Battery pack and electric device

Abstract

This application provides a battery pack and an electrical device, relating to the field of battery technology. The battery pack includes a housing, a battery module, and at least one set of heat exchange components. The housing includes a support plate; the battery module is disposed on the support plate and has a first surface; at least one set of heat exchange components is disposed between the support plate and the battery module. The heat exchange components are connected to the support plate by a first adhesive layer, and to the first surface of the battery module by a second adhesive layer. The heat exchange components include multiple spaced heat exchange tubes connected by bends. Along the direction perpendicular to the support plate, the thickness of the first adhesive layer is d1 mm, the thickness of the second adhesive layer is d2 mm, and d1 mm + d2 mm = K mm. Along the direction perpendicular to the support plate, the ratio of the sum of the wall thicknesses of the heat exchange tubes to the total thickness of the heat exchange tubes is T, satisfying: 0.94 ≤ K / T ≤ 39.2. This improves the battery heat exchange efficiency and ensures the structural strength of the heat exchange tubes.

Description

Technical Field

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

[0002] During the charge-discharge cycle of a battery pack, heat is inevitably generated, necessitating a heat exchange device to regulate battery temperature and prevent thermal runaway in overheated environments. In related technologies, heat exchange devices can utilize heat exchange bends, which offer high forming efficiency, simple manufacturing processes, and improved production efficiency and yield, while also enhancing the internal space utilization of the battery pack. However, as the battery pack is used, the heat exchange bends may become less effective at transferring heat to the battery, or even break, compromising the battery pack's safety. Summary of the Invention

[0003] The purpose of this application is to provide a battery pack and an electrical device to solve the technical problem of poor heat exchange effect of batteries in existing battery packs.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, this application provides a battery pack, including a housing, a battery module, and at least one set of heat exchange components. The housing has a receiving space and includes a support plate. The battery module includes at least two individual batteries, which are received within the receiving space. The battery module is disposed on the support plate and has a first surface. At least one set of heat exchange components is disposed between the support plate and the battery module and is heat-exchange connected to the first surface of the battery module. The heat exchange components are connected to the support plate through a first adhesive layer and to the first surface of the battery module through a second adhesive layer. The heat exchange components include a plurality of spaced heat exchange tubes, which are connected to each other through bends. The heat exchange tubes have heat exchange channels inside that allow heat exchange medium to pass through. The thickness of the first adhesive layer is d1 mm and the thickness of the second adhesive layer is d2 mm along the direction perpendicular to the support plate, where d1 mm + d2 mm = K mm. The ratio of the sum of the wall thicknesses of the heat exchange tubes to the total thickness of the heat exchange tubes along the direction perpendicular to the support plate is T, which satisfies: 0.94 ≤ K / T ≤ 39.2.

[0005] The above technical solution has at least the following beneficial technical effects: In the battery pack provided in this application embodiment, heat exchange tubes are set and connected by bending sections to achieve heat exchange connection with the first surface of the battery module. This ensures the heat exchange efficiency between the heat exchange tubes and the battery while improving the overall space utilization in the height direction of the battery pack, thus reducing the overall amount of adhesive layer used. Simultaneously, the relationship between the thickness of the first adhesive layer (d1 mm), the thickness of the second adhesive layer (d2 mm), and the ratio T of the total wall thickness of the heat exchange tubes to the total thickness of the heat exchange tubes is comprehensively controlled, satisfying: 0.94 ≤ K / T ≤ 39.2, K mm = d1 mm + d2 mm. When K / T is less than 0.94, the connection strength between the individual battery and the casing is weak, and the risk of overall battery pack structural failure is high. When K / T is greater than 39.2, it will lead to excessive deformation of the heat exchange tubes, resulting in excessive flow resistance of the heat exchange medium in the heat exchange channel, poor heat exchange efficiency of the individual battery, and increased charging time. Therefore, d1, d2 and T need to be considered comprehensively, and K / T needs to be limited to the range of 0.94~39.2 to ensure that the heat exchange tube has sufficient structural strength, improve the heat exchange efficiency of individual cells, and ensure the heat dissipation performance of the battery pack while also ensuring the overall structural strength of the battery pack.

[0006] Secondly, this application provides an electrical device including the battery pack described in the second aspect. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art 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.

[0008] Figure 1 This is a three-dimensional structural diagram of the battery pack provided in the embodiments of this application.

[0009] Figure 2 This is a schematic diagram of the exploded disintegration structure of the battery pack provided in the embodiments of this application.

[0010] Figure 3 This is a top view of the battery pack provided in an embodiment of this application.

[0011] Figure 4 yes Figure 3 AA section diagram.

[0012] Figure 5 yes Figure 4 Enlarged view of point A in the image.

[0013] Figure 6 This is a schematic diagram of the longitudinal section structure of the heat exchange tube provided in the embodiment of this application.

[0014] Figure 7 This is a schematic diagram of the longitudinal section structure of a heat exchange tube provided in another embodiment of this application.

[0015] Figure 8 This is a schematic diagram of the arrangement of battery modules and heat exchange components in a battery pack provided in an embodiment of this application.

[0016] Figure 9 This is a schematic diagram of the structure of the heat exchange component in the battery pack provided in the embodiments of this application.

[0017] In the diagram: 1-Battery module; 2-Heat exchange assembly; 3-Box; 10-First surface; 21-Heat exchange tube; 22-Bent section; 23-Inlet; 24-Outlet; 25-Current collector; 31-Support plate; 32-Side plate; 111-Single cell; 211-Second adhesive layer; 212-First adhesive layer; 213-Third adhesive layer; 214-First heat exchange tube; 215-Second heat exchange tube; 311-Groove; 312-Protrusion; 2110-Straight section; 2111-Arc section; 2112-Heat exchange channel. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0019] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0020] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0022] The applicant's research found that the main reason for the reduced battery cooling efficiency caused by heat exchanger tube structural rupture is that, compared to traditional vapor chamber liquid cooling plates, the heat exchanger tube has a smaller overall contact area with the battery module, making it prone to stress concentration. Existing battery modules are typically bonded to the support plate of the casing with structural adhesive. During charging and discharging, the battery module expands, squeezing the structural adhesive. The cured adhesive has a high hardness, causing the upper wall of the heat exchanger tube to bear significant compressive force. Since the heat exchanger tube has a reduced projected area at the bottom of the battery module compared to traditional vapor chamber liquid cooling plates, i.e., a smaller heat exchange area, the pressure generated by the same compressive force is greater. Simultaneously, the lower wall of the heat exchanger tube also needs to withstand greater bottom impact. Therefore, the combined upward and downward compressive force causes the heat exchanger tube to deform towards the center, reducing the cross-sectional area of ​​the internal heat exchange channel and increasing the overall flow resistance of the heat exchange medium. This weakens the heat dissipation effect on individual batteries, increasing the risk of heat exchanger tube breakage during prolonged use. In particular, the structural adhesive can fill the spaces between heat exchanger tubes, making it difficult for the heat exchanger tube to deform and expand to the sides, further exacerbating the deformation.

[0023] Based on the above considerations, in order to solve the technical problems of easy deformation and poor heat exchange efficiency of heat exchange devices in the prior art, this application provides a battery pack and an electrical device.

[0024] The battery pack of this application is applicable to electrical devices that use batteries as a power source. The electrical devices disclosed in the embodiments of this application can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, energy storage devices, amusement equipment, elevators, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc.

[0025] This application describes an electrical device using a vehicle as an example. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery pack is installed inside the vehicle, and the battery pack can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller controls the battery to supply power to the motor, for example, to meet the vehicle's power needs during starting, navigation, and driving. The battery pack can not only serve as the vehicle's operating power source but also as its driving power source, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle.

[0026] The technical solution of this application will now be described in detail with reference to the accompanying drawings.

[0027] Please refer to the above as well. Figures 1 to 5 This application provides a battery pack, including a housing 3, a battery module 1, and at least one set of heat exchange components 2. The housing 3 has a receiving space and includes a support plate 31. The battery module 1 includes at least two individual batteries 111, and the battery module 1 is housed within the receiving space. The battery module 1 is disposed on the support plate 31 and has a first surface 10. At least one heat exchange assembly 2 is disposed between the support plate 31 and the battery module 1, and is heat-exchange connected to the first surface 10 of the battery module 1. The heat exchange assembly 2 is connected to the support plate 31 through a first adhesive layer 212, and the heat exchange assembly 2 is connected to the first surface 10 of the battery module 1 through a second adhesive layer 211. The heat exchange assembly 2 includes a plurality of spaced heat exchange tubes 21, which are connected by a bend section 22. The heat exchange tubes 21 are provided with heat exchange channels 2112 that allow the heat exchange medium to pass through. The thickness of the first adhesive layer 212 is d1 mm and the thickness of the second adhesive layer 211 is d2 mm along the direction perpendicular to the support plate 31. d1 mm + d2 mm = K mm. The ratio of the sum of the wall thicknesses of the heat exchange tubes 21 to the total thickness of the heat exchange tubes 21 along the direction perpendicular to the support plate 31 is T, which satisfies: 0.94 ≤ K / T ≤ 39.2. For example, K / T can be 0.94, 1.20, 1.23, 1.38, 1.91, 2.09, 2.38, 3.12, 4.00, 6.00, 7.56, 10.33, 16.23, 22.8, 28.00, 34.5, 39.2, etc., or any value between any two adjacent values ​​mentioned above.

[0028] It should be noted that the enclosure 3 refers to a closed or semi-closed structural component made of materials such as metal and plastic. It serves as the physical carrier for the battery module 1, BMS, heat exchange assembly 2, and electrical connection components. It provides installation space for these components and, through a reasonable structural design, secures them within the enclosure 3, ensuring their relatively stable position during battery pack operation and preventing damage or loosening due to vibration, impact, or other factors. The design and manufacture of the enclosure 3 must meet the safety, reliability, and functionality requirements of the battery pack under different usage scenarios. The enclosure 3 generally consists of an upper enclosure and a lower enclosure. The lower enclosure 3 includes a support plate 31 and four side plates 32. The support plate 31 can be the base plate of the lower enclosure 3. The four side plates 32 are arranged around the outer circumferential edge of the support plate 31 and are integrally formed with the support plate 31, or they can be separately connected to the support plate 31. The upper enclosure is positioned opposite the support plate 31 so that the upper and lower enclosures together form a space for accommodating the battery module 1. The enclosure 3 can be cast from materials such as steel plate or aluminum alloy, or it can be made of high-strength materials, such as glass fiber reinforced composite materials or carbon fiber reinforced composite materials. The shape of the enclosure 3 can be cylindrical, cuboid, cube, etc.

[0029] The support plate 31 is the main load-bearing component of the battery pack, typically referring to a structural component installed at the bottom of the battery pack, used to support and fix the battery modules 1, battery management system, and heat exchange components 2 inside the battery pack. The support plate 31 is located at the bottom of the side plate 32 and can be fixed to the bottom of the side plate 32 by methods such as welding, riveting, or screwing. The support plate 31 can be made of various materials, such as high-strength materials like aluminum alloy, steel, and stainless steel. The support plate 31 can be a rectangular, circular, or polygonal plate structure, with no specific limitation; its size is determined by the number of individual batteries contained in the battery pack and the size of each individual battery.

[0030] The heat exchange medium flowing in the heat exchange channel 2112 can be gas (air), liquid (such as water, alcohol, ethylene glycol / propylene glycol solution, refrigerant, oil, etc.) or solid (such as thermally conductive adhesive, thermally conductive solder paste, etc.).

[0031] The battery module 1 is mounted on the support plate 31, which can be understood as the battery module 1 being fixedly connected above the support plate 31, and the support plate 31 providing support for the battery module 1. The multiple heat exchange tubes 21 are connected by a bend 22, which can be understood as the multiple heat exchange tubes 21 forming a heat exchange bend through the bend 22. The bend 22 can be understood as a component that connects two heat exchange tubes 21, causing the heat exchange medium within the heat exchange tubes 21 to change direction.

[0032] It should be noted that, along the direction perpendicular to the support plate 31, the total wall thickness of the heat exchange tube 21 can be obtained by taking a cross-section of the heat exchange tube 21 along a plane perpendicular to its extension direction, and adding the thickness of the upper wall of the heat exchange tube 21 facing the battery module 1 to the thickness of the lower wall facing the support plate 31. The method for measuring the upper or lower wall thickness of the heat exchange tube 21 can be as follows: cut the heat exchange tube 21 along a plane perpendicular to its extension direction, and measure the upper or lower wall thickness at five evenly spaced points along the cut.

[0033] It is understandable that the total thickness of the heat exchange tube 21 includes the total wall thickness of the heat exchange tube 21 and the height of the heat exchange flow 2112. That is, the heat exchange tube 21 is cross-sectioned along the plane perpendicular to the extension direction of the heat exchange tube 21. The distance between the upper wall surface of the heat exchange tube 21 near the battery module 1 and the lower wall surface near the support plate 31 is the total thickness of the heat exchange tube 21.

[0034] In the technical solution of this application embodiment, a heat exchange tube 21 is set and connected to the first surface 10 of the battery module 1 through a bending section 22 to achieve heat exchange connection. This ensures the heat exchange efficiency between the heat exchange tube 21 and the individual battery cell 111, while improving the space utilization rate in the overall height direction of the battery pack and reducing the overall amount of adhesive layer used. Simultaneously, the relationship between the thickness d1 mm of the first adhesive layer 212, the thickness d2 mm of the second adhesive layer 211, and the ratio T of the sum of the wall thicknesses of the heat exchange tube 21 to the total thickness of the heat exchange tube 21 is comprehensively controlled, satisfying: 0.94 ≤ K / T ≤ 39.2, K mm = d1 mm + d2 mm. When K / T is less than 0.94, the connection strength between the individual battery cell 111 and the housing 3 is weak, and the risk of overall battery pack structural failure is high. When K / T is greater than 39.2, it will cause large deformation of the heat exchange tube 21, resulting in excessive flow resistance of the heat exchange medium in the heat exchange channel 2112, poor battery heat exchange efficiency, and increased charging time. Therefore, d1, d2 and T need to be considered comprehensively, and K / T needs to be limited to the range of 0.94~39.2 to ensure that the heat exchange tube 21 has sufficient structural strength, improve the battery heat exchange efficiency, and ensure the heat dissipation performance of the battery pack while also ensuring the overall structural strength of the battery pack.

[0035] In some embodiments, the following condition is satisfied: 2.38 ≤ K / T ≤ 22.8. For example, K / T can be 2.38, 3.12, 4.00, 6.00, 7.56, 10.33, 16.23, 22.8, etc., or any value between any two adjacent values ​​mentioned above. This setting ensures suitable connection strength between the individual battery cell 111 and the housing 3, reduces the number of individual batteries 111 detaching from the battery pack, ensures the overall structural strength of the battery pack, and simultaneously ensures sufficient structural strength for the heat exchange tube 21, reducing the maximum deformation of the heat exchange tube 21 and improving the heat exchange effect.

[0036] In some embodiments, the following condition is satisfied: 0.6mm ≤ K mm ≤ 4.5mm. For example, K mm can be 0.6mm, 0.7mm, 0.8mm, 1.0mm, 1.3mm, 1.5mm, 1.8mm, 2.0mm, 2.4mm, 2.6mm, 2.8mm, 3.0mm, 3.3mm, 3.6mm, 3.8mm, 4.0mm, 4.2mm, 4.5mm, etc., or any value between any two adjacent values ​​mentioned above.

[0037] By controlling the sum of the thicknesses d1 mm of the first adhesive layer 212 and d2 mm of the second adhesive layer 211, Kmm, within the range of 0.6 mm to 4.5 mm, the heat exchange assembly 2 is made to have sufficient structural strength while ensuring sufficient structural strength of the battery pack, thereby improving the heat exchange efficiency of the battery and reducing the charging time. When Kmm < 0.6 mm, the sum of the thicknesses of the first adhesive layer 212 and the second adhesive layer 211 is too small, resulting in weak fixation between the individual battery cell 111 and the heat exchange tube 21, and between the heat exchange tube 21 and the support plate 31 of the housing 3. This increases the risk of the heat exchange tube 21 detaching from the individual battery cell 111 and the housing 3, leading to weaker connection strength between the individual battery cell 111 and the housing 3, and a greater risk of overall battery pack structural failure. When K mm > 4.5 mm, the sum of the thicknesses of the first adhesive layer 212 and the second adhesive layer 211 is too large. This results in an excessively long heat exchange path between the heat exchange tube 21 and the single cell 111, leading to poor heat exchange efficiency. Furthermore, to achieve the desired thickness of the first adhesive layer 212 and the second adhesive layer 211, greater force needs to be applied during assembly to compress the first adhesive layer 212 and the second adhesive layer 211, thereby compressing the heat exchange tube 21. This increases the tendency of the heat exchange tube 21 to be compressed, leading to greater deformation of the heat exchange tube 21. Consequently, the flow resistance of the heat exchange medium in the heat exchange channel becomes too large, resulting in poor battery heat exchange efficiency and increased charging time.

[0038] In some embodiments, K mm = d1 mm + d2 mm, where the thickness d1 mm of the first adhesive layer 212 satisfies: 0.1 mm ≤ d1 mm ≤ 1.5 mm. For example, d1 mm can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc., or any value between any two adjacent values ​​mentioned above.

[0039] By controlling the thickness of the first adhesive layer 212 within the range of 0.1mm to 1.5mm, the first adhesive layer 212 achieves sufficient bonding strength while preventing its excessive thickness from requiring greater force on the heat exchange tube 21 during assembly to reach the preferred thickness, thus reducing the probability of deformation of the heat exchange tube 21. When d1 mm < 0.1mm, the thickness of the first adhesive layer 212 is too small, resulting in weak bonding strength between the heat exchange tube 21 and the support plate 31, increasing the risk of detachment. When d1 mm > 1.5mm, the thickness of the first adhesive layer 212 is too large, requiring greater force on the heat exchange tube 21 during assembly to reach the preferred thickness, increasing the risk of deformation of the heat exchange tube 21.

[0040] In some embodiments, the thickness d2 mm of the second adhesive layer 211 satisfies: 0.5 mm ≤ d2 mm ≤ 3 mm. For example, d2 mm can be 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.3 mm, 2.6 mm, 2.7 mm, 2.8 mm, 3 mm, etc., or any value between any two adjacent values ​​mentioned above.

[0041] By controlling the thickness of the second adhesive layer 211 within the range of 0.5mm to 3mm, the second adhesive layer 211 achieves sufficient adhesive strength while increasing the heat exchange rate between the heat exchange tube 21 and the individual battery 111, thus reducing the probability of deformation of the heat exchange tube 21. When d2 mm < 0.5mm, the thickness of the second adhesive layer 211 is too small, resulting in weak adhesive strength between the heat exchange tube 21 and the individual battery 111, increasing the risk of detachment. When d2 mm > 3mm, the thickness of the second adhesive layer 211 is too large, increasing the heat exchange path between the heat exchange tube 21 and the individual battery 111, reducing the heat exchange rate. Furthermore, an excessively large thickness of the second adhesive layer 211 requires greater force to be applied to the heat exchange tube 21 during assembly to achieve the optimal thickness, increasing the risk of deformation of the heat exchange tube 21.

[0042] In some embodiments, the following condition is satisfied: 0.107 ≤ T ≤ 0.737. For example, T can be 0.107, 0.130, 0.143, 0.167, 0.203, 0.247, 0.290, 0.312, 0.362, 0.370, 0.400, 0.500, 0.577, 0.630, 0.640, 0.667, 0.679, 0.727, 0.737, etc., or any value between any two adjacent values ​​mentioned above. In some embodiments, the thickness of the upper or lower wall of the heat exchange tube 21, i.e., the thickness of one side of the heat exchange tube 21, is 0.3mm to 2mm. The height of the heat exchange channel 2112 is 1.5mm to 5mm.

[0043] By controlling the ratio T of the total wall thickness of heat exchange tubes 21 to their total thickness within the range of 0.107 to 0.737, the heat exchange tubes 21 are ensured to have sufficient structural strength while preventing the cross-sectional area of ​​the heat exchange channels 2112 within the heat exchange tubes 21 from becoming too small, thereby improving the battery's heat exchange efficiency and reducing charging time. When T < 0.107, the ratio of the total wall thickness of heat exchange tubes 21 to their total thickness is too small, resulting in greater deformation of the heat exchange tubes 21. This increases the flow resistance of the heat exchange medium within the heat exchange channels, leading to poorer battery heat exchange efficiency and longer charging time. When T > 0.737, the ratio of the total wall thickness of heat exchange tubes 21 to their total thickness is too large. This results in an excessively large wall thickness of the heat exchange tubes 21, causing the cross-sectional area of ​​the heat exchange channels 2112 within the heat exchange tubes 21 to become too small, increasing the flow resistance of the heat exchange medium and further reducing battery heat exchange efficiency.

[0044] In some embodiments, since the first adhesive layer 212 is disposed between the heat exchange assembly 2 and the support plate 31, it needs to withstand impact forces from the direction of the support plate 31 to a certain extent. Therefore, the elastic modulus of the first adhesive layer 212 is greater than that of the second adhesive layer 211. Through the above arrangement, the first adhesive layer 212 has higher strength than the second adhesive layer 211, making it more resistant to impact and deformation.

[0045] In some embodiments, the second adhesive layer 211 is disposed between the heat exchange component 2 and the battery module 1. Heat transfer between the heat exchange component 2 and the battery module 1 is required to improve heat exchange efficiency. Therefore, the thermal conductivity of the first adhesive layer 212 is lower than that of the second adhesive layer 211. This results in better thermal conductivity of the second adhesive layer 211, allowing it to rapidly exchange heat between the heat exchange component 2 and the battery module 1, thereby improving heat exchange efficiency.

[0046] It should be noted that the first adhesive layer 212 is a structural adhesive used to bond and fix the structural components inside the battery pack. The first adhesive layer 212 has the characteristics of high strength, ability to withstand large loads, aging resistance, fatigue resistance, corrosion resistance, and stable performance within its expected lifespan, thereby improving the connection strength between the heat exchange component 2 and the housing 3. The material of the first adhesive layer 212 can be an insulating material doped with a conductive medium. The first adhesive layer 212 can use an insulating material as the base material, that is, a non-conductive adhesive, such as epoxy resin, silicone rubber, polyurethane, etc. Therefore, the first adhesive layer 212 can be an epoxy resin structural adhesive or a polyurethane structural adhesive. In some embodiments, the first adhesive layer 212 can be a two-component epoxy resin structural adhesive, a two-component acrylic structural adhesive, a two-component polyurethane structural adhesive, or a two-component silane structural adhesive.

[0047] It should be noted that the second adhesive layer 211 is a thermally conductive structural adhesive used to fix the battery module 1 and the heat exchange component 2, and to achieve thermal conductivity between the two. The second adhesive layer 211 includes, but is not limited to, silicone thermally conductive adhesive, polyurethane thermally conductive structural adhesive, epoxy resin thermally conductive adhesive, etc.

[0048] In some embodiments, the relationship between the thickness d1 mm of the first adhesive layer 212 and the thickness d2 mm of the second adhesive layer 211 satisfies: d1 mm ≤ d2 mm.

[0049] The above configuration gives the first adhesive layer 212 higher strength, making it more resistant to impact and deformation. The second adhesive layer 211 further improves the heat exchange rate and reduces the risk of deformation of the heat exchange tube 21.

[0050] In other embodiments, please refer to Figure 7 A third adhesive layer 213 is provided on both sides along the width direction of the heat exchange tube 21, and the third adhesive layer 213 is connected to the first adhesive layer 212 and / or the second adhesive layer 211.

[0051] It is understood that the width direction of the heat exchange tube 21 refers to the direction along which the cross-section of the heat exchange tube 21 is larger, taken along a plane perpendicular to its extension direction. A third adhesive layer 213 is filled on both sides of the width direction of the heat exchange tube 21. The third adhesive layer 213 can be connected to the first adhesive layer 212, the second adhesive layer 211, or both simultaneously. The material of the third adhesive layer 213 can be the same as that of the first adhesive layer 212 or the second adhesive layer 211.

[0052] Through the above settings, the third adhesive layer 213 can limit the two sides of the heat exchange tube 21 to a certain extent in the width direction, making it less likely for the heat exchange tube 21 to shift and detach from the battery module 1 or the support plate 31. In this embodiment, it is further limited to satisfying: 0.94≤K / T≤35. For example, K / T can be 0.94, 1.58, 2.51, 3.25, 4.05, 5.52, 6.57, 7.8, 9.25, 10.25, 15.25, 20.58, 26.25, 29.54, 30.45, 35, etc., or any value between any two adjacent values ​​mentioned above. Making the K / T value appropriately small prevents the heat exchange tube 21 from breaking due to insufficient lateral deformation when its deformation is large.

[0053] In some embodiments, the elastic modulus of the third adhesive layer 213 is ≤500MPa. This allows the third adhesive layer 213 to allow the heat exchange tube 21 to undergo a certain degree of lateral deformation when subjected to compressive force, thus preventing the heat exchange tube 21 from breaking due to its inability to undergo lateral deformation.

[0054] In some embodiments, a third adhesive layer 213 is disposed between two adjacent heat exchange tubes 21 and connects the two adjacent heat exchange tubes 21 respectively. It is understood that the third adhesive layer 213 can fill between the sides of two adjacent heat exchange tubes 21, thereby limiting the two sides of the heat exchange tubes 21 to a certain extent, further preventing the heat exchange tubes 21 from shifting and detaching from the battery module 1 or the support plate 31. In this embodiment, the distance between two adjacent heat exchange tubes 21 is L1 mm, further defined as: 15 mm ≤ L1 mm ≤ 200 mm. For example, L1 mm can be 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm, 115mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, etc., or any value between any two adjacent values ​​mentioned above. By limiting the distance L1 mm between two adjacent heat exchange tubes 21 to the range of 15mm to 200mm, the heat exchange efficiency can be improved. When L1 mm < 15 mm, the distance between two adjacent heat exchange tubes 21 is too small, which will cause heat exchange interference between the heat exchange tubes 21 and reduce the heat exchange efficiency of the battery. When L1 mm > 200 mm, the distance between two adjacent heat exchange tubes 21 is too large, the width of the third adhesive layer 213 will also be large, the heat exchange path will be long, resulting in poor heat exchange efficiency.

[0055] In some embodiments, please refer to Figure 5 The support plate 31 includes a groove 311, which protrudes in a direction away from the battery module 1, and the groove opening of the groove 311 faces the battery module 1. At least a portion of the heat exchange component 2 is disposed in the groove 311, and at least a portion of the third adhesive layer 213 is disposed in the groove 311 and connected to the groove sidewall of the groove 311.

[0056] It is understood that the groove 311 is formed by the support plate 31 protruding in the direction away from the battery module 1. The groove 311 faces the battery module 1 and can be used to accommodate the heat exchange tube 21 so that the heat exchange tube 21 can be accommodated in the groove 311 and connected to the battery module 1 for heat exchange.

[0057] By accommodating the heat exchange tube 21 within the groove 311 as described above, the space utilization and assembly efficiency of the internal space of the housing 3 can be improved. Simultaneously, the pressure exerted by the battery module 1 on the heat exchange component 2 can be reduced, avoiding the risk of deformation of the heat exchange tube 21 and improving heat exchange efficiency. Furthermore, the third adhesive layer 213 filling the sidewalls of the groove 311 can provide a certain degree of restraint on both sides of the heat exchange tube 21, further preventing the heat exchange tube 21 from shifting and detaching from the battery module 1 or the support plate 31, thus improving the stability of the heat exchange tube 21.

[0058] In some embodiments, please refer to Figure 5 The support plate 31 also includes a protrusion 312, which is disposed between two adjacent grooves 311. The protrusion 312 protrudes towards the battery module 1 and is connected to the battery module 1. It is understood that the protrusion 312 and the battery module 1 can be directly contacted or connected through a third adhesive layer 213. In some embodiments, the protrusion 312 is formed by the entire support plate 31 protruding towards the battery module 1, and the protrusion 312 can be a hollow structure.

[0059] With the above configuration, the protrusion 312 can be supported below the battery module 1, playing a major supporting role for the battery module 1, and preventing the weight of the battery module 1 from being entirely pressed on the heat exchange component 2, which would easily cause the heat exchange component 2 to deform and affect the heat exchange efficiency.

[0060] In some embodiments, the heat exchange tube 21 is accommodated within a groove 311, the plane of the groove opening of the groove 311 being higher than the surface of the heat exchange tube 21 facing the battery module 1, and further defined to satisfy: 0.5 mm ≤ d2 mm ≤ 2.8 mm. In this embodiment, the area of ​​the groove opening of the groove 311 that is higher than the surface of the heat exchange tube 21 needs to be filled by the second adhesive layer 211. In this case, in order to improve the heat exchange efficiency, the thickness d2 mm of the second adhesive layer 211 should not be too large. Therefore, the thickness d2 mm of the second adhesive layer 211 is limited to the range of 0.5 mm to 2.8 mm to avoid the heat exchange path being too long, resulting in poor heat exchange efficiency.

[0061] In some other embodiments, the surface of the heat exchange tube 21 facing the battery module 1 is higher than the plane where the groove 311 is located, and the distance between the surface of the heat exchange tube 21 facing the battery module 1 and the plane where the groove 311 is located is d3 mm, satisfying: d3 mm ≤ 2 mm. In this embodiment, since the other areas of the heat exchange tube 21 that are higher than the groove 311 need to be filled by the third adhesive layer 213 to ensure the flatness of the connection with the first surface 10 of the battery module 1, the thickness of the third adhesive layer 213 should not be too large. Therefore, the distance d3 mm between the surface of the heat exchange tube 21 facing the battery module 1 and the groove 311 is limited to no more than 2 mm, avoiding an excessively long heat exchange path that would affect the heat exchange efficiency.

[0062] In some embodiments, the surface of the protrusion 312 facing the battery module 1 is not lower than the surface of the heat exchange tube 21 facing the battery module 1. This allows the protrusion 312 to be supported below the battery module 1, preventing excessive weight of the battery module 1 from pressing on the heat exchange assembly 2, which could cause the heat exchange assembly 2 to deform and affect heat exchange efficiency.

[0063] In some embodiments, please refer to Figure 5 The wall thickness of the protrusion 312 is *a* mm, satisfying the condition: 0.6 mm ≤ *a* mm ≤ 3 mm. For example, *a* mm can be 0.6 mm, 0.9 mm, 1.3 mm, 1.7 mm, 2.1 mm, 2.5 mm, 2.9 mm, 3 mm, or any value between any two adjacent values ​​mentioned above. This design ensures that the protrusion 312 has sufficient supporting strength to prevent deformation under the pressure of the battery module 1, which could lead to deformation of the heat exchange tube 21. When *a* mm < 0.6 mm, the wall thickness of the protrusion 312 is too small, and under the weight of the battery module 1, it is prone to deformation. This causes the weight of the battery module 1 to act on the heat exchange component 2, making the heat exchange component 2 easily deformed and affecting the heat exchange efficiency of the battery. When *a* mm > 3 mm, the wall thickness of the protrusion 312 is too large, which would affect the weight of the support plate 31.

[0064] In some embodiments, please refer to Figure 5 On a plane perpendicular to the length direction of the groove 311, the groove opening size of the groove 311 is larger than the bottom wall size of the groove 311.

[0065] It can be understood that the groove 311 can be arranged in a manner where the opening gradually decreases from the groove opening towards the bottom wall of the groove. The groove sidewall and the groove bottom wall of the groove 311 can be smoothly connected by an arc, and the groove sidewall and the protrusion 312 can be smoothly connected by an arc. With this arrangement, when the battery is subjected to vibration, the sharp corners of the support plate 31 can be prevented from damaging the battery module 1 and affecting the battery safety.

[0066] In some other embodiments, the battery further includes a separator plate disposed between the battery module 1 and the heat exchange assembly 2, and connected to both the battery module 1 and the heat exchange assembly 2 respectively. The separator plate is connected to both the battery module 1 and the heat exchange assembly 2 via a second adhesive layer 211. It should be noted that the separator plate supports the battery module 1, distributes the weight of the battery, increases the pressure-bearing area of ​​the heat exchange assembly 2, and prevents excessive local pressure on the heat exchange assembly 2, which could lead to deformation. The separator plate can be a flat plate structure, laid flat between the battery module 1 and the heat exchange assembly 2. The upper and lower sides of the separator plate are connected to the battery module 1 and the heat exchange assembly 2 respectively via the second adhesive layer 211. The separator plate can be made of various materials, such as high-strength materials like aluminum, aluminum alloy, copper, steel, and stainless steel, or at least one of polytetrafluoroethylene, metal, carbon fiber, mica, and ceramic.

[0067] By setting a partition plate between the battery module 1 and the heat exchange assembly 2, the partition plate can support the bottom of the battery module 1, preventing the battery module 1 from directly pressing onto the heat exchange assembly 2. This makes the stress on the heat exchange assembly 2 more uniform and less prone to deformation. In this embodiment, the thickness of the partition plate along the direction perpendicular to the first surface 10 is d4mm, satisfying: 0.2mm ≤ d4mm ≤ 2mm. For example, d4mm can be 0.2mm, 0.5mm, 0.8mm, 1.2mm, 1.6mm, 1.8mm, 2mm, etc., or any value between any two adjacent values ​​mentioned above. This allows for the distribution of stress on the battery module 1 while improving heat exchange efficiency. When d4mm is less than 0.2mm, the thickness of the partition plate is too small, and the partition plate is prone to deformation under the weight of the battery module 1, failing to effectively support the battery module 1. This results in excessive weight of the battery module 1 acting on the heat exchange tube 21, making the heat exchange tube 21 prone to breakage. When d4 mm is greater than 2 mm, the thickness of the separator plate is too large, which will reduce the heat exchange efficiency between the heat exchange component 2 and the battery module 1.

[0068] In some embodiments, the ratio of the sum of the projected areas of all heat exchange components 2 on the first surface 10 of the battery module 1 to the area of ​​the first surface 10 is c, satisfying that c ≥ 15%. For example, c can be 15%, 20%, 30%, 40%, etc., or any value between any two adjacent values ​​mentioned above. This setting ensures that the battery module 1 has sufficient heat exchange area, improves its heat exchange efficiency, and guarantees battery safety.

[0069] In some embodiments, please refer to Figure 6 In a plane perpendicular to the length of the heat exchange tube 21, the heat exchange tube 21 includes two oppositely arranged straight sections 2110, one of which is heat-exchange connected to the first surface 10 of the battery module 1. That is, in a longitudinal section perpendicular to the length of each heat exchange tube, the heat exchange tube 212 has two oppositely arranged straight sections 2110, which are used for heat exchange connection to the first surface 10 of the battery module 1. This arrangement increases the heat exchange area between the heat exchange tube 21 and the battery module 1, thereby improving the battery's heat exchange efficiency.

[0070] In some embodiments, please refer to Figure 6 Along the width direction of the heat exchange tube 21, the dimension of the straight section 2110 is L0 mm, satisfying: 3 mm ≤ L0 mm ≤ 44 mm. For example, L0 mm can be 3 mm, 8 mm, 10 mm, 18 mm, 25 mm, 30 mm, 37 mm, 41 mm, 44 mm, etc., or any value between any two adjacent values ​​mentioned above. In this way, the dimension of the straight section 2110 is controlled within the above range to ensure that there is sufficient heat exchange surface between the heat exchange tube 21 and the battery module 1, while also avoiding excessive flow resistance of the heat exchange medium inside the heat exchange tube 21, which would affect the heat exchange efficiency. When L0 mm is less than 3 mm, the size of the straight section 2110 is too small, the heat exchange surface between the heat exchange tube 21 and the battery module 1 is too small, and the heat exchange efficiency of the battery module 1 is poor. When L0 mm is greater than 44 mm, the size of the straight section 2110 is too large, which will make the heat exchange tube 21 relatively flat, and the flow resistance of the heat exchange medium inside the heat exchange tube 21 will be large, resulting in a slower flow rate of the heat exchange medium, which will reduce the heat exchange efficiency of the battery.

[0071] In some embodiments, please refer to Figure 6Along the width direction of heat exchange tube 21, the total width of heat exchange tube 21 is W1 mm, and along the thickness direction of heat exchange tube 21, the total thickness of heat exchange tube 21 is T1 mm, satisfying: 2.1 ≤ W1 / T1 ≤ 9. For example, W1 / T1 can be 2.1, 2.9, 3.1, 3.7, 4.3, 4.9, 5.5, 6.3, 7.1, 7.8, 8.6, 9, etc., or any value between any two adjacent values ​​mentioned above. Through the above settings, while improving heat exchange efficiency, the heat exchange tube 21 also has a certain strength and is not easily deformed. When W1 / T1 is less than 2.1, the contact area between heat exchange tube 21 and battery module 1 will be too small, resulting in poor heat exchange efficiency of battery module 1. When W1 / T1 is greater than 9, the heat exchange tube 21 will be relatively flat, and the flow resistance of the heat exchange medium inside the heat exchange tube 21 will be large, resulting in a slower flow rate of the heat exchange medium, which will reduce the heat exchange efficiency of the battery. In addition, if the total width W1 mm ​​of the heat exchange tube 21 is too large, the heat exchange tube 21 will be easily squeezed and deformed by the battery module 1, affecting the heat exchange efficiency.

[0072] In some embodiments, please refer to Figure 6 The two straight sections 2110 of the heat exchange tube 21 are connected by an arc section 2111. The connection between the two straight sections 2110 of the heat exchange tube 21 by the smoothly transitioning arc section 2111 reduces the flow resistance of the heat exchange medium in the heat exchange channel 2112, improves the uniformity of the flow velocity of the heat exchange medium, and thus improves the heat exchange efficiency.

[0073] In some embodiments, the inner fillet radius R mm of the arc segment 2111 satisfies: 1.5mm ≤ R mm ≤ 5mm. For example, the inner fillet radius R mm of the arc segment 2111 can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4.5mm, 5mm, etc., or any value between any two adjacent values ​​mentioned above.

[0074] Through the above settings, heat exchange efficiency is improved while ensuring the heat exchange tube 21 has sufficient strength to prevent deformation. When R mm is less than 1.5 mm, the heat exchange tube 21 becomes relatively flat, resulting in greater flow resistance of the heat exchange medium inside the tube 21 and a slower flow rate, which reduces the heat exchange efficiency of the battery. Furthermore, an excessively large straight section 2110 can cause the heat exchange tube 21 to be easily deformed by the battery module 1, affecting heat exchange efficiency. When R mm is greater than 5 mm, the straight section 2110 becomes too small, resulting in a small contact area between the heat exchange tube 21 and the battery module 1, leading to poor heat exchange efficiency of the battery module 1.

[0075] Of course, in some other embodiments, the cross-section of the heat exchange tube 21 may also be square, trapezoidal or circular in a plane perpendicular to the length direction of the heat exchange tube 21.

[0076] In some embodiments, on the plane containing the first surface 10, at least a portion of the orthographic projection of the bent segment 22 overlaps with the battery module 1, and the ratio between the wall thickness of the bent segment 22 and the wall thickness of the heat exchange tube 21 is x, satisfying: x ≥ 0.4. For example, x can be 0.4, 0.9, 1.2, 2.5, 2.8, etc., or any value between any two adjacent values ​​mentioned above.

[0077] It is understandable that at least a portion of the bent section 22 exchanges heat with the battery module 1.

[0078] The above settings ensure the structural strength of the bending section 22, improve the heat exchange efficiency of the bending section 22, and avoid the problem of large temperature difference between the individual cells 111 at the bending section 22 and the individual cells 111 at the heat exchange tube 21.

[0079] In some embodiments, please refer to Figure 9 The heat exchange assembly 2 includes an inlet 23 and an outlet 24. The plurality of heat exchange tubes 21 include at least a first heat exchange tube 214 and a second heat exchange tube 215. The inlet 23 is connected to the first heat exchange tube 214, and the outlet 24 is connected to the second heat exchange tube 215. The first heat exchange tube 214 and the second heat exchange tube 215 are connected. The heat exchange assembly 2 is an integrally connected structure.

[0080] It is understood that the first heat exchange tube 214 is the heat exchange tube connected to the inlet 23 among the multiple heat exchange tubes 21 of the heat exchange assembly 2, and the second heat exchange tube 215 is the heat exchange tube connected to the outlet 24 among the multiple heat exchange tubes 21 of the heat exchange assembly 2. The inlet 23, the outlet 24, and the multiple interconnected heat exchange tubes 21 constitute a heat exchange assembly 2. Through the above arrangement, the integrally connected heat exchange assembly 2 can reduce the flow resistance of the heat exchange medium and improve the heat exchange efficiency. The inlet 23 and the outlet 24 can be connected to the collector 25. The collector 25 is used to connect the inlet 23 and the outlet 24 of the heat exchange assembly 2 to collect and distribute the heat exchange medium, allowing the heat exchange medium to flow into the heat exchange channel 2112 of the heat exchange tube 21.

[0081] In some embodiments, the battery pack may include one, two, three, or even more sets of heat exchange components 2, for example Figure 8 The two sets of heat exchange components 2 shown are examples. However, they are not limited to these and can be designed according to needs.

[0082] In some embodiments, at least one of the cross-sections of the inlet 23 and the outlet 24 is circular on a plane perpendicular to the flow direction of the heat exchange medium.

[0083] It is understandable that the cross-section of inlet 23 can be circular, the cross-section of outlet 24 can be circular, or both the cross-sections of inlet 23 and outlet 24 can be circular.

[0084] By setting the cross-sections of inlet 23 and outlet 24 to be circular, it is easier to weld with the collector, improve the welding strength and sealing effect with the collector, and at the same time, the circular cross-section will make the cross-sectional area at inlet 23 and / or outlet 24 relatively larger than the cross-sectional area at other positions of heat exchange tube 21, which can increase the flow rate of heat exchange medium and reduce the flow resistance of heat exchange medium.

[0085] Of course, in some other embodiments, the cross-sections of the inlet 23 and the outlet 24 on a plane perpendicular to the flow direction of the heat exchange medium may also be square, elliptical or other irregular shapes.

[0086] In some embodiments, the battery module 1 includes at least two stacked individual cells 111, each cell 111 having a length direction, the length direction of the heat exchange tube 21 being perpendicular to the length direction of the individual cell 111, and on the plane of the first surface 10, each individual cell 111 overlaps with the orthographic projection of at least one heat exchange tube 21.

[0087] The above configuration allows more individual cells 111 to exchange heat with the same heat exchange tube 21, and each individual cell 111 can exchange heat with at least one heat exchange tube 21, thereby improving the temperature uniformity among individual cells 111 and thus improving the heat exchange effect.

[0088] Of course, in some other embodiments, the length direction of the heat exchange tube 21 may also be parallel to the length direction of the individual cell 111, and on the plane where the first surface 10 is located, each individual cell 111 overlaps with the orthographic projection of at least one heat exchange tube 21. This arrangement can improve the heat exchange area and heat exchange effect of the individual cell 111.

[0089] It should be noted that the single-cell battery 111 can store chemical energy and controllably convert it into electrical energy. In a recyclable single-cell battery, the active materials can be reactivated by charging after discharge for continued use. The single-cell battery 111 includes a casing, a cell, and other functional components. The cell is the component in the single-cell battery that undergoes an electrochemical reaction with the electrolyte. The cell includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the single-cell battery, the active materials repeatedly insert and extract between the positive and negative electrodes. The separator is disposed between the positive and negative electrodes, which can reduce short circuits between the positive and negative electrodes while allowing the passage of active material ions. In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector. In some embodiments, the negative electrode can be a negative electrode sheet, which may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector. In some embodiments, the separator is a membrane.

[0090] In some embodiments, to achieve faster battery charging rates, existing battery manufacturers introduce high-voltage charging platforms of 400V, 800V, or even 1200V. In this case, it is required to connect more individual battery cells 111 in series. To arrange more individual battery cells 111 within the same space, a preferred method is to reduce the thickness of the individual battery cells 111 and increase their length. In this case, when the length of the individual battery cell 111 is greater than 200mm, the total width of the heat exchange tube 21 is W1 mm, satisfying: 8mm ≤ W1 mm ​​≤ 50mm. For example, W1 mm ​​can be 8mm, 10mm, 16mm, 19mm, 21mm, 27mm, 32mm, 38mm, 45mm, 50mm, etc., or any value between any two adjacent values ​​mentioned above. In this embodiment, to ensure that the heat exchange tube 21 has sufficient heat exchange area along the length of the individual battery cell 111, the temperature uniformity of the individual battery cell 111 along its length is improved, thereby improving the overall heat exchange efficiency and temperature uniformity of the battery. In this embodiment, as... Figure 8 As shown, in order to further improve the heat exchange efficiency, at least two heat exchange tubes 21 have their orthogonal projections overlapping with the same single cell 111 on the plane of the first surface 10. That is, at least two heat exchange tubes 21 are heat exchanged with the same single cell 111, thereby further improving the heat exchange efficiency of the single cell 111 and improving the temperature uniformity of the single cell 111 along its length.

[0091] In some embodiments, when the weight of a single cell 111 is greater than or equal to 2 kg, the following condition is met: 1.3 ≤ K / T ≤ 35. In this embodiment, the weight of the single cell 111 is relatively large, the energy density of the battery will be relatively large, and the heat generation will also be relatively large. Therefore, K / T is further limited to the range of 1.3 to 35, thereby improving the heat exchange efficiency of the battery and ensuring the heat dissipation performance of the battery.

[0092] In some embodiments, the heat exchange tube 21 is made of aluminum alloy, which includes at least Al, Cu and Mn, wherein the mass percentage of Al is greater than or equal to 90 wt%, and the sum of the mass percentages of Cu and Mn is 1 wt% to 1.7 wt%.

[0093] The above-mentioned design improves the corrosion resistance of the heat exchange tube 21, making it less susceptible to corrosion by the heat exchange medium or surrounding gas, thereby increasing the strength of the heat exchange tube 21 and ultimately enhancing the overall safety of the battery.

[0094] In some other embodiments, the heat exchange tube 21 is made of stainless steel, which includes Cr, wherein the mass percentage of Cr is 15wt%~23wt%.

[0095] The above-mentioned design improves the corrosion resistance of the heat exchange tube 21, making it less susceptible to corrosion by the heat exchange medium or surrounding gas, thereby increasing the strength of the heat exchange tube 21 and ultimately enhancing the overall safety of the battery.

[0096] The battery pack provided in this application will be described in detail below through specific embodiments.

[0097] It should be noted that this application can use measuring instruments such as micrometers or calipers to measure parameters such as length, width, distance, thickness, and wall thickness.

[0098] Fabrication of single cell 111: (1) Preparation of the positive electrode: The prepared positive electrode active material, conductive agent (e.g., acetylene black), and binder (e.g., PVDF) are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, the positive electrode sheet is obtained by rolling and slitting.

[0099] Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98): (4~1): (4~1).

[0100] (2) Preparation of negative electrode: The negative electrode active material, conductive agent (e.g., acetylene black), thickener (e.g., carboxymethyl cellulose (CMC)), and binder (e.g., styrene-butadiene rubber (SBR)) are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, the negative electrode sheet is obtained by rolling and slitting.

[0101] Specifically, the ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96): (4~2): (2~1): (4~1).

[0102] (3) Preparation of electrolyte: Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0103] (4) Preparation of the diaphragm: Polyethylene film is selected as the diaphragm.

[0104] (5) Preparation of lithium-ion batteries: The positive electrode, separator, and negative electrode are stacked in sequence and formed into a bare cell by winding or stacking. The bare cell is then placed in a battery casing, which is a prismatic casing. The battery is dried, injected with electrolyte, and then packaged, allowed to stand, formed, and calibrated to obtain a lithium-ion battery.

[0105] Regarding the selection of materials for the aforementioned battery, this application may also choose other materials, not limited to those specified in the above preparation method. The positive electrode active material may be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate. The negative electrode active material may be selected from one or more negative electrode active main materials, including artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate. The conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P, etc.), carbon nanotubes, graphene, and carbon nanofibers. The binder includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan. The solvent can be deionized, NMP (N-methylpyrrolidone), alcohol, ether, ketone, or other types of pyrrolidone. The positive electrode current collector foil can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of silver-plated stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. A composite current collector may include a polymer substrate and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0106] The negative electrode current collector foil can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium, and can be surface-plated with silver. Composite current collectors may include a polymer base layer and a metal layer. Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, copper, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer base material (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0107] Performance tests are as follows: For each embodiment and comparative example, corresponding heat exchange components were prepared. Twenty measurement positions were selected on the heat exchange components, and the total thickness B0 of the heat exchange tube 21 was pre-measured. The selected positions needed to coincide with the projection of the first surface 10 of the battery module 1, and included at least five straight sections and five arc sections. A housing 3 was prepared, and the heat exchange component 2 was fixed to the support plate 31 of the housing 3 using the first adhesive layer 212. Following the single-cell preparation method described above, 200 single-cell batteries 111 were manufactured to form the battery module 1. The single-cell batteries 111 were then installed into the housing 3 to form a battery pack. The first surface 10 of the battery module 1 was fixedly connected to the heat exchange component 2 using the second adhesive layer 211. A heat exchange medium (ethylene glycol aqueous solution was selected as the heat exchange medium) was introduced into the heat exchange tube 21.

[0108] According to GB / T2423.43, the battery pack was mounted on a vibration table for performance testing. The testing procedure was carried out according to GB / T2423.56. Random and fixed-frequency vibration loads were applied in each direction, and the loading sequence should preferably be random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the direction connecting the front and rear of the battery pack is the x-axis direction, and the other horizontal direction perpendicular to the x-axis direction is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc. are shown in Table 1 below.

[0109] Table 1 Performance Test 1: Maximum Deformation of Heat Exchanger Tubes.

[0110] After vibration, the battery pack was disassembled, and the heat exchange assembly was removed. The total thickness B1 of the heat exchange tubes was measured again at the originally selected 20 measurement locations. The value of "B0-B1 / B0" corresponding to each measurement location was taken as the deformation of the heat exchange tube at that single point. The maximum value of the deformation at each point was taken as the maximum deformation of the heat exchange tubes of that heat exchange assembly. A maximum deformation of 0.03 mm or less is considered good; a maximum deformation of 0.5 mm or less but greater than 0.03 mm is considered acceptable; a maximum deformation of greater than 0.5 mm is considered unacceptable.

[0111] Performance Test 2: Number of individual cells with bonding failure.

[0112] After the vibration ends, disassemble the battery pack and count the number of individual cells that have detached from the battery pack. If the number of detached individual cells is less than or equal to 2, it is considered good; if the number of detached individual cells is less than or equal to 4 but greater than 2, it is considered qualified; if the number of detached individual cells is greater than 4, it is considered unqualified.

[0113] Table 2 Test parameters and results of Examples 1 to 17 and Comparative Examples 1 to 3 As shown in Table 2 above, compared to Comparative Examples 1 to 3, in Examples 1 to 17, when 0.94 ≤ K / T ≤ 39.20, the maximum deformation of the heat exchange tube 21 is less than or equal to 0.5, and performance 1 is qualified or good; the number of single cells 111 with bonding failure is less than or equal to 4, and performance 2 is qualified or good. However, in Comparative Examples 1 and 2, K / T is greater than 39.2, so the maximum deformation of the heat exchange tube 21 is greater than 0.5, indicating a large deformation of the heat exchange tube 21, and performance 1 is unqualified. In Comparative Example 3, K / T is less than 0.94, so the number of detached single cells is greater than 4, indicating insufficient bonding strength of the battery pack as a whole, and performance 2 is unqualified. In Comparative Example 1, the d1 mm value is greater than 1.5 mm, outside the range of 0.1 mm to 1.5 mm, and the d2 mm value is greater than 3 mm, outside the range of 1.5 mm to 3 mm. This results in a K mm value greater than 4.5 mm, outside the range of 0.6 mm to 4.5 mm, and a final K / T value greater than 39.2. Consequently, the maximum deformation of the heat exchange tube 21 is too large, and performance 1 is deemed unqualified. In Comparative Example 2, the T value is less than 0.107, outside the range of 0.107 to 0.737, resulting in a final K / T value greater than 39.2. This also results in a maximum deformation of the heat exchange tube 21, and performance 1 is deemed unqualified. In Comparative Example 3, the d1 mm value is within the range of 0.1 mm to 1.5 mm, but the d2 mm value is less than 0.5 mm, outside the range of 0.5 mm to 3 mm. This results in a K mm value less than 0.6 mm, and a final K / T value less than 0.94. The excessive number of single-cell cells 111 with bonding failure leads to performance 2 being deemed unqualified.

[0114] Compared to Examples 4 to 11, Examples 1 to 3 have relatively larger K / T values, resulting in a larger maximum deformation of the heat exchange tube 21. Therefore, the maximum deformation of the individual cells in Examples 4 to 11 is relatively smaller, while the maximum deformation of the individual cells in Examples 1 to 3 is relatively larger. Performance 1 of Examples 1 to 3 is qualified, while performance 1 of Examples 4 to 11 is good. However, compared to Examples 4 to 11, Examples 12 to 17 have relatively smaller K / T values, resulting in a relatively weaker connection strength of the individual cells 111. The number of individual cells with bonding failures in Examples 12 to 17 is relatively larger than that in Examples 4 to 11. Performance 2 of Examples 12 to 17 is qualified, while performance 2 of Examples 4 to 11 is good.

[0115] Compared to Examples 1 to 15, although the K / T values ​​in Examples 16 and 17 are within the range of 0.94 to 39.2, in Example 16, K mm is less than 0.6 mm and does not fall within the range of 0.6 mm to 4.5 mm. The sum of the thicknesses of the first adhesive layer (d1 mm) and the second adhesive layer (d2 mm) is too small, leading to a higher risk of detachment of the individual cell 111. Therefore, the number of individual cells 111 with bonding failure is relatively large, and performance 2 is considered acceptable. In Example 17, the T value is greater than 0.737 and does not fall within the range of 0.107 to 0.737, resulting in a smaller K / T value. In Example 17, the number of individual cells with bonding failure is relatively large, and performance 2 in Example 17 is considered acceptable.

[0116] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements 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, include: The box (3) has a receiving space and the box (3) includes a support plate (31). The battery module (1) includes at least two individual batteries (111) housed in the housing space. The battery module (1) is disposed on the support plate (31) and has a first surface (10). At least one heat exchange assembly (2) is disposed between the support plate (31) and the battery module (1) and is heat-exchange connected to the first surface (10) of the battery module (1). The heat exchange assembly (2) is connected to the support plate (31) through a first adhesive layer (212) and to the first surface (10) of the battery module (1) through a second adhesive layer (211). The heat exchange assembly (2) includes a plurality of spaced heat exchange tubes (21), which are connected by bends (22). The heat exchange tubes (21) are provided with heat exchange channels (2112) that allow the heat exchange medium to pass through. The thickness of the first adhesive layer (212) is d1 mm and the thickness of the second adhesive layer (211) is d2 mm along the direction perpendicular to the support plate (31). d1 mm + d2 mm = K mm; along the direction perpendicular to the support plate (31), the ratio of the total wall thickness of the heat exchange tube (21) to the total thickness of the heat exchange tube (21) is T, which satisfies: 0.94≤K / T≤39.

20.

2. The battery pack according to claim 1, characterized in that, The elastic modulus of the first adhesive layer (212) is greater than that of the second adhesive layer (211); and / or, The thermal conductivity of the first adhesive layer (212) is less than that of the second adhesive layer (211).

3. The battery pack according to claim 1, characterized in that, The thickness d1 mm of the first adhesive layer (212) satisfies: 0.1 mm ≤ d1 mm ≤ 1.5 mm; and / or, The thickness d2 mm of the second adhesive layer (211) satisfies: 0.5 mm ≤ d2 mm ≤ 3 mm.

4. The battery pack according to claim 1, characterized in that, The relationship between the thickness d1 mm of the first adhesive layer (212) and the thickness d2 mm of the second adhesive layer (211) satisfies: d1 mm ≤ d2 mm.

5. The battery pack according to claim 1, characterized in that, A third adhesive layer (213) is provided on both sides along the width direction of the heat exchange tube (21), and the third adhesive layer (213) is connected to the first adhesive layer (212) and / or the second adhesive layer (211).

6. The battery pack according to claim 5, characterized in that, It satisfies: 0.94≤K / T≤35.

7. The battery pack according to claim 5, characterized in that, The elastic modulus of the third adhesive layer (213) is less than or equal to 500 MPa.

8. The battery pack according to claim 5, characterized in that, The third adhesive layer (213) is disposed between two adjacent heat exchange tubes (21) and is connected to the two adjacent heat exchange tubes (21) respectively.

9. The battery pack according to claim 8, characterized in that, The distance between two adjacent heat exchange tubes (21) is L1 mm, which satisfies: 15mm≤L1 mm≤200mm.

10. The battery pack according to claim 5, characterized in that, The support plate (31) includes a groove (311) that protrudes away from the battery module (1) and the opening of the groove (311) faces the battery module (1). At least a portion of the heat exchange component (2) is disposed in the groove (311), and at least a portion of the third adhesive layer (213) is disposed in the groove (311) and connected to the sidewall of the groove (311).

11. The battery pack according to claim 10, characterized in that, The support plate (31) also includes a protrusion (312), which is located between two adjacent grooves (311). The protrusion (312) protrudes toward the battery module (1) and is connected to the battery module (1).

12. The battery pack according to claim 10, characterized in that, The heat exchange tube (21) is housed in the groove (311), and the plane of the groove (311) is higher than the surface of the heat exchange tube (21) facing the battery module (1), and satisfies: 0.5mm≤d2mm≤2.8mm.

13. The battery pack according to claim 10, characterized in that, The heat exchange tube (21) is housed in the groove (311). The surface of the heat exchange tube (21) facing the battery module (1) is higher than the plane where the groove (311) is located. The distance between the surface of the heat exchange tube (21) facing the battery module (1) and the plane where the groove (311) is located is d3 mm, which satisfies: d3 mm≤2mm.

14. The battery pack according to claim 11, characterized in that, The surface of the protrusion (312) facing the battery module (1) is not lower than the surface of the heat exchange tube (21) facing the battery module (1); and / or, The wall thickness of the protrusion (312) is a mm, which satisfies: 0.6 mm ≤ a mm ≤ 3 mm.

15. The battery pack according to claim 10, characterized in that, On a plane perpendicular to the length direction of the groove (311), the opening size of the groove (311) is larger than the bottom wall size of the groove (311).

16. The battery pack according to any one of claims 1 to 15, characterized in that, Also includes: A separator plate is disposed between the battery module (1) and the heat exchange component (2) and is connected to the battery module (1) and the heat exchange component (2) respectively. The separator plate is connected to the battery module (1) and the heat exchange component (2) through the second adhesive layer (211). Along the direction perpendicular to the support plate (31), the thickness of the separator plate is d4 mm, which satisfies: 0.2mm≤d4 mm≤2mm.

17. The battery pack according to any one of claims 1 to 15, characterized in that, The ratio of the sum of the projected areas of all the heat exchange components (2) on the first surface (10) of the battery module (1) to the area of ​​the first surface (10) is c, which satisfies: c≥15%.

18. The battery pack according to any one of claims 1 to 15, characterized in that, On a plane perpendicular to the length direction of the heat exchange tube (21), the heat exchange tube (21) includes two straight sections (2110) arranged opposite each other, and one of the straight sections (2110) is heat-exchange connected to the first surface (10) of the battery module (1).

19. The battery pack according to claim 18, characterized in that, Along the width direction of the heat exchange tube (21), the dimension of the straight section (2110) is L0 mm, satisfying: 3mm ≤ L0 mm ≤ 44mm; and / or, Along the width direction of the heat exchange tube (21), the total width of the heat exchange tube (21) is W1 mm, and along the thickness direction of the heat exchange tube (21), the total thickness of the heat exchange tube (21) is T1 mm, satisfying: 2≤W1 / T1≤9.

20. The battery pack according to claim 18, characterized in that, The two straight segments (2110) that are set opposite to each other are connected by an arc segment (2111).

21. The battery pack according to claim 20, characterized in that, The inner fillet radius Rmm of the arc segment (2111) satisfies: 1.5mm≤R mm≤5mm.

22. The battery pack according to any one of claims 1 to 15, characterized in that, On the plane where the first surface (10) is located, at least a portion of the orthographic projection of the bent section (22) overlaps with the battery module (1), and the ratio between the wall thickness of the bent section (22) and the wall thickness of the heat exchange tube (21) is x, which satisfies: x≥0.

4.

23. The battery pack according to any one of claims 1 to 15, characterized in that, The heat exchange assembly (2) includes an inlet (23) and an outlet (24). The plurality of heat exchange tubes (21) include at least a first heat exchange tube (214) and a second heat exchange tube (215). The inlet (23) is connected to the first heat exchange tube (214), and the outlet (24) is connected to the second heat exchange tube (215). The first heat exchange tube (214) and the second heat exchange tube (215) are connected in communication. The heat exchange assembly (2) is an integrally connected structure.

24. The battery pack according to claim 23, characterized in that, On a plane perpendicular to the flow direction of the heat exchange medium, at least one of the cross-sections of the inlet (23) and the outlet (24) is circular.

25. The battery pack according to claim 23, characterized in that, The single cell (111) has a length direction, the length direction of the heat exchange tube (21) is perpendicular to the length direction of the single cell (111), and on the plane where the first surface (10) is located, each single cell (111) overlaps with the orthographic projection of at least one heat exchange tube (21).

26. The battery pack according to claim 25, characterized in that, The length of the single cell (111) is greater than 200mm, and the total width of the heat exchange tube (21) is W1 mm, satisfying: 8mm≤W1 mm≤50mm.

27. The battery pack according to claim 26, characterized in that, On the plane of the first surface (10), there are at least two of the heat exchange tubes (21) whose orthogonal projections overlap with the same single cell (111).

28. The battery pack according to any one of claims 1 to 15, characterized in that, When the weight of a single cell (111) is greater than or equal to 2kg, the following condition is met: 1.3≤K / T≤35.

29. The battery pack according to any one of claims 1 to 15, characterized in that, Satisfying: 0.6mm ≤ K mm ≤ 4.5mm; and / or, 0.107≤T≤0.737。 30. The battery pack according to any one of claims 1 to 15, characterized in that, The heat exchange tube (21) is made of aluminum alloy, which includes at least Al, Cu and Mn, wherein the mass percentage of Al is greater than or equal to 90wt%, and the sum of the mass percentages of Cu and Mn is 1wt%~1.7wt%.

31. The battery pack according to any one of claims 1 to 15, characterized in that, The heat exchange tube (21) is made of stainless steel, and the stainless steel material includes Cr, wherein the mass percentage of Cr is 15wt%~23wt%.

32. An electrical appliance, characterized in that, Includes the battery pack as described in any one of claims 1 to 31.

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