Multilayer composite thermal insulation structure and battery module

Abstract

The utility model belongs to the technical field of soft-pack batteries, and discloses a multi-layer composite thermal insulation structure and a battery module, wherein the multi-layer composite thermal insulation structure is arranged between adjacent battery cells, and includes a stacked fin layer, a phase-change thermal insulation layer, and a buffer foam layer, wherein the fin layer is in contact with the stacking surface of the battery cell; and the edge sealing of the phase-change thermal insulation layer is coated with a heat-resistant protective component. The present application can not only meet the requirements of achieving thermal conductivity and temperature uniformity, heat dissipation and cooling, reducing the peak temperature of the battery module, and providing battery expansion space in the thermal management system during normal operation, but also meet the requirements of thermal shock protection, heat dissipation, heat resistance, heat absorption, and heat insulation when the battery is in thermal runaway, and effectively prevent the propagation of thermal runaway between the battery cells inside the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of soft-pack batteries, and in particular to a multi-layer composite heat insulation structure and a battery module. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, low self-discharge, long cycle life and good cycle stability, but people are paying more and more attention to their safety. Accidents caused by lithium-ion batteries are always due to thermal runaway of a single battery due to abuse. If the thermal runaway propagation path cannot be cut off, the thermal runaway may spread to the entire battery pack, which will cause severe thermal disasters. Therefore, inhibiting or even preventing the spread of thermal runaway between batteries is crucial to ensure the safety of life and property of vehicle passengers. The invention patent with publication number CN217589142U proposes a solution, but the thermal insulation layer of this solution has no protection, is not resistant to the impact of battery thermal runaway, and the thermal insulation effect is not strong, so it is difficult to achieve a strong and effective protection effect, and it is impossible to effectively prevent the spread of thermal runaway of high-nickel ternary lithium-ion batteries.

[0003] Therefore, how to propose a thermal insulation structure that can effectively prevent the propagation of thermal runaway between high-nickel ternary batteries is an urgent problem to be solved. Utility Model Content

[0004] The main purpose of the utility model is to provide a multi-layer composite thermal insulation structure and a battery module, aiming to solve the technical problem of how to propose a thermal insulation structure that can effectively prevent the propagation of thermal runaway between high-nickel ternary batteries.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application proposes a multi-layer composite thermal insulation structure, which is arranged between adjacent battery cells, and is characterized in that it includes a stacked fin layer, a phase change insulation layer and a buffer foam layer, wherein the fin layer is bonded to the stacking surface of the battery cell; and the edge sealing of the phase change insulation layer is coated with a heat-resistant protective component.

[0006] Furthermore, the phase-change insulation layer comprises an insulating sealing layer, a flame-retardant phase-change material and an insulation layer, wherein the insulating sealing layer is a hollow structure, an insulation layer is arranged inside the insulating sealing layer and is filled with the flame-retardant phase-change material.

[0007] Furthermore, the phase-change heat-insulating layer is arranged between the fin layer and the buffer foam layer, and is attached to a side of the fin layer away from the battery core.

[0008] Furthermore, the buffer foam layer is arranged between the fin layer and the phase change insulation layer.

[0009] Furthermore, a side of the phase change thermal insulation layer close to the fin layer is coated with a heat-resistant protection component.

[0010] Furthermore, the extension length of the fin is less than or equal to the thickness of the battery core.

[0011] Furthermore, two opposite sides of each of the fin layers extend along the stacking direction of the battery cells to form extended fins.

[0012] Furthermore, the thickness of the heat-resistant protection component ranges from 0.1 to 1 mm.

[0013] Furthermore, the material of the fin layer is one or more of aluminum, copper, aluminum alloy or copper alloy, and the thickness is 0.1 mm to 0.6 mm.

[0014] Furthermore, the thickness of the phase-change thermal insulation layer is 1 mm to 4 mm, and the size of the phase-change thermal insulation layer is greater than or equal to the size of the battery stacking surface.

[0015] Furthermore, the thickness of the buffer foam layer is 0.8 mm to 3 mm, and the outer contour size of the buffer foam layer is greater than or equal to the size of the battery stacking surface.

[0016] Furthermore, the fin layer is provided on one stacking surface of the battery cell, the stacking surface of the battery cell away from the fin layer is bonded to another battery cell, and the fin layers of every two battery cells are arranged opposite to each other and the phase change insulation layer and the buffer foam layer are provided between the fin layers of every two battery cells.

[0017] Furthermore, the buffer foam layer is arranged between the two battery cells, the fin layer is arranged on the stacking surface of the battery cell away from the buffer foam, and the phase change insulation layer is arranged on the side of the fin layer away from the battery cell.

[0018] The second aspect of the present application further proposes a battery module, comprising a plurality of battery cells, wherein the plurality of battery cells are stacked and the above-mentioned multi-layer composite thermal insulation structure is arranged between adjacent battery cells.

[0019] Beneficial effects:

[0020] The utility model adopts a multi-layer composite insulation structure to separate two adjacent battery cells, which solves the problem of thermal runaway transmission between batteries. Specifically, when the battery is in thermal runaway, the fin layer has the functions of preventing thermal shock and dissipating heat, the phase change insulation layer has the functions of absorbing heat and insulating heat, the heat-resistant protective component has the function of heat resistance, and the phase change insulation layer is coated with a heat-resistant protective component to enhance the anti-impact ability of the phase change insulation layer. This solution can not only meet the requirements of achieving thermal conductivity and temperature uniformity, heat dissipation and cooling, reducing the peak temperature of the battery module, and providing battery expansion space in the thermal management system during normal operation, but also meet the requirements of preventing thermal shock, dissipating heat, heat resistance, absorbing heat, and insulating when the battery is in thermal runaway, effectively preventing the spread of thermal runaway between the battery cells inside the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of a battery module in one embodiment of the multi-layer composite heat insulation structure and battery module of the utility model.

[0022] Figure 2 In one embodiment of the utility model, a multi-layer composite heat insulation structure and a battery module are provided. Figure 1 A partial enlarged view of part A.

[0023] Figure 3 This is a schematic structural diagram of a heat-resistant protective component wrapped around a phase-change insulation layer and sealing edges of an embodiment of a multi-layer composite insulation structure and a battery module of the utility model.

[0024] Figure 4 It is a schematic structural diagram of a heat-resistant protective component wrapped around a bonding surface of a phase-change thermal insulation layer in one embodiment of the multi-layer composite thermal insulation structure and battery module of the utility model.

[0025] Figure 5 It is a structural schematic diagram of the connection of multiple groups of battery cells in one embodiment of the multi-layer composite thermal insulation structure and battery module of the utility model.

[0026] Figure 6 It is a structural schematic diagram of the connection of multiple groups of battery cells in one embodiment of the multi-layer composite thermal insulation structure and battery module of the utility model.

[0027] Figure 7 It is a schematic diagram of a curve of temperature variation over time during a thermal runaway test of a battery module of a multi-layer composite thermal insulation structure and a battery module according to an embodiment of the utility model.

[0028] Figure 8 It is a schematic diagram of the curve of the temperature change over time during the thermal runaway test of the battery module of Comparative Example 2 of the multi-layer composite thermal insulation structure and the battery module of one embodiment of the utility model.

[0029] Among them: 1. battery core; 2. multi-layer composite insulation structure; 21. fin layer; 22. phase change insulation layer; 23. buffer foam layer; 221. heat-resistant protection component;

[0030] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0034] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] Reference Figures 1 to 8 The utility model proposes a battery module with a multi-layer composite insulation structure 2, which is arranged between adjacent battery cells 1, and includes a stacked fin layer 21, a phase change insulation layer 22 and a buffer foam layer 23, wherein the fin layer 21 is in contact with the stacking surface of the battery cell; the edge sealing of the phase change insulation layer 22 is coated with a heat-resistant protective component 221.

[0036] In this embodiment, the multi-layer composite thermal insulation structure 2 includes a fin layer 21, a phase change thermal insulation layer 22 and a buffer foam layer 23, wherein the fin layer 21, the phase change thermal insulation layer 22 and the buffer foam layer 23 are stacked in a preset order according to actual needs, wherein the fin layer 21 is bonded to the stacking surface of the battery cell, and the stacking surface is the adjacent surface (bonding surface) between two adjacent battery cells in the battery cell stack, which is used to achieve thermal conductivity and temperature equalization, heat dissipation and cooling of the thermal management system during normal operation, reduce the peak temperature of the battery module, increase the mechanical strength of the module, and prevent the impact of flame and smoke when the battery is thermally runaway. In addition, it can play a certain protective role on the buffer foam layer 23 and the phase change thermal insulation layer 22, and has a good heat dissipation effect, which can accelerate the cooling of the runaway battery cell 1 and the remaining battery cells 1. The phase change thermal insulation layer 22 has a heat absorption effect, which can achieve the functions of thermal conductivity and temperature equalization, heat dissipation and cooling, and reduce the peak temperature of the battery module when the module is working normally. When the battery thermally runs away, the phase change insulation layer 22 can absorb the heat of the failed battery, reduce the peak temperature of the failed battery, and block the heat from being transferred to the surrounding batteries, protecting the remaining batteries from thermal runaway. The buffer foam layer 23 is used to provide space for battery expansion and has a certain thermal insulation effect.

[0037] Although the flame-retardant phase change material can absorb and release a large amount of heat to achieve temperature control and stability of the battery module. When the battery is in thermal runaway, the battery module overheats, and the flame-retardant phase change material will absorb a large amount of heat (from solid to liquid or gas) and convert it into latent heat. This can effectively prevent the battery module from overheating and reduce safety risks such as fire. However, in extreme cases, such as when the battery is out of control and a fire occurs, the thermal radiation of the high-temperature flame and the chemical action of the smoke may cause the edge sealing to melt, deform or peel off, thereby causing the flame and smoke to further penetrate into the phase change insulation layer 22, resulting in leakage, melting, burning or decomposition of the flame-retardant phase change material. The destruction of the flame-retardant phase change material will cause the release of more heat and gas, and even cause fires and safety accidents. At this time, the heat-resistant protection component 221 is coated on the edge sealing of the phase change insulation layer 22, which can be specifically as follows Figure 3As shown, the heat-resistant protective component 221 is coated on the edge sealing of the side of the phase change insulation layer 22 that is prone to eruption, which plays a protective role and can reduce consumables. In addition, the number and position of the edge sealing can be adjusted according to actual needs. For example, the edge sealing on all sides is coated with the heat-resistant protective component 221, etc. The heat-resistant protective component 221 can be used as a protective layer for the phase change insulation layer 22, wherein the width of the heat-resistant protective component 221 is greater than or equal to twice the width of the edge sealing of the phase change insulation layer 22, which can effectively prevent high-temperature flames and smoke from breaking through the edge sealing, avoid leakage of flame-retardant phase change materials, and ensure the normal operation and performance of the phase change insulation layer 22. In addition, the heat-resistant protective component 221 can also improve the durability and service life of the battery module and reduce maintenance and replacement costs. For the selection of the heat-resistant protective component 221, it is possible to consider using materials with good high temperature resistance and flame retardant properties. For example, common heat-resistant protective materials include: such as polyether ketone (PEEK), polyimide (PI), etc. These polymers have excellent high temperature resistance and flame retardant properties, and can effectively protect the phase change insulation layer 22. For example, ceramic fiber cloth, ceramic fiber paper, etc. Ceramic fiber has good high temperature resistance and heat insulation properties, and can effectively isolate high temperature flames and smoke. Alternatively, a flame retardant coating can be applied to the edge of the phase change insulation layer 22 to improve the high temperature resistance and flame retardant properties of the edge. Common flame retardant coating materials include flame retardant coatings, flame retardant adhesives, etc.

[0038] As shown in the following table, the experimental detailed information of the multilayer composite thermal insulation structure 2 of this embodiment is compared with that of the comparative example, wherein the multilayer composite thermal insulation structure 2 is composed of a module with a positive electrode high nickel 9 series NCM, a negative electrode composed of silicon and carbon, and a soft pack battery with a uniform capacity of 84Ah, and the battery is fully charged, and the thermal insulation protection effect of the multilayer composite thermal insulation structure 2 in the module is tested:

[0039]

[0040] As shown in the table above and Figure 7 - Figure 8 As shown, (where Figure 7 - Figure 8 The ordinate in the coordinate system is temperature, in units of °C; the abscissa is time, in units of S). In this experiment, the first battery cell 1 is triggered by a heating plate, and temperature sensors are used to record the temperature of the heating plate (T1), the center temperature of the rear large surface of the first battery cell 1 (T2), and the center temperature of the front large surface of the second battery cell (T3). The thermal runaway propagation time is the time difference from the time when the thermal runaway occurs in the first battery cell to the time when the thermal runaway occurs in the second battery cell.

[0041] Through comparative analysis in Table 1, the multi-layer composite thermal insulation structure 2 proposed in the present application can prevent the thermal runaway from propagating between high-nickel 9-series ternary batteries, and control the thermal runaway within the single battery. However, the use of other thermal insulation structures causes the thermal runaway of the battery to propagate. The thermal runaway propagation time of comparative example 1 is 210s, and the thermal runaway propagation time of comparative example 2 is 79s. Figure 7 and Figure 8 They are the experimental temperature curves of Example 2 and Comparative Example 2, respectively. According to the change in the front surface temperature of the second battery in the figure, it can be intuitively seen that the battery module using the multi-layer composite insulation structure 2 designed in Example 2 did not experience thermal runaway propagation, while the battery module using other insulation structures designed in Comparative Example 2 had the second battery section heat up rapidly in a short period of time and thermal runaway propagation occurred.

[0042] In one embodiment, the phase change insulation layer 22 includes an insulating sealing layer, a flame retardant phase change material and an insulation layer, wherein the insulating sealing layer is a hollow structure, an insulation layer is arranged inside the insulating sealing layer and is filled with the flame retardant phase change material.

[0043] In this embodiment, the phase change insulation layer 22 is composed of three parts, including an insulating sealing layer, a flame retardant phase change material and a thermal insulation layer. The selection of these three materials is to provide good insulation, flame retardancy and thermal insulation properties to protect the safety of the battery module. First, the insulating sealing layer is mainly used to wrap the flame retardant phase change material and the thermal insulation layer, which plays a role in isolating the internal and external environment of the battery. Common insulating sealing layers can be made of polymer materials such as polyimide (PI), polytetrafluoroethylene (PTFE), etc. These materials have good high temperature resistance and insulation properties; secondly, the flame retardant phase change material plays a role in absorbing heat when the battery is thermally runaway, and has the function of preventing the spread of flames. It can include solid, solid or glassy states, and can be filled or arranged in the insulating sealing layer. When it is liquid, the thermal insulation layer is immersed in the flame retardant phase change material. When the battery temperature rises, the flame retardant phase change material absorbs heat for phase change, thereby reducing the temperature of the battery and preventing the spread of flames; finally, the thermal insulation layer is used to reduce heat conduction and prevent heat from being transferred to the surrounding environment. Common thermal insulation layers can be selected from silica gel, ceramic fiber, graphene, etc. These materials have low thermal conductivity and can effectively isolate the heat transfer inside and outside the battery module. By wrapping the flame-retardant phase change material and the thermal insulation layer in the insulating sealing layer, the function of the phase change thermal insulation layer 22 can be realized. At the same time, since heat is generated between the battery cells 1 in the battery pack, especially during high-power discharge or charging, by wrapping the flame-retardant phase change material and the thermal insulation layer in the insulating sealing layer, it can help control the temperature of the battery cell 1, prevent overheating, and improve the safety performance of the battery. In addition, there may be temperature differences between different battery cells 1 in the battery pack, which will lead to uneven performance of the battery pack. Materials with phase change characteristics can absorb heat and release heat when needed, thereby achieving thermal balance between the battery cells 1 and improving the performance and life of the entire battery pack.

[0044] In one embodiment, the phase change heat insulation layer 22 is disposed between the fin layer 21 and the buffer foam layer 23 , and is attached to a side of the fin layer 21 away from the battery core 1 .

[0045] In this embodiment, the fin layer 21 is usually made of a material with high thermal conductivity, such as aluminum alloy. Their function is to increase the heat dissipation surface area and improve the heat dissipation efficiency. The phase change insulation layer 22 is arranged between the fin layer 21 and the buffer foam layer 23, which can isolate the battery cell 1 and other components to a certain extent to prevent heat conduction and flame spread. At the same time, the phase change insulation layer 22 is bonded to the fin layer 21, which can provide a better heat dissipation effect. The buffer foam layer 23 can be made of soft polyester fiber and other materials, which have good mechanical buffering and shock absorption properties, can protect the battery cell 1 from external impact and vibration damage, and increase the mechanical stability and durability of the battery module.

[0046] In one embodiment, the buffer foam layer 23 is disposed between the fin layer 21 and the phase change insulation layer 22 .

[0047] In this embodiment, the buffer foam layer 23, as a soft material, can provide an additional insulation layer between the fin layer 21 and the phase change insulation layer 22. This can reduce the conduction of heat in the vertical direction and concentrate the heat more in the horizontal direction, thereby increasing the heat dispersion effect. The phase change insulation layer 22 usually achieves the insulation effect through a flame retardant phase change material, such as flame retardant polyethylene wax (FR-PEW). Laying the buffer foam layer 23 to one side of the phase change insulation layer 22 can provide additional protection. In summary, the buffer foam layer 23 is arranged between the fin layer 21 and the phase change insulation layer 22, and the phase change insulation layer 22 is laminated to the side of the buffer foam layer 23 away from the fin layer 21, which can provide better heat dispersion effect, protect the phase change insulation layer 22, and improve mechanical buffering performance. This can further improve the heat dissipation efficiency and safety performance of the battery module.

[0048] In one embodiment, a side of the phase change insulation layer 22 close to the fin layer 21 is coated with a heat-resistant protection component 221 .

[0049] like Figure 4As shown, in this embodiment, the side of the phase change insulation layer 22 close to the fin layer 21 is coated with a heat-resistant protective component 221. Since the phase change insulation layer 22 has a heat absorption effect, the side close to the fin 21 is also closer to the battery cell 1. When the battery cell 1 dissipates heat or thermal runaway occurs, the side close to the battery cell 1 faces stronger heat, so this side is also coated with the heat-resistant protective component 221. The protective ability of the phase change insulation layer 22 can be enhanced, and the risk of leakage of the phase change insulation layer 22 in extreme cases can be reduced. In this case, the edge-sealed heat-resistant protective component 221 is preferably coated with the heat-resistant protective component 221 on all sides. Figure 6 As shown, when the surrounding edges of the phase change insulation layer 22 are also covered, an uncovered area of ​​the heat-resistant protection component 221 is generated on the side away from the fin layer 21. At this time, the area of ​​the uncovered area of ​​the heat-resistant protection component 221 is less than or equal to the area of ​​the bonding surface of the phase change insulation layer 22.

[0050] In one embodiment, two opposite sides of each of the fin layers 21 extend along the stacking direction of the battery cells 1 to form extended fins.

[0051] In this embodiment, the opposite sides of each fin layer 21 extend along the stacking direction of the battery cell 1 to form extended fins, forming an overall "C"-shaped structure to wrap the battery cell 1. The extended fins further increase the heat dissipation effect of the fin layer 21, and at the same time can increase the mechanical strength of the battery module, and improve its shock resistance and durability.

[0052] In one embodiment, the extension length of the extension fin is less than or equal to the thickness of the battery core 1 .

[0053] In this embodiment, the fin layer 21 is used to increase the heat dissipation function between the battery cells 1. The two opposite sides of each fin layer 21 extend along the stacking direction of the battery cells 1 to form extended fins, that is, the fin layer 21 extends in the direction along the stacking direction of the battery cells 1. The extension length ranges from 0 to the thickness of the battery cell 1, which means that the extended fin will not exceed the thickness range of the battery cell 1 and will not have too much impact on the overall size of the battery pack. The length of the extended fin can be designed according to actual conditions, or whether to set the extended fin. This design can improve the heat dissipation performance of the battery pack, reduce problems such as battery heating and overheating, and improve the safety and performance of the battery pack.

[0054] In one embodiment, the thickness of the heat-resistant protection component 221 ranges from 0.1 to 1 mm.

[0055] In this embodiment, the thickness of the heat-resistant protective component 221 ranges from 0.1 to 1 mm. A suitable thickness can provide better heat insulation, reduce heat conduction and loss, and help maintain a stable operating temperature of the battery module. The specific thickness and material selection of the heat-resistant protective component 221 should be optimized and adjusted according to actual conditions to meet the requirements of specific applications.

[0056] In one embodiment, the fin layer 21 is made of one or more of aluminum, copper, aluminum alloy or copper alloy, and has a thickness of 0.1 mm to 0.6 mm.

[0057] In this embodiment, aluminum, copper, aluminum alloy or copper alloy is selected as the manufacturing material of the fin layer 21, and its thickness is controlled to be between 0.1 mm and 0.6 mm. Aluminum, copper, aluminum alloy or copper alloy has good thermal conductivity, can quickly conduct heat to the surface of the fin layer 21, increase the heat transfer area, improve the heat dissipation effect, and has a lower density, so the fin layer 21 is relatively light. While ensuring the heat dissipation performance, the weight of the entire system can be reduced, which helps to improve the portability and installation flexibility of the device. Therefore, this embodiment can achieve a lightweight design and realize excellent heat dissipation performance,

[0058] In one embodiment, the thickness of the phase-change thermal insulation layer 22 is 1 mm to 4 mm, and the size of the phase-change thermal insulation layer 22 is greater than or equal to the size of the battery stacking surface.

[0059] In this embodiment, the phase change insulation layer 22 is a component used to isolate and protect the battery stack, and its thickness ranges from 1 mm to 4 mm. The thickness of the phase change insulation layer 22 can be selected according to specific needs to provide appropriate insulation effect and protection performance. At the same time, the size of the phase change insulation layer 22 is greater than or equal to the size of the battery stacking surface, which means that the size of the phase change insulation layer 22 must be able to completely cover the surface of the battery stack. The purpose of this is to ensure that the phase change insulation layer 22 can effectively isolate and protect the entire battery stack from heat transfer and the influence of the external environment. By using a phase change insulation layer 22 of appropriate thickness and ensuring that its size can completely cover the battery stacking surface, the thermal insulation performance of the battery pack can be effectively improved, heat loss and temperature fluctuations can be reduced, thereby improving the efficiency and life of the battery pack.

[0060] In one embodiment, the thickness of the buffer foam layer 23 is 0.8 mm to 3 mm, and the outer contour size of the buffer foam is greater than or equal to the size of the battery stacking surface.

[0061] In this embodiment, the thickness of the buffer foam layer 23 ranges from 0.8 mm to 3 mm. The thickness of the buffer foam layer 23 can be selected according to specific needs to provide appropriate buffering effect and protective performance. At the same time, the outer contour size of the buffer foam layer 23 is greater than or equal to the size of the battery stacking surface, which means that the size of the buffer foam layer 23 must be able to completely cover the outer contour of the battery stack. The purpose of this is to ensure that the buffer foam layer 23 can effectively buffer and protect the entire battery stack and prevent the impact of collision and vibration on the battery pack. By using a buffer foam layer 23 of appropriate thickness and ensuring that its outer contour size can completely cover the battery stacking surface, the impact of collision and vibration on the battery pack can be effectively reduced, and the safety and stability of the battery pack can be protected. In addition, the buffer foam layer 23 can also provide additional insulation and anti-static protection to further improve the performance and reliability of the battery pack.

[0062] like Figure 5 As shown, in one embodiment, the fin layer 21 is provided on the stacking surface of one side of the battery cell 1, the stacking surface of the battery cell 1 away from the fin layer is attached to another battery cell 1, and the fin layers of every two battery cells 1 are arranged opposite to each other and the phase change insulation layer 22 and the buffer foam layer 23 are arranged between the fin layers of every two battery cells.

[0063] In this embodiment, the stacking surface of one side of the battery cell 1 is provided with the fin layer 21, and the stacking surface of the battery cell 1 away from the fin layer is attached to another battery cell 1, and the fin layers of every two battery cells 1 are arranged opposite to each other, and the phase change insulation layer 22 and the buffer foam layer 23 are arranged between the fin layers of every two battery cells. This means that a circular stack of "fin layer 21-battery cell 1-battery cell 1-fin layer 21-phase change insulation layer 22-buffer foam layer 23-fin layer 21" will be formed in the battery cell stack, which can make full use of the space in the battery cell stack to achieve a compact design, which helps to reduce the overall volume of the battery module, improve the energy density, and make it more suitable for use in limited space scenarios. At the same time, the heat dissipation surface area of ​​the fin layer is increased, the heat absorption and heat release of the phase change insulation layer, and the mechanical buffering and shock absorption effect of the buffer foam layer are improved, The heat dissipation effect, thermal balance and mechanical stability of the battery module are improved. This can effectively remove the generated heat, maintain the appropriate operating temperature of the battery cell, and improve the battery performance and life.

[0064] like Figure 6 As shown, in one embodiment, the buffer foam layer 23 is arranged between the two battery cells 1, and the fin layer 21 is arranged on the stacking surface of the battery cell 1 away from the buffer foam 23, and the phase change insulation layer 22 is arranged on the side of the fin layer 21 away from the battery cell 1.

[0065] In this embodiment, the buffer foam layer 23 is arranged between every two of the battery cells 1, and the fin layer 21 is arranged on the stacking surface of the battery cell 1 away from the buffer foam 23, and the phase change insulation layer 22 is arranged on the side of the fin layer 21 away from the battery cell 1. It is equivalent to stacking in the battery cell stack in the order of "battery cell 1-buffer foam layer 23-battery cell 1-phase change insulation layer 22", wherein the battery cells 1 on both sides of each phase change insulation layer are provided with fin layers 21, and the buffer foam layer 23 is located between the battery cells 1, providing space for battery expansion and having a certain heat insulation effect. This helps to prevent the battery cell 1 from being damaged due to expansion during operation, improves the mechanical stability and durability of the battery module, and the fin layer 21 is arranged on the battery cell stacking surface, which can increase the heat dissipation surface area and improve the heat dissipation efficiency. The phase change insulation layer 22 is arranged away from the side of the battery cell, so that the heat is more concentrated in the horizontal direction, thereby increasing the heat dispersion effect. Such a design helps to improve the thermal management effect of the entire battery module, reduce heat accumulation and temperature rise. The phase change insulation layer 22 is arranged close to the fin layer 21 and one side of the battery cell 1, which can absorb the heat generated by the thermal failure battery, reduce the temperature peak of the failed battery, and block the conduction of heat to other battery cells. This can effectively prevent the spread of thermal runaway and protect the safety of other battery cells. Through this embodiment, the buffer foam layer 23 is arranged on the stacking surface of one side of the battery cell 1, the fin layer 21 is arranged on the side of the battery cell 1 away from the buffer foam 23, and the phase change insulation layer 22 is arranged on the side of the fin layer 21 away from the battery cell. It can provide mechanical buffering and shock absorption effects, reduce the temperature peak of the thermal failure battery, and reduce the spread of thermal runaway. Such a design helps to improve the safety performance, heat dissipation efficiency and mechanical stability of the battery pack.

[0066] In one embodiment, a battery module is further provided, comprising: a plurality of battery cells 1 , wherein the plurality of battery cells 1 are stacked and arranged, and the multi-layer composite heat insulation structure is arranged between adjacent battery cells 1 .

[0067] In this embodiment, the battery module includes a plurality of battery cells 1, and a multi-layer composite thermal insulation structure 2 is arranged between the battery cells 1. The multi-layer composite thermal insulation structure 2 can solve the problem of thermal runaway transmission in the battery module, and can meet the requirements of thermal management system such as thermal conductivity and temperature uniformity, heat dissipation and cooling, reducing the peak temperature of the battery module, and providing battery expansion space during normal operation, and can also meet the requirements of thermal shock protection, heat dissipation, heat resistance, heat absorption, and heat insulation when the battery is thermally runaway, effectively preventing the propagation of thermal runaway between the battery cells inside the battery.

[0068] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-layer composite heat insulation structure, arranged between adjacent battery cells, characterized in that: It comprises a stacked fin layer, a phase-change heat-insulating layer and a buffer foam layer, wherein the fin layer is in contact with the stacking surface of the battery core; and the edge sealing of the phase-change heat-insulating layer is coated with a heat-resistant protective component.

2. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The phase-change heat-insulating layer comprises an insulating sealing layer, a flame-retardant phase-change material and a heat-insulating layer, wherein the insulating sealing layer is a hollow structure, a heat-insulating layer is arranged inside the insulating sealing layer and is filled with the flame-retardant phase-change material.

3. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The phase-change heat-insulating layer is arranged between the fin layer and the buffer foam layer, and is attached to a side of the fin layer away from the battery core.

4. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The buffer foam layer is arranged between the fin layer and the phase change insulation layer.

5. The multi-layer composite thermal insulation structure according to claim 4, characterized in that: The side of the phase change heat insulation layer close to the fin layer is coated with a heat-resistant protection component.

6. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The opposite sides of each fin layer extend along the stacking direction of the battery cells to form extended fins.

7. The multi-layer composite thermal insulation structure according to claim 6, characterized in that: An extension length of the extension fin is less than or equal to a thickness of the battery core.

8. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The thickness of the heat-resistant protection component ranges from 0.1 to 1 mm.

9. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The material of the fin layer is one of aluminum, copper, aluminum alloy or copper alloy, and the thickness is 0.1 mm to 0.6 mm.

10. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The thickness of the phase-change heat-insulating layer is 1 mm to 4 mm, and the size of the phase-change heat-insulating layer is greater than or equal to the size of the battery stacking surface.

11. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The thickness of the buffer foam layer is 0.8 mm to 3 mm, and the outer contour size of the buffer foam layer is greater than or equal to the size of the battery stacking surface.

12. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The fin layer is arranged on one stacking surface of the battery cell, the stacking surface of the battery cell away from the fin layer is bonded to another battery cell, and the fin layers of every two battery cells are arranged opposite to each other and the phase change insulation layer and the buffer foam layer are arranged between the fin layers of every two battery cells.

13. The multi-layer composite thermal insulation structure according to claim 1, characterized in that: The buffer foam layer is arranged on one stacking surface of the battery core, the fin layer is arranged on one stacking surface of the battery core away from the buffer foam, and the phase change heat insulation layer is arranged on one side of the fin layer away from the battery core.

14. A battery module, characterized in that: It comprises a plurality of battery cells, which are stacked and arranged, and a multi-layer composite thermal insulation structure as described in any one of claims 1 to 13 is arranged between adjacent battery cells.

Images