Battery pack and electric device

Abstract

This application provides a battery pack and electrical device that solves the problem in the prior art where it is difficult to simultaneously optimize bonding reliability and thermal management efficiency when fixing thermal management components through continuous adhesive interfaces. The battery pack includes a battery module, a first adhesive layer, a second adhesive layer, a cold plate, and a heating film. The battery module includes a first surface and a second surface disposed opposite each other along its height direction. The first adhesive layer is disposed on the first surface. The second adhesive layer is disposed on the second surface. The cold plate is disposed on the first surface via the first adhesive layer. The heating film is disposed on the second surface via the second adhesive layer. By providing a first adhesive layer on the first surface to fix the cold plate and a second adhesive layer on the second surface to fix the heating film, this application ensures the necessary mechanical connection strength between the battery module and the cold plate and heating film, while also providing an effective heat transfer path for battery cooling and heating through the adhesive layers, dispersing interface stress, and optimizing thermal management efficiency.

Description

Technical Field

[0001] This application relates to the field of battery pack thermal management technology, specifically to a battery pack and electrical equipment. Background Technology

[0002] In electrochemical energy storage devices, especially in the field of power battery packs, efficient thermal management is crucial for ensuring battery performance and safety. Related technologies often employ adhesive bonding to fix thermal management components to the surface of the battery module to achieve heat exchange. In another approach, a heating film and a direct cooling plate are sequentially stacked and bonded to the bottom of the battery module using a continuous thermally conductive adhesive layer. The heating film provides rapid heating, while the direct cooling plate achieves efficient heat dissipation.

[0003] However, in the aforementioned scheme of fixing the thermal management component through a continuous adhesive interface, the adhesive layer simultaneously performs the dual functions of mechanical fixation and heat conduction. Due to the inherent thermal resistance characteristics of the adhesive material, its large-area continuous coverage will form a uniform thermal resistance layer between the thermal management component and the battery cell, restricting further improvement in heat exchange efficiency. Adjusting the material or thickness of the adhesive layer to improve heat conduction may affect its mechanical strength and long-term reliability. Therefore, within a single continuous adhesive interface, the mechanical fixation function and the heat conduction function are mutually restrictive, making it difficult to achieve synergistic optimization. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide a battery pack and electrical device to improve the problem that it is difficult to optimize the bonding reliability and thermal management efficiency in a coordinated manner when fixing thermal management components through continuous bonding interfaces.

[0005] In a first aspect, embodiments of this application provide a battery pack having a height orientation and comprising: The battery module includes a first surface and a second surface disposed opposite to each other along the height direction; A first adhesive layer is disposed on the first surface; A second adhesive layer is disposed on the second surface; A cold plate is disposed on the first surface through the first adhesive layer; A heating film is disposed on the second surface via the second adhesive layer.

[0006] Optionally, the battery module includes multiple individual cells, and the multiple individual cells are arranged in an array. Along the height direction, each individual cell includes a first sub-surface and a second sub-surface disposed opposite to each other. The multiple first sub-surfaces constitute the first surface, and the multiple second sub-surfaces constitute the second surface. Each of the first sub-surfaces has a plurality of first through holes; and / or each of the second sub-surfaces has a plurality of second through holes.

[0007] Optionally, the first adhesive layer covers a portion of the area of ​​the first surface and fills a plurality of the first through-holes; and / or, The sum of the areas of the plurality of first through holes opened on each of the first sub-surfaces is defined as S1, and the area of ​​the first sub-surface is defined as S2, satisfying: 1 / 3≤S1 / S2≤1 / 2.

[0008] Optionally, the battery pack further includes a pressure plate and a third adhesive layer, wherein the pressure plate is disposed on the side of the heating film away from the second surface via the third adhesive layer along the height direction.

[0009] Optionally, the area of ​​the pressure plate is defined as Q1, and the sum of the areas of the second surfaces of all the battery modules is defined as Q2, satisfying: 80%≤Q1 / Q2≤90%.

[0010] Optionally, the heating film 14 has a plurality of third through holes 141, and the third adhesive layer covers the heating film and fills the plurality of third through holes.

[0011] Optionally, the sum of the areas of the plurality of third through holes is defined as S3, and the area of ​​the heating film is defined as S4, satisfying: 1 / 4 ≤ S3 / S4 ≤ 1 / 3; and / or, The sum of the areas of the plurality of second through holes opened on each of the second sub-surfaces is defined as S5, and the area of ​​the second sub-surface is defined as S6, satisfying: 1 / 10≤S4 / S6≤1 / 8.

[0012] Optionally, the single cell has a length direction perpendicular to the height direction, and the first sub-surface includes a first adhesive region and two first non-adhesive regions, with the first adhesive region located between the two first non-adhesive regions along the length direction; Wherein, the length of each of the first non-adhesive regions in the length direction is a1, and the length of the first adhesive region in the length direction is L1, satisfying: 1 / 30≤a1 / L1≤1 / 20.

[0013] Optionally, the single cell has a length direction perpendicular to the height direction, and the second sub-surface includes a second adhesive region and two second non-adhesive regions, with the second adhesive region located between the two second non-adhesive regions along the length direction; Wherein, the length of each of the second non-adhesive regions in the length direction is a2, and the length of the second adhesive region in the length direction is L2, satisfying: 1 / 30 ≤ a2 / L2 ≤ 1 / 20; and / or, Along the length direction, the minimum vertical distance c between the second through hole and the second non-adhesive area satisfies: c > 5 mm.

[0014] Secondly, embodiments of this application provide an electrical appliance, including: Electricity-consuming entities; The battery pack as described in the first aspect is electrically connected to the power-consuming body.

[0015] The beneficial effects of the embodiments of this application are as follows: The embodiments of this application provide a battery pack, which constructs an integrated bonding and heat conduction interface between the battery module and the cold plate and the heating film by setting a first adhesive layer on the first surface to fix the cold plate and a second adhesive layer on the second surface to fix the heating film. This not only ensures the necessary mechanical connection strength between the battery module and the cold plate and heating film, but also provides an effective heat transfer path for the cooling and heating of the battery through the adhesive layer, disperses interface stress, and optimizes thermal management efficiency, thereby synergistically improving the structural reliability and thermal management performance of the battery pack. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a battery pack provided in some embodiments of this application.

[0017] Figure 2 for Figure 1 An explosion diagram.

[0018] Figure 3 for Figure 1 The diagram shows a top view of the battery pack behind the hidden pressure plate and the third adhesive layer.

[0019] Figure 4 for Figure 1 The diagram shows a single battery cell with its structure inverted.

[0020] Figure 5 for Figure 4 The diagram shows a top view of a single battery cell.

[0021] Figure 6 for Figure 1 The diagram shows a single battery cell with its orientation upright.

[0022] Figure 7 for Figure 6 The diagram shows a top view of a single battery cell.

[0023] Explanation of reference numerals in the attached figures: 1. Battery pack; 11. Battery module; 111. Single cell; 1111. First sub-surface; 1111a. First adhesive area; 1111b. First non-adhesive area; 1112. Second sub-surface; 1112a. Second adhesive area; 1112b. Second non-adhesive area; 1113. First through hole; 1114. Second through hole; 112. First surface; 113. Second surface; 12. First adhesive layer; 13. Cold plate; 14. Heating film; 141. Third through hole; 15. Second adhesive layer; 16. Third adhesive layer; 17. Housing; 171. Receiving cavity; 18. Pressure plate; X represents the length direction; Z represents the height direction. Detailed Implementation

[0024] 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, and 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.

[0025] Please see also Figure 1 and Figure 2 This disclosure provides a battery pack 1. The battery pack 1 has an overall cuboid structure with a defined height direction Z. The battery pack 1 includes a battery module 11, a first adhesive layer 12, a second adhesive layer 15, a cold plate 13, and a heating film 14. The battery module 11 includes a first surface 112 and a second surface 113 disposed opposite to each other along the height direction Z. The first adhesive layer 12 is disposed on the first surface 112. The second adhesive layer 15 is disposed on the second surface 113. The cold plate 13 is disposed on the first surface 112 through the first adhesive layer 12. The heating film 14 is disposed on the second surface 113 through the second adhesive layer 15. In this embodiment, the first surface 112 and the second surface 113 disposed opposite to each other along the height direction Z are the bottom and top surfaces of the battery module 11.

[0026] The technical solution provided in this application constructs a bidirectional independent thermal management architecture for the battery pack 1 in the height direction Z. The cold plate 13 is responsible for actively cooling the battery module 11, and its internal flow channels allow the cooling medium to flow and remove heat. The heating film 14 is responsible for actively heating the battery module 11 in low-temperature environments. The first adhesive layer 12 and the second adhesive layer 15 simultaneously perform the dual functions of mechanical fixation and heat conduction. This solution spatially separates the cooling and heating functions, avoiding functional interference, and utilizes the first adhesive layer 12 and the second adhesive layer 15 to achieve a compact and efficient integrated connection, thereby synergistically improving the thermal management efficiency and structural reliability of the battery pack 1.

[0027] In a further embodiment, please refer to Figures 2 to 4 The battery module 11 includes multiple individual battery cells 111. These individual battery cells 111 are arranged in an array. Along the height direction Z, each individual battery cell 111 includes a first sub-surface 1111 and a second sub-surface 1112 disposed opposite to each other. The first sub-surfaces 1111 of all individual battery cells 111 together constitute the aforementioned first surface 112, and the second sub-surfaces 1112 of all individual battery cells 111 together constitute the aforementioned second surface 113. Each first sub-surface 1111 has multiple first through holes 1113. The multiple first through holes 1113 penetrate the insulating layer outside the battery cell, such as the blue film.

[0028] In some embodiments, see Figure 6 Each of the second sub-surfaces 1112 has multiple second through holes 1114. The multiple second through holes 1114 also penetrate the outer insulating layer of the cell, such as the blue film.

[0029] It should be noted that in this embodiment, the first sub-surface 1111 is the bottom surface of the single cell 111, and the second sub-surface 1112 is the top surface of the single cell 111.

[0030] For the first sub-surface 1111, the presence of the first through-hole 1113 allows the subsequently coated first adhesive layer 12 to partially fill the hole, forming a mechanical interlock with the housing 17 of the individual cell 111, thereby enhancing the shear and peel resistance between the cold plate 13 and the individual cell 111. Furthermore, by utilizing the first through-hole 1113 and the first adhesive layer 12, a more direct channel for heat transfer from the individual cell 111 to the cold plate 13 can be provided, reducing interfacial thermal resistance.

[0031] For the second sub-surface 1112, the presence of the second through-hole 1114 allows the subsequently coated third adhesive layer 16 to partially fill the hole, forming a mechanical interlock with the housing 17 of the individual cell 111, thus enhancing the shear and peel resistance between the heating film 14 and the individual cell 111. Furthermore, by utilizing the second through-hole 1114 and the third adhesive layer 16, a more direct channel for heat transfer from the heating film 14 to the individual cell 111 can be provided, reducing interfacial thermal resistance.

[0032] It should be noted that the third adhesive layer 16 will be explained in detail later. The first adhesive layer 12 can be made of thermally conductive structural adhesive, and the third adhesive layer 16 can also be made of thermally conductive structural adhesive. The second adhesive layer 15 is made of double-sided adhesive, which is shaped to follow the heating film 14 and avoids the second through-hole 1114. This ensures that the third adhesive layer 16 can fill the second through-hole 1114 while also enhancing the adhesion between the heating film 14 and the individual battery cell 111.

[0033] Further, please see Figure 2 , Figure 4 as well as Figure 5 The first adhesive layer 12 covers a portion of the area of ​​the first surface 112 and fills multiple first through holes 1113, transforming the bonding interface from planar contact to three-dimensional interlocking, further strengthening the mechanical and thermal connections. To ensure a balance between the opening effect and the structural strength of the individual cell 111, the opening area is limited. The sum of the areas of the multiple first through holes 1113 on each first sub-surface 1111 is defined as S1, and the area of ​​the first sub-surface 1111 is defined as S2. S1 and S2 satisfy: 1 / 3 ≤ S1 / S2 ≤ 1 / 2. For example, the ratio of S1 to S2 can be 1 / 3, 2 / 5, or 1 / 2, etc. When the ratio is 1 / 3, it provides an effective area for enhanced bonding and heat dissipation while ensuring the structural integrity of the bottom of the individual cell 111. When the ratio is 1 / 2, the mechanical interlocking and thermal conduction optimization benefits brought by the opening can be maximized. A ratio of approximately 2 / 5 is a common preferred intermediate value. If the ratio is too low, the improvement effect will be limited; if the ratio is too high, it may affect the mechanical reliability of the bottom insulation layer of the battery cell.

[0034] In some embodiments, see Figure 2 , Figure 4 as well as Figure 5 The battery pack 1 also includes a pressure plate 18 and a third adhesive layer 16. Along the height direction Z, the pressure plate 18 is disposed on the side of the heating film 14 away from the second surface 113 via the third adhesive layer 16. The introduction of the pressure plate 18 provides additional rigid support to the top of the battery module 11, enhancing the structural rigidity and integrity of the entire module in the height direction Z, effectively coping with vibrations and impacts during vehicle operation. Furthermore, the pressure plate 18 also limits the overall mode of the battery pack 1 to the range of 35Hz to 50Hz, preventing resonance between the battery pack 1 assembled in the vehicle and the road surface over which the vehicle travels; the road surface mode is generally less than 30Hz.

[0035] Further, please see Figure 2 and Figure 3To ensure that the pressure plate 18 provides effective support without excessively hindering the heat radiation of the heating film 14, the dimensions of the pressure plate 18 are limited. The area of ​​the pressure plate 18 is defined as Q1, and the sum of the areas of the second surfaces 113 of all battery modules 11 within the battery pack 1 is defined as Q2. Q1 and Q2 satisfy: 80% ≤ Q1 / Q2 ≤ 90%. For example, the value of Q1 / Q2 can be 80%, 85%, or 90%. When the ratio is 80%, the pressure plate 18 covers the main support area while leaving ample space at the edges, which is beneficial for heat dissipation. When the ratio is 90%, the pressure plate 18 provides maximum coverage and support, suitable for scenarios requiring high rigidity. When the ratio is 85%, a good balance is achieved between support and thermal management. In addition, by limiting the area of ​​the pressure plate 18 to be smaller than the second surface 113, when the pressure plate 18 is fixed by the third adhesive layer 16, the third adhesive layer 16 will not completely cover the second surface 113, and the area of ​​the third adhesive layer 16 can also be smaller than the second surface 113, so as to prevent the third adhesive layer 16 from flowing into the interior of the individual cell 111 through the weld of the individual cell 111.

[0036] Furthermore, please see Figure 2 and Figure 3 The heating film 14 has multiple third through holes 141 on its body. A third adhesive layer 16 covers the heating film 14 and fills the multiple third through holes 141. This means that the third adhesive layer 16 is not only present between the heating film 14 and the pressure plate 18, but flows downward and fills the hollow areas of the heating film 14, i.e., the third through holes 141. It then contacts the surface of the individual battery cell 111 through the third through holes 141, forming a continuous colloidal structure that extends from the pressure plate 18 through the heating film 14 and flows to the individual battery cell 111, adhering to the individual battery cell 111. This continuous colloidal structure can generate a large three-dimensional mechanical interlock, firmly bonding the pressure plate 18, the heating film 14, and the top of the individual battery cell 111 into one unit, which is beneficial to improving the integration and overall rigidity of the top structure of the individual battery cell 111. In addition, by using a third adhesive layer 16 to fill the third through hole 141, the cavity inside the third through hole 141 is completely eliminated, the risk of condensation is eliminated, and the insulation safety of the individual cell 111 is ensured.

[0037] In some embodiments, the sum of the areas of the plurality of third through holes 141 is defined as S3, and the area of ​​the heating film 14 is defined as S4. S3 and S4 satisfy: 1 / 4 ≤ S3 / S4 ≤ 1 / 3. Exemplarily, S3 / S4 can be 1 / 4, 5 / 12, or 1 / 3. By limiting the ratio of S3 to S4, it is beneficial to ensure that the heating film 14 has sufficient area of ​​third through holes 141 to facilitate the penetration and heat flow of the third adhesive layer 16, while retaining the main heating circuit and the necessary mechanical strength.

[0038] In some embodiments, the sum of the areas of the plurality of second through holes 1114 opened on each second sub-surface 1112 is defined as S5, and the area of ​​the second sub-surface 1112 is S6. S5 and S6 satisfy: 1 / 10 ≤ S4 / S6 ≤ 1 / 8. For example, the ratio of S5 to S6 can be 1 / 10, 1 / 9, or 1 / 8. This ratio range allows the top of the cell to achieve adhesive enhancement benefits through appropriate openings without excessively weakening its own structure.

[0039] In some embodiments, see Figure 4 and Figure 5 The single cell 111 has a length direction X perpendicular to the height direction Z. On the first sub-surface 1111, it includes a first adhesive region 1111a and two first non-adhesive regions 1111b. Along the length direction X, the first adhesive region 1111a is located between the two first non-adhesive regions 1111b. A first adhesive layer 12 is only disposed within the first adhesive region 1111a, while the first non-adhesive regions 1111b remain unadhesive, forming an edge isolation buffer zone. The length of each first non-adhesive region 1111b in the length direction X is defined as a1, and the length of the first adhesive region 1111a in the length direction X is defined as L1. a1 and L1 satisfy: 1 / 30 ≤ a1 / L1 ≤ 1 / 20. For example, for a battery cell with an adhesion region length L1 of 450 mm, the length of a1 can be between 15 mm and 22.5 mm, specifically 15 mm, 18 mm, or 22.5 mm. This creates a free area between the end of the individual battery cell 111 (typically the weld area) and the rigid bonding area, allowing vibration stress to be released and effectively reducing the risk of cracking or leakage at the end due to stress concentration. Furthermore, because the first adhesive layer 12 is only disposed in the first adhesion region 1111a and not in the first non-adhesion region 1111b, it also prevents the first adhesive layer 12 from flowing into the individual battery cell 111 through the weld seam.

[0040] In some embodiments, see Figure 6 and Figure 7The second sub-surface 1112 includes a second adhesive region 1112a and two second non-adhesive regions 1112b. Along the length direction X, the second adhesive region 1112a is located between the two second non-adhesive regions 1112b. The second adhesive layer 15 and the third adhesive layer 16 are both confined within the second adhesive region 1112a. The length of each second non-adhesive region 1112b in the length direction X is defined as a2, and the length of the second adhesive region 1112a in the length direction X is defined as L2. a2 and L2 satisfy: 1 / 30 ≤ a2 / L2 ≤ 1 / 20. For example, for a battery cell with an adhesion region length L2 of 450 mm, the length of a2 can be between 15 mm and 22.5 mm, specifically 15 mm, 18 mm, or 22.5 mm. This allows for a free area between the end of the individual battery cell 111 (typically the weld area) and the rigid bonding area, where vibration stress is released, effectively reducing the risk of cracking or leakage at the end due to stress concentration. Furthermore, because the third adhesive layer 16 is only disposed in the second adhesion region 1112a and not in the second non-adhesion region 1112b, it also prevents the third adhesive layer 16 from flowing into the individual battery cell 111 through the weld seam.

[0041] Furthermore, to ensure the bonding reliability at the top second through-hole 1114 and to prevent the opening from being too close to the non-adhesive edge, the minimum vertical distance c between the second through-hole 1114 and the second non-adhesive area 1112b along the length direction X is specified to satisfy: c > 5 mm. For example, this distance c can be 6 mm, 8 mm, or 10 mm. This minimum distance ensures that there is sufficient material at the edge of the through-hole to bear the adhesive force, preventing edge adhesive failure, and also allows for allowance for the third adhesive layer 16 to overflow towards the second non-adhesive area 1112b due to the pressure of the pressure plate 18, preventing the third adhesive layer 16 from overflowing into the second non-adhesive area 1112b.

[0042] It should be noted that the outline shape of the first through hole 1113, the second through hole 1114, and the third through hole 141 involved in the foregoing embodiments is preferably designed with a rounded transition, such as a circle, an ellipse, or a rounded rectangle. This smooth transition can avoid the generation of sharp stress concentration points on the individual battery cell 111 or the heating film 14, thereby improving the durability of the material during long-term use and preventing tearing from the corners of the holes.

[0043] In a specific implementation, a preferred form of the single battery cell 111 is a blade-shaped cell, whose length (X) dimension is significantly larger than its width and height (Z) dimensions. For example, its length can be between 300 mm and 600 mm, and its width between 12 mm and 20 mm. This flattened configuration allows the first sub-surface 1111 and the second sub-surface 1112 of the single battery cell 111 to have a large area, making it very suitable for using the aforementioned discontinuous bonding interface to improve the overall thermal management efficiency and mechanical stability of the battery pack 1.

[0044] It should also be noted that the first adhesive layer 12 preferably uses a thermally conductive structural adhesive with high thermal conductivity to maximize cooling heat transfer efficiency. The second adhesive layer 15 can use double-sided adhesive in the basic connection, while in the structure requiring integration with the pressure plate 18, the third adhesive layer 16, which achieves the through-fill function, needs to use a structural adhesive with good flowability and high curing strength. The application of both the first adhesive layer 12 and the third adhesive layer 16 must ensure complete filling of the target through-holes. For example, the first adhesive layer 12 should fill the first through-hole 1113, and the third adhesive layer 16 should fill the second through-hole 1114, achieving a gapless sealing and ensuring the expected mechanical interlocking and insulation protection effects are achieved.

[0045] In some embodiments, see Figure 1 and Figure 2 The battery pack 1 also includes a housing 17, which has a receiving cavity 171. Along the height direction Z, the cold plate 13, the first adhesive layer 12, the battery module 11, the second adhesive layer 15, the heating film 14, the third adhesive layer 16 and the pressure plate 18 are sequentially stacked and housed in the receiving cavity 171.

[0046] This application also discloses an electrical device (not shown in the figure), which can be an electric vehicle or other electrical device that requires the battery pack 1. In this embodiment, the electrical device is described as an electric vehicle, which includes an electrical component, such as the vehicle body, motor, and electronic control system, and the battery pack 1 as described above. The battery pack 1 supplies power to the electrical component through an electrical interface. Optimizing the battery pack 1 benefits the entire vehicle, such as high thermal management efficiency and adhesion stability, which can improve vehicle driving safety and reduce vehicle energy consumption, thus extending the vehicle's range.

[0047] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery pack, characterized in that, Having a height orientation and including: The battery module includes a first surface and a second surface disposed opposite to each other along the height direction; A first adhesive layer is disposed on the first surface; A second adhesive layer is disposed on the second surface; A cold plate is disposed on the first surface through the first adhesive layer; A heating film is disposed on the second surface via the second adhesive layer.

2. The battery pack according to claim 1, characterized in that, The battery module includes multiple individual cells, and the multiple individual cells are arranged in an array. Along the height direction, each individual cell includes a first sub-surface and a second sub-surface that are disposed opposite to each other. The multiple first sub-surfaces constitute the first surface, and the multiple second sub-surfaces constitute the second surface. Each of the first sub-surfaces has a plurality of first through holes; and / or each of the second sub-surfaces has a plurality of second through holes.

3. The battery pack according to claim 2, characterized in that, The first adhesive layer covers a portion of the area of ​​the first surface and fills the plurality of the first through holes; and / or, The sum of the areas of the plurality of first through holes opened on each of the first sub-surfaces is defined as S1, and the area of ​​the first sub-surface is defined as S2, satisfying: 1 / 3≤S1 / S2≤1 / 2.

4. The battery pack according to claim 2, characterized in that, The battery pack also includes a pressure plate and a third adhesive layer. Along the height direction, the pressure plate is disposed on the side of the heating film away from the second surface via the third adhesive layer.

5. The battery pack according to claim 4, characterized in that, The area of ​​the pressure plate is defined as Q1, and the sum of the areas of the second surfaces of all the battery modules is defined as Q2, satisfying: 80%≤Q1 / Q2≤90%.

6. The battery pack according to claim 5, characterized in that, The heating film has multiple third through holes, and the third adhesive layer covers the heating film and fills the multiple third through holes.

7. The battery pack according to claim 6, characterized in that, The sum of the areas of the plurality of third through holes is defined as S3, and the area of ​​the heating film is defined as S4, satisfying: 1 / 4 ≤ S3 / S4 ≤ 1 / 3; and / or, The sum of the areas of the plurality of second through holes opened on each of the second sub-surfaces is defined as S5, and the area of ​​the second sub-surface is defined as S6, satisfying: 1 / 10≤S4 / S6≤1 / 8.

8. The battery pack according to any one of claims 2 to 7, characterized in that, The single cell has a length direction perpendicular to the height direction, and the first sub-surface includes a first adhesive region and two first non-adhesive regions. Along the length direction, the first adhesive region is located between the two first non-adhesive regions. Wherein, the length of each of the first non-adhesive regions in the length direction is a1, and the length of the first adhesive region in the length direction is L1, satisfying: 1 / 30≤a1 / L1≤1 / 20.

9. The battery pack according to any one of claims 2 to 7, characterized in that, The single cell has a length direction perpendicular to the height direction, and the second sub-surface includes a second adhesive region and two second non-adhesive regions. Along the length direction, the second adhesive region is located between the two second non-adhesive regions. Wherein, the length of each of the second non-adhesive regions in the length direction is a2, and the length of the second adhesive region in the length direction is L2, satisfying: 1 / 30 ≤ a2 / L2 ≤ 1 / 20; and / or, Along the length direction, the minimum vertical distance c between the second through hole and the second non-adhesive area satisfies: c > 5 mm.

10. An electrical appliance, characterized in that, include: Electricity-consuming entities; The battery pack as described in any one of claims 1 to 9 is electrically connected to the power-consuming body.

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