). A phase change material is a substance that changes its state of matter while remaining at a constant temperature and can provide latent heat. The process of changing physical properties is called a phase change process, during which the phase change material absorbs or releases a large amount of latent heat. For example, phase change materials can be hydrated salts, molten salts, paraffin wax, alloys, etc. Research and development on phase change materials is quite mature, and the specific material can be selected according to design requirements.

[0038] This embodiment of the invention utilizes the phase change properties of the first phase change material 13 to absorb heat from the integrated busbar 122 and transfers the absorbed heat to the top wall 111 of the housing 11. The large-area natural heat dissipation of the top wall 111 compensates for the insufficient heat exchange capacity of the top of the battery cell 121, slows down the temperature rise rate of the top of the battery cell 121, thereby reducing the temperature difference between the top and bottom of the battery cell 121, extending the service life of the battery cell 121, ensuring the stability of the battery cell 121, and reducing the probability of thermal runaway of the battery cell 121.

[0039] In some alternative embodiments, an insulating film is provided on the outer surface of the first phase change material component 13 to insulate the first phase change material component 13 from the cell 121 and the top cover, thereby ensuring the safety of the battery pack 1.

[0040] In some embodiments, the integrated busbar 122 includes a support and a busbar, and the first phase change material component 13 is thermally connected to the busbar; and / or, the first phase change material component 13 is thermally connected to the terminal post of the battery cell 121; and / or, the first phase change material component 13 is thermally connected to the top wall 111.

[0041] The busbar is the main component in the integrated busbar 122 that enables current conduction and is also a point of heat concentration. Therefore, in this embodiment of the invention, the first phase change material is thermally connected to the busbar to absorb heat from the busbar, improve heat exchange efficiency, and thus better reduce the temperature at the top of the cell 121, ensuring the stability of the battery pack 1. The thermal connection can be either direct contact between the first phase change material 13 and the busbar, or indirect connection via a thermally conductive material; this embodiment of the invention does not impose any limitations on this.

[0042] The terminals of the battery cell 121 are also high-temperature heat-generating areas. The first phase change material component 13 is thermally connected to the terminals of the battery cell 121, allowing heat from the high-temperature terminals to be quickly transferred to the first phase change material component 13, thereby slowing down the temperature rise rate at the top of the battery cell 121. The first phase change material component 13 is thermally connected to the top wall 111, which allows heat from the first phase change material component 13 to be quickly transferred to the top wall 111, improving heat exchange efficiency and transferring heat from the first phase change material component 13 to the top wall 111 and even the outside of the battery pack 1.

[0043] In some embodiments, the thickness of the first phase change material element 13 is greater than or equal to 10 mm and less than or equal to 20 mm.

[0044] If the thickness of the first phase change material component 13 is less than 10mm, the mass of the phase change material inside the first phase change material component 13 is small, and it can absorb less heat, resulting in poor control of the temperature at the top of the cell 121. If the thickness of the first phase change material component 13 is greater than 20mm, it occupies too much volume, resulting in a lower volumetric energy density of the battery pack 1 and higher cost.

[0045] Therefore, in this embodiment of the utility model, the thickness of the first phase change material 13 is set to be greater than or equal to 10 mm and less than or equal to 20 mm. For example, it can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. This ensures that the first phase change material has a small impact on the volume of the battery pack 1, while maintaining the cooling effect on the top of the cell 121, thereby improving the stability of the battery pack 1.

[0046] In some embodiments, please refer to Figures 1 to 3 The battery pack 1 further includes a first thermally conductive layer 14, which is disposed between the first phase change material component 13 and the integrated busbar 122; and / or, the battery pack 1 further includes a second thermally conductive layer 15, which is disposed between the first phase change material component 13 and the top wall 111.

[0047] By setting the first heat-conducting layer 14 and / or the second heat-conducting layer 15, the heat exchange efficiency between the first phase change material component 13 and the top wall 111 or the integrated busbar 122 is improved, thereby enhancing the cooling effect on the top of the battery cell 121. Furthermore, the heat-conducting layers allow the heat from the integrated busbar 122 to be evenly absorbed into the first phase change material component 13, reducing the probability of localized overheating. The heat from the first phase change material component 13 can also be evenly distributed to the top wall 111, improving the heat dissipation efficiency of the top wall 111.

[0048] In some alternative embodiments, the first thermally conductive layer 14 and / or the second thermally conductive layer 15 may be a thermally conductive structural adhesive, thereby serving a thermally conductive function while bonding the first phase change material component 13 between the top wall 111 and the integrated busbar 122.

[0049] In some embodiments, please refer to Figures 1 to 5 The battery pack 1 also includes at least one second phase change material element 16, and the second phase change material element 16 is provided on one side surface of at least a portion of the cell 121 in the thickness direction.

[0050] By providing a second phase change material component 16 on one side surface of the cell 121 in the thickness direction, that is, by connecting the larger side of the cell 121 to the second phase change material component 16, the heat generated by the electrochemical reaction inside the cell 121 can be absorbed into the second phase change material component 16 more quickly, thereby regulating the temperature of the cell 121.

[0051] The arrangement of the second phase change material component 16 is similar to that of the first phase change material component 13, and will not be described again here.

[0052] In some embodiments, the thickness of the second phase change material 16 is greater than or equal to 1 mm and less than or equal to 3 mm.

[0053] If the thickness of the second phase change material component 16 is less than 1 mm, the mass of the phase change material inside the second phase change material component 16 is small, and it can absorb less heat, resulting in a poor heat absorption effect for the battery cell 121. If the thickness of the second phase change material component 16 is greater than 3 mm, it occupies too much volume, which reduces the number of battery cells 121 that can be installed, or makes the battery pack 1 too large, affecting the energy density of the battery pack 1.

[0054] Therefore, in this embodiment of the invention, the thickness of the second phase change material 16 is set to be greater than or equal to 1 mm and less than or equal to 3 mm. For example, it can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.5 mm, or 3 mm. This ensures that the second phase change material has a small impact on the volume of the battery pack 1 while maintaining the cooling effect on the cell 121, thereby improving the stability of the battery pack 1 and reducing the probability of thermal runaway in the cell 121.

[0055] In some embodiments, the cell 121 includes a first end face and a second end face, which are disposed opposite to each other along the thickness direction of the cell 121; wherein, the battery pack 1 further includes a protective layer 17, and at least a portion of the cell 121 has a protective layer 17 on its first end face and a second phase change material component 16 on its second end face.

[0056] By setting the protective layer 17, when thermal runaway occurs in some cells 121 within the cell module 12, the protective layer 17 can isolate the runaway cells 121 from the normal cells 121, preventing the spread of thermal runaway and improving the safety of the battery pack 1. The protective layer 17 can be made of materials such as ceramic materials, engineering plastics, mica sheets, or foam; this embodiment of the invention does not impose any limitations on this.

[0057] In some alternative implementations, please refer to Figures 1 to 5 The arrangement of the battery cell 121, the second phase change material component 16, and the protective layer 17 in the battery cell module 12 is as follows: battery cell 121 - second phase change material component 16 - protective layer 17 - battery cell 121 - second phase change material component 16 - protective layer 17 - ... - battery cell 121 - second phase change material component 16, so that each battery cell 121 has a layer of second phase change material component 16 on its surface, and a protective layer 17 is provided between two adjacent battery cells 121 to improve the safety of the battery pack 1.

[0058] In some embodiments, the protective layer 17 includes a heat insulation layer; along the length direction of the battery module 12, a heat insulation layer is provided between two adjacent battery cells 121.

[0059] By setting up a heat insulation layer, when thermal runaway occurs in cell 121, the heat is blocked by the heat insulation layer and cannot be conducted to adjacent cells 121, thereby protecting other normal cells 121 and improving the safety of battery pack 1.

[0060] The insulation layer is preferably made of aerogel, which has good insulation performance and low cost.

[0061] In some embodiments, the inner wall of the housing 11 further includes a bottom wall 112, which is disposed opposite to the top wall 111 for supporting the battery cell module 12; the battery pack 1 further includes a third thermally conductive layer, which is disposed between the second phase change material 16 and the bottom wall 112.

[0062] By setting a third heat-conducting layer, the heat absorbed by the second phase change material component 16 can be conducted to the bottom wall 112 through the third heat-conducting layer, thereby dissipating heat with the help of the bottom wall 112. This allows the heat inside the second phase change material component 16 to be transferred to the outside of the battery pack 1 more quickly, thereby improving the cooling effect of the second phase change material component 16 on the cell 121 and ensuring the safety and stability of the battery pack 1.

[0063] Preferably, the bottom wall 112 includes a liquid cooling plate, thereby improving the heat dissipation effect of the bottom wall 112 and thus better cooling the second phase change material component 16 and the battery cell 121.

[0064] In some embodiments, a third thermally conductive layer is also disposed between the battery cell 121 and the bottom wall 112.

[0065] By setting a third heat-conducting layer between the cell 121 and the bottom wall 112, the heat of the cell 121 itself can be directly conducted to the bottom wall 112, further improving the heat dissipation effect of the cell 121, reducing the temperature of the cell 121, and thus ensuring the stability of the battery pack 1 during operation.

[0066] Preferably, the third thermally conductive layer is made of thermally conductive structural adhesive, which can conduct heat to the battery cell 121 while bonding the battery cell 121 to the bottom wall 112, thereby improving the stability of the battery cell module 12 installation.

[0067] In some embodiments, the phase change temperature of the first phase change material component 13 is greater than or equal to 35°C and less than or equal to 50°C; and / or, the phase change temperature of the second phase change material component 16 is greater than or equal to 35°C and less than or equal to 50°C.

[0068] Taking the first phase change material component 13 as an example, if the phase change temperature of the first phase change material component 13 is less than 35°C, the cell 121 may remain in a low temperature state for a long time, making it difficult to reach a suitable operating temperature, thereby reducing the charging and discharging efficiency of the battery pack 1; if the phase change temperature of the first phase change material component 13 is greater than 50°C, the temperature of the cell 121 is already at a high level when the first phase change material component 13 is in operation, affecting the lifespan of the cell 121 and posing a significant safety hazard.

[0069] Therefore, in this embodiment of the invention, the phase change temperature of the first phase change material component 13 is set to be greater than or equal to 35°C and less than or equal to 50°C. This ensures that when the integrated busbar 122 at the top of the battery cell 121 heats up to above 35°C due to operation, the phase change material can quickly undergo phase change and absorb a large amount of latent heat. This ensures the working efficiency of the battery cell 121 while suppressing the temperature of the integrated busbar 122 from rising further, thereby maintaining the temperature at the top of the battery cell 121 within a safe and efficient working range.

[0070] According to a second aspect of this disclosure, an electrical device is provided, which includes the battery pack 1 described above. This electrical device possesses all the beneficial effects of the battery pack 1, which will not be elaborated further herein.

[0071] Electrical equipment can be a vehicle, which can be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc. This disclosure does not make any specific limitations in this regard.

[0072] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0073] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0074] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0075] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A battery pack, characterized in that, include: The enclosure, the inner wall of which includes a top wall; A battery cell module, comprising multiple battery cells and an integrated busbar, wherein the battery cells are installed within the housing, the integrated busbar is electrically connected to the multiple battery cells, and the integrated busbar is located at the end of the battery cells facing the top wall; and, A first phase change material component is disposed at least partially between the integrated busbar and the top wall.

2. The battery pack according to claim 1, characterized in that, The integrated busbar includes a support frame and a busbar, and the first phase change material component is thermally connected to the busbar; and / or, The first phase change material component is thermally connected to the electrode post of the battery cell; and / or, The first phase change material component is thermally connected to the top wall.

3. The battery pack according to claim 1, characterized in that, The thickness of the first phase change material component is greater than or equal to 10 mm and less than or equal to 20 mm.

4. The battery pack according to claim 3, characterized in that, The battery pack further includes a first thermally conductive layer disposed between the first phase change material component and the integrated busbar; and / or The battery pack also includes a second thermally conductive layer, which is disposed between the first phase change material component and the top wall.

5. The battery pack according to any one of claims 1 to 4, characterized in that, The battery pack further includes at least one second phase change material component, and the second phase change material component is provided on at least one side surface of the cell in the thickness direction.

6. The battery pack according to claim 5, characterized in that, The thickness of the second phase change material component is greater than or equal to 1 mm and less than or equal to 3 mm.

7. The battery pack according to claim 5, characterized in that, The battery cell includes a first end face and a second end face, which are disposed opposite to each other along the thickness direction of the battery cell. The battery pack further includes a protective layer, and at least a portion of the battery cells have a protective layer on their first end face and a second phase change material component on their second end face.

8. The battery pack according to claim 7, characterized in that, The protective layer includes a heat insulation layer; Along the length of the battery cell module, the heat insulation layer is provided between two adjacent battery cells.

9. The battery pack according to claim 5, characterized in that, The inner wall of the housing also includes a bottom wall, which is disposed opposite to the top wall to support the battery cell module; The battery pack also includes a third thermally conductive layer, which is disposed between the second phase change material component and the bottom wall.

10. The battery pack according to claim 9, characterized in that, The third thermally conductive layer is also disposed between the battery cell and the bottom wall.

11. The battery pack according to claim 5, characterized in that, The phase transition temperature of the first phase change material component is greater than or equal to 35°C and less than or equal to 50°C; and / or, The phase change temperature of the second phase change material component is greater than or equal to 35°C and less than or equal to 50°C.

12. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1 to 11.

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