Composite heat insulation pad, battery and electric device

Abstract

The utility model relates to a composite heat insulation pad, a battery and an electric device. A composite heat insulation pad comprises a heat insulation pad body and a heat conduction layer, the heat conduction layer is arranged in the heat insulation pad body, and the thickness of the heat conduction layer tends to increase in the first direction from one end of the heat insulation pad body to the other end of the heat insulation pad body. According to the composite heat insulation pad, the heat insulation pad body can play a role in heat insulation, the heat conduction layer is arranged in the heat insulation pad body, and when heat is conducted into the heat insulation pad body and reaches the heat conduction layer, the heat conduction layer can quickly and uniformly disperse the heat to the periphery; therefore, heat is more easily gathered from the end with the smaller thickness of the heat conduction layer to the other end with the larger thickness of the heat conduction layer, so that part of heat can be directionally conducted to target positions such as an area capable of rapidly dissipating heat, and rapid and uniform heat dissipation is realized. The composite heat insulation pad has good heat insulation performance, is applied to the battery and has a good effect of preventing and slowing the thermal runaway of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a composite thermal insulation pad, a battery and an electrical device. Background Art

[0002] With the development of new energy technologies, batteries are increasingly used in the market. People's requirements for battery performance, such as energy density, are also getting higher and higher. However, battery cells with higher energy density have greater residual energy after thermal runaway. When a battery cell thermally runs away, its heat will continue to transfer from the battery cell to the adjacent battery cells, thereby causing heat diffusion of the entire battery and causing damage to the entire battery. Therefore, how to prevent or slow down battery thermal runaway is an urgent problem to be solved. Utility Model Content

[0003] Based on this, it is necessary to provide a composite thermal insulation pad, battery and electrical device to prevent or slow down the problem of battery thermal runaway.

[0004] In a first aspect, the present application provides a composite thermal insulation pad, comprising:

[0005] The insulation pad body; and

[0006] The heat-conducting layer is arranged inside the heat-insulating pad body, and the thickness of the heat-conducting layer increases in a first direction from one end to the other end of the heat-insulating pad body.

[0007] The composite thermal insulation pad mentioned above in the present application, on the one hand, the thermal insulation pad body can play a role of heat insulation, and on the other hand, a heat-conducting layer is arranged inside the thermal insulation pad body. When the heat is conducted to the inside of the thermal insulation pad body and reaches the thermal conductivity layer, the thermal conductivity layer can quickly and evenly disperse the heat to the surroundings, thereby playing a role of rapid heat dissipation. In particular, due to the specific thickness setting of the thermal conductivity layer, the heat is more likely to gather from the end of the thermal conductivity layer with a smaller thickness to the other end with a larger thickness, which is conducive to the directional conduction of part of the heat to the target position such as the area where rapid heat dissipation can be achieved, thereby achieving rapid and uniform heat dissipation. The composite thermal insulation pad is applied to the battery. When the battery is in normal working condition, the thermal insulation pad body mainly plays a role of heat insulation. When the battery heats up abnormally, the thermal conductivity layer can play a role of rapid and uniform diffusion, thereby having the effect of preventing or slowing down the thermal runaway of the battery.

[0008] In any embodiment of the present application, the thermal conductive layer includes at least one of a metal layer and a graphene film layer.

[0009] In any embodiment of the present application, the thickness of the heat conductive layer gradually increases in the first direction.

[0010] In any embodiment of the present application, the composite thermal insulation pad satisfies at least one of the following conditions:

[0011] (1) The dimension of the heat conductive layer in the first direction is 80 mm to 400 mm;

[0012] (2) The thermal conductive layer includes a first end with a smaller thickness and a second end with a larger thickness in the first direction. The thickness of the first end is 0-0.02 mm, and the thickness of the second end is 0.03 mm-0.05 mm.

[0013] In any embodiment of the present application, the cross-sectional shape of the heat-conducting layer in the thickness direction of the composite thermal insulation pad includes one of a triangle and a trapezoid.

[0014] In any embodiment of the present application, the thermal insulation pad body includes a first thermal insulation layer, a phase change material layer, and a second thermal insulation layer stacked in sequence, and the thermal conductive layer is disposed within the phase change material layer.

[0015] In any embodiment of the present application, the phase change material layer includes a heat insulation substrate and a phase change material, the phase change material is filled in the heat insulation substrate, and the heat conductive layer is disposed in the heat insulation substrate.

[0016] In any embodiment of the present application, the cross-sectional shape of the phase change material layer and the composite thermal insulation pad in the thickness direction of the composite thermal insulation pad is rectangular.

[0017] In any embodiment of the present application, the composite thermal insulation pad satisfies at least one of the following conditions:

[0018] (1) The thickness of the first thermal insulation layer is 0.5 mm to 8 mm;

[0019] (2) The thickness of the phase change material layer is 0.1 mm to 6 mm;

[0020] (3) The thickness of the second thermal insulation layer is 0.5 mm to 8 mm.

[0021] In any embodiment of the present application, the composite thermal insulation pad satisfies at least one of the following conditions:

[0022] (1) The composite thermal insulation pad further includes a first encapsulation layer, which is disposed on the outer peripheral side of the phase change material layer and encapsulates the phase change material layer;

[0023] (2) The composite thermal insulation pad further includes a second packaging layer, which is disposed on the outer peripheral side of the first thermal insulation layer and packages the first thermal insulation layer;

[0024] (3) The composite thermal insulation pad further includes a third packaging layer, which is disposed on the outer peripheral side of the second thermal insulation layer and packages the second thermal insulation layer.

[0025] In any embodiment of the present application, the composite thermal insulation pad satisfies at least one of the following conditions:

[0026] (1) The first encapsulation layer, the second encapsulation layer and the third encapsulation layer are each independently an aluminum-plastic film or a polymer encapsulation film;

[0027] (2) The thickness of the first encapsulation layer, the second encapsulation layer, and the third encapsulation layer are each independently 0.1 mm to 0.3 mm.

[0028] In any embodiment of the present application, the edges of the first heat insulation layer and the second heat insulation layer cooperate with each other to form an assembly cavity, and the phase change material layer is located in the assembly cavity.

[0029] In any embodiment of the present application, an edge of at least one side surface of at least one of the first thermal insulation layer and the second thermal insulation layer forms a convex portion, and the convex portion encloses and forms at least a portion of the assembly cavity.

[0030] In any embodiment of the present application, the composite thermal insulation pad further includes a first packaging frame and a second packaging frame, and the first packaging frame cooperates with the second packaging frame to fix the thermal insulation pad body provided with the thermal conductive layer.

[0031] In any embodiment of the present application, the first packaging frame has a first limiting groove, the second packaging frame has a second limiting groove, and the thermal insulation pad body provided with the thermal conductive layer is limited in the limiting space formed by the first limiting groove and the second limiting groove.

[0032] In a second aspect, the present application provides a battery, comprising a battery cell and a composite thermal insulation pad as provided in the first aspect of the present application, wherein the composite thermal insulation pad is arranged adjacent to the battery cell.

[0033] In any embodiment of the present application, the battery cell includes a shell and an explosion-proof valve, the explosion-proof valve is arranged on one side of the shell, and the composite thermal insulation pad is arranged close to the explosion-proof valve at the end where the thermal conductive layer is thinner.

[0034] In any embodiment of the present application, the battery further includes a heat dissipation component, and the composite thermal insulation pad is disposed close to the heat dissipation component with the end of the thermal conductive layer having a thicker thickness.

[0035] In any embodiment of the present application, the battery further includes a plurality of the battery cells, and the composite thermal insulation pad is provided between at least two adjacent battery cells.

[0036] In any embodiment of the present application, the composite thermal insulation pad is arranged between at least two adjacent large surfaces of the battery cells.

[0037] In a third aspect, the present application provides an electrical device, comprising the battery provided in the second aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to one embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0041] Figure 4 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0042] Figure 5 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0043] Figure 6 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0044] Figure 7 This is a schematic diagram of the three-dimensional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0045] Figure 8 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0046] Fig. 9 This is a schematic diagram of the structure of a battery according to one embodiment of the present application;

[0047] Fig.10 This is a schematic diagram of the exploded structure of a battery according to one embodiment of the present application;

[0048] Fig.11 is a schematic structural diagram of a battery cell in a battery according to an embodiment;

[0049] Fig.12 A schematic diagram of the structure of a battery according to another embodiment of the present application;

[0050] Fig.13 A schematic diagram of an electrical device using a battery as a power source according to an embodiment of the present application;

[0051] Fig.14 The thermal insulation performance curve diagram of the composite thermal insulation pad prepared in Example 1 and Comparative Example 1.

[0052] Description of reference numerals:

[0053] 10. Composite thermal insulation pad; 11. Thermal insulation pad body; 111. First thermal insulation layer; 112. Second thermal insulation layer; 113. Phase change material layer; 12. Thermal conductive layer; 131. First encapsulation layer; 132. Second encapsulation layer; 133. Third encapsulation layer; 141. First encapsulation frame; 142. Second encapsulation frame; 151. First adhesive layer; 152. Second adhesive layer;

[0054] 20. Battery cell; 21. Shell; 22. Electrode assembly; 23. Cover plate; 24. Explosion-proof valve;

[0055] 30. Battery; 32. Heat dissipation component;

[0056] 40. Electrical equipment. DETAILED DESCRIPTION

[0057] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0058] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 application.

[0059] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0060] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0062] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0063] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries, especially power batteries, are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0064] A battery cell is the smallest unit that makes up a battery. A battery may include one or more battery cells, and multiple battery cells may be connected in series, in parallel, or in a hybrid connection. Among them, a hybrid connection means that multiple battery cells are connected in both series and in parallel.

[0065] After multiple battery cells are connected to each other and arranged in a certain order, they can be directly placed in a box to assemble into a battery. Alternatively, multiple battery cells can be first assembled into a battery module, and then multiple battery modules are connected to each other to form a whole, and finally the whole battery module is placed in a box to form a battery.

[0066] In order to solve the above-mentioned battery thermal runaway problem and reduce the damage and risk to the entire battery.

[0067] See also Figure 1 In one embodiment of the present application, a composite thermal insulation pad 10 is provided, comprising a thermal insulation pad body 11 and a thermal conductive layer 12. The thermal conductive layer 12 is disposed within the thermal insulation pad body 11, and the thickness of the thermal conductive layer 12 increases in a first direction from one end to the other end of the thermal insulation pad body 11.

[0068] It can be understood that the first direction is located in a plane perpendicular to the thickness direction of the thermal insulation pad body 11. In other words, the thickness of the thermal conductive layer 12 increases from one end to the other end of the plane. Figure 1 In the example of FIG. 1 , the thickness of the heat conducting layer 12 increases from top to bottom.

[0069] It is understandable that the thickness of the heat conductive layer 12 increases in the first direction, including but not limited to the thickness of the heat conductive layer 12 gradually increasing in the first direction (i.e., continuously increasing) or discontinuously increasing (e.g., increasing as a whole but with a portion of constant thickness).

[0070] The composite thermal insulation pad 10 mentioned above in the present application, on the one hand, the thermal insulation pad body 11 can play a role of heat insulation, and on the other hand, a heat-conducting layer 12 is arranged inside the thermal insulation pad body 11. When the heat is conducted to the inside of the thermal insulation pad body 11 and reaches the thermal conductivity layer 12, the thermal conductivity layer 12 can quickly and evenly disperse the heat to the surroundings, thereby playing a role of rapid heat dissipation. In particular, due to the specific thickness setting of the thermal conductivity layer 12, the heat is more easily gathered from the end of the thermal conductivity layer 12 with a smaller thickness to the other end with a larger thickness, which is conducive to the directional conduction of part of the heat to the target position such as the area where rapid heat dissipation can be achieved, thereby achieving rapid and uniform heat dissipation. The composite thermal insulation pad 10 is applied to batteries. When the battery is in normal working condition, the thermal insulation pad body 11 mainly plays a role of heat insulation. When the battery heats up abnormally, the thermal conductivity layer 12 can play a role of rapid and uniform diffusion, thereby having the effect of preventing or slowing down the thermal runaway of the battery.

[0071] In some embodiments of the present application, the heat conducting layer 12 includes at least one of a metal layer and a graphene film layer. In some examples, the heat conducting layer 12 includes a stack of one or both of the metal layer and the graphene film layer. In some embodiments, the metal layer includes but is not limited to a pure metal layer or an alloy layer of at least one of copper, aluminum and iron. As an example, the metal layer is a copper metal layer or an aluminum metal layer. Among them, the copper metal layer has a better effect of suppressing thermal radiation.

[0072] In some embodiments of the present application, the thickness of the heat-conducting layer 12 gradually increases in the first direction. In this way, heat is more easily gathered from one end of the heat-conducting layer 12 with a smaller thickness to the other end with an increased thickness, thereby facilitating the directional conduction of part of the heat to a target location such as an area where heat can be quickly dissipated.

[0073] Further, the size of the heat-conducting layer 12 in the first direction is 80mm~400mm. As an example, the size of the heat-conducting layer 12 in the first direction is 80mm, 90mm, 100mm, 120mm, 140mm, 150mm, 160mm, 180mm, 200mm, 210mm, 250mm, 300mm, 350mm, 400mm; further, it can be 80mm~210mm, or within the range formed by any two of the above point values ​​as end values, and the following is similar. It can be understood that the size of the heat-conducting layer 12 in the first direction can be based on the size of the insulation pad body or the object it is aimed at, such as a battery, in this direction.

[0074] Further, the heat-conducting layer 12 includes a first end with a smaller thickness and a second end with a larger thickness in the first direction, the thickness of the first end is 0-0.02 mm, and the thickness of the second end is 0.03 mm-0.05 mm. It can be understood that the thickness of the first end is 0, which means that the thickness at this position is close to or equal to 0. For example, the cross-sectional shape of the heat-conducting layer 12 in the thickness direction is a triangle, and the first end is a vertex of the triangle.

[0075] As an example, the thickness of the first end may be 0, 0.01 mm, 0.02 mm. As an example, the thickness of the second end may be 0.03 mm, 0.04 mm, 0.05 mm.

[0076] Furthermore, the thickness of the first end of the heat conducting layer 12 is 0.01 mm to 0.02 mm, and the thickness of the second end is 0.03 mm to 0.05 mm.

[0077] In some embodiments of the present application, the cross-sectional shape of the heat-conducting layer 12 in the thickness direction of the composite thermal insulation pad 10 includes one of a triangle and a trapezoid.

[0078] Further, the cross-sectional shape is a triangle, the end of the heat-conducting layer 12 with a smaller thickness in the first direction is a vertex of the triangle, and the end with a larger thickness is a side of the triangle. Further, the triangle includes one of a right triangle, an acute triangle, and an obtuse triangle. Further, the cross-sectional shape can be one of a right triangle and an isosceles triangle.

[0079] Further, the cross-sectional shape is a trapezoid, the end of the heat conductive layer 12 with a smaller thickness in the first direction is the shorter base of the trapezoid, and the end of the heat conductive layer 12 with a larger thickness in the first direction is the longer base of the trapezoid. As an example, the trapezoid includes one of a right-angled trapezoid and an isosceles trapezoid.

[0080] For example, in Figure 1 In the example shown, the cross-sectional shape of the heat-conducting layer 12 in the thickness direction of the composite thermal insulation pad 10 is a triangle, specifically an isosceles triangle. Figure 2 In the example shown, the cross-sectional shape of the heat-conducting layer 12 in the thickness direction of the composite thermal insulation pad 10 is a trapezoid, specifically an isosceles trapezoid.

[0081] See also Figure 1 and Figure 2 In some embodiments of the present application, the thermal insulation pad body 11 includes a first thermal insulation layer 111 and a second thermal insulation layer 112 stacked in sequence. The thermal conductive layer 12 is disposed between the first thermal insulation layer 111 and the second thermal insulation layer 112.

[0082] See also Figure 3In some embodiments of the present application, the thermal insulation pad body 11 includes a first thermal insulation layer 111, a phase change material layer 113, and a second thermal insulation layer 112, which are stacked in sequence. In this way, when one side of the composite thermal insulation pad 10 is in contact with or close to a heat source, the first thermal insulation layer 111 or the second thermal insulation layer 112 of the thermal insulation pad body 11 first acts as a heat insulator. When heat is transferred to the phase change material layer 113 on this side, the phase change material layer 113 absorbs heat and undergoes a phase change, which cools down the composite thermal insulation pad 10 as a whole and can also slow down its further diffusion. When heat is transferred to the thermal conductive layer 12 in the thermal insulation pad body 11, the thermal conductive layer 12 can quickly transfer heat and dissipate heat quickly.

[0083] Furthermore, the heat-conducting layer 12 is disposed within the phase-change material layer 113. When the heat is further conducted to the heat-conducting layer 12 disposed in the phase-change material layer 113, the heat diffuses rapidly along the surface of the heat-conducting layer 12. On the one hand, the heat-conducting effect of the heat-conducting layer 12 can trigger the phase-change of a larger area of ​​the phase-change material layer 113 and absorb heat and cool down. On the other hand, the heat can be diffused to the surroundings, especially to the end with a larger thickness, thereby further improving the heat-insulating effect of the composite thermal insulation pad 10.

[0084] In some embodiments of the present application, the cross-sectional shape of the phase change material layer 113 and the composite thermal insulation pad 10 in the thickness direction of the composite thermal insulation pad 10 is rectangular. In some embodiments of the present application, the overall thickness of the phase change material layer 113 and the composite thermal insulation pad 10 is constant in the first direction.

[0085] In some embodiments of the present application, the thickness of the first heat insulating layer 111 is 0.5 mm to 8 mm. As an example, it can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm; it can be 1 mm to 8 mm.

[0086] In this article, the following method can be used to test the thickness of the composite thermal insulation pad. The equipment used is: Mitutoyo 547-301 thickness gauge, equipment accuracy: ≤0.01mm; during the test, the test surface of the composite thermal insulation pad and Mitutoyo 547-301 thickness gauge are required to be parallel to the ground, and the test positions are 5 points in the four corners and the center area, and the average value of the 5 points is taken as the test value.

[0087] In some embodiments of the present application, the thickness of the second heat insulating layer 112 is 0.5 mm to 8 mm. As an example, it can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm; it can be 1 mm to 8 mm.

[0088] In some embodiments of the present application, the thickness of the phase change material layer 113 is 0.1mm~6mm; it can be 1mm~4mm; as an example, it can be 0.1mm, 0.2mm, 0.4mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 5mm, 6mm; it can also be 1.5mm~3.5mm.

[0089] See also Figure 4 In some embodiments of the present application, the composite thermal insulation pad 10 also includes at least one of a first encapsulation layer 131 , a second encapsulation layer 132 , and a third encapsulation layer 133 .

[0090] The first encapsulation layer 131 is disposed on the outer peripheral side of the phase change material layer 113 and encapsulates the phase change material layer 113. The phase change material of the phase change material layer 113 will undergo a phase change. For example, a solid phase change material at room temperature will turn into a liquid state after absorbing heat. Therefore, the first encapsulation layer 131 can also play a role in isolating the phase change material in a liquid state after the phase change from the thermal insulation pad body 11. In addition, some preparation processes inevitably cause the phase change material to carry moisture. Using the first encapsulation layer 131 to encapsulate the phase change material layer 113 can prevent moisture overflow from causing adverse effects on the battery.

[0091] The second encapsulation layer 132 is disposed on the outer peripheral side of the first thermal insulation layer 111 and encapsulates the first thermal insulation layer 111. The third encapsulation layer 133 is disposed on the outer peripheral side of the second thermal insulation layer 112 and encapsulates the second thermal insulation layer 112. The second encapsulation layer 132 and the third encapsulation layer 133 can be used to protect the thermal insulation layers therein from contamination and damage.

[0092] In some examples, each of the above-mentioned packaging layers can be formed by packaging two packaging films, for example, by packaging by edge pressing or edge wrapping, so that a packaging margin is provided at the edge of each packaging layer. Further, the packaging margin is pressed between two adjacent film layers.

[0093] exist Figure 4 In the specific example shown, the first encapsulation layer 131, the second encapsulation layer 132 and the third encapsulation layer 133 are included. Figure 5 In the specific example shown, only the first encapsulation layer 131 mentioned above is included.

[0094] In some embodiments, the first encapsulation layer 131 , the second encapsulation layer 132 , and the third encapsulation layer 133 are each independently an aluminum-plastic film or a polymer encapsulation film.

[0095] Furthermore, the aluminum-plastic film includes a polypropylene layer, an aluminum layer and a nylon layer stacked from inside to outside.

[0096] Furthermore, the polymer packaging film may be a PET film (polyethylene terephthalate film) or a PI film (polyimide film).

[0097] Furthermore, the first encapsulation layer 131 is an aluminum-plastic film. Because the aluminum-plastic film has better strength, it is used to encapsulate the phase change material layer 113 that undergoes phase change, and can play a better role in insulating the phase change material layer 113 and the outer insulation layer. The second encapsulation layer 132 and the third encapsulation layer 133 are polymer encapsulation films; the outer insulation layer uses a polymer encapsulation film to achieve good protection of the insulation layer.

[0098] Furthermore, the thickness of the first encapsulation layer 131, the second encapsulation layer 132 and the third encapsulation layer 133 are independently 0.1 mm to 0.3 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, and can be 0.1 mm to 0.15 mm, or 0.2 mm to 0.3 mm.

[0099] See also Figure 6 In some embodiments, the edges of the first thermal insulation layer 111 and the second thermal insulation layer 112 are connected to each other to form an assembly cavity, and the heat-conducting layer 12 is located in the assembly cavity. With this structural setting, the heat-conducting layer 12 is arranged inside the first thermal insulation layer 111 and the second thermal insulation layer 112, reducing the risk of the heat-conducting layer 12 falling off. Furthermore, the phase change material layer 113 is also located in the assembly cavity.

[0100] Further, the edge of at least one side surface of at least one of the first thermal insulation layer 111 and the second thermal insulation layer 112 forms a convex portion, and the convex portion encloses at least part of the assembly cavity. As an example, the edge of at least one side surface of the first thermal insulation layer 111 and the second thermal insulation layer 112 forms a convex portion, and the convex portions of the two are arranged relative to each other and enclose to form an assembly cavity. In a specific example, the edges of the four sides of the surface of one side of the first thermal insulation layer 111 and the second thermal insulation layer 112 form a convex portion, and the convex portions of the first thermal insulation layer 111 and the second thermal insulation layer 112 are arranged relative to each other and enclose to form an assembly cavity.

[0101] See also Figure 7 In some of the embodiments, the composite thermal insulation pad 10 further includes a first packaging frame 141 and a second packaging frame 142 , and the first packaging frame 141 and the second packaging frame 142 cooperate to fix the thermal insulation pad body 11 having the heat-conducting layer 12 therein.

[0102] Furthermore, the first packaging frame 141 is disposed on one side of the first insulation layer 111 , and the second packaging frame 142 is disposed on one side of the second insulation layer 112 . The first packaging frame 141 and the second packaging frame 142 cooperate to fix the insulation pad body 11 with the heat-conducting layer 12 disposed therein.

[0103] Further, the first packaging frame 141 and the second packaging frame 142 are each independently a rubber frame or a silicone frame, which has good flexibility and can absorb the expansion force caused by the expansion of the battery. In other words, the material of the first packaging frame 141 and the second packaging frame 142 is each independently rubber or silicone. Further, the first packaging frame 141 and the second packaging frame 142 are each independently a mouth-shaped frame, such as a mouth-shaped silicone frame.

[0104] Furthermore, the first packaging frame 141 has a first limiting groove (not shown), and the second packaging frame 142 has a second limiting groove (not shown), and the thermal insulation pad body 11 with the thermal conductive layer 12 disposed therein is limited in the limiting space formed by the first limiting groove and the second limiting groove. The first limiting groove and the second limiting groove can limit the thermal insulation pad body 11 with the thermal conductive layer 12 disposed therein in the thickness direction and radial direction of the composite thermal insulation pad 10, thereby improving the structural stability of the composite thermal insulation pad 10.

[0105] The radial direction of the composite thermal insulation pad 10 refers to the direction from the center of the composite thermal insulation pad 10 to the edge of the composite thermal insulation pad 10. Furthermore, the package margin of the third package layer can be located between the first package frame 141 and the second package frame 142, and can be pressed by the side walls of the first package frame 141 and the second package frame 142, and can also play a fixing role. Alternatively, the package margin of the third package layer can also be folded and located in the assembly cavity.

[0106] It can be understood that when the above-mentioned first packaging frame 141 and second packaging frame 142 and the above-mentioned first thermal insulation layer 111 and second thermal insulation layer 112 capable of forming an assembly cavity are provided at the same time, the packaging margin portion of the third packaging layer can pass through between the convex portions of the first thermal insulation layer 111 and the second thermal insulation layer 112 and be located between the first packaging frame 141 and the second packaging frame 142. Alternatively, the packaging margin portion of the third packaging layer can also be folded and located in the assembly cavity.

[0107] In other embodiments, the outer surface of the first thermal insulation layer 111 is flush with the outer surface of the first packaging frame 141, and / or the outer surface of the second thermal insulation layer 112 is flush with the outer surface of the second packaging frame 142. In this way, the thickness of the composite thermal insulation pad 10 can be minimized, the space it occupies can be reduced, and better thermal insulation performance can be provided.

[0108] See also Figure 8In some embodiments, the composite thermal insulation pad 10 further includes an adhesive layer, and at least one of the first thermal insulation layer 111 and the second thermal insulation layer 112 is connected to the thermal conductive layer 12 through the adhesive layer. Further, the adhesive layer includes a first adhesive layer 151 and a second adhesive layer 152. The first thermal insulation layer 111 is connected to the thermal conductive layer 12 through the first adhesive layer 151; the second thermal insulation layer 112 is connected to the thermal conductive layer 12 through the second adhesive layer 152. In this way, the first thermal insulation layer 111, the thermal conductive layer 12 and the second thermal insulation layer 112 of the composite thermal insulation pad 10 are connected and fixed in the thickness direction through the adhesive layer.

[0109] Furthermore, in Figure 8 In the specific example shown, when the heat conductive layer 12 is disposed in the phase change material layer 113 , the first adhesive layer 151 and the second adhesive layer 152 respectively bond the first heat insulating layer 111 and the second heat insulating layer 112 to opposite surfaces of the phase change material layer 113 .

[0110] Furthermore, the material of the first adhesive layer 151 and the second adhesive layer 152 are each independently a silicone adhesive layer, and the thickness is independently 0.04-0.06 mm. The silicone adhesive layer is resistant to high temperatures and has high structural strength. The peeling force of the prepared composite thermal insulation pad is greater than 10N / cm. The peeling force can be measured by pulling the two sides of the composite thermal insulation pad with a tensile gauge, and applying a force perpendicular to the composite thermal insulation pad at 90° to the two sides of the composite thermal insulation pad. The tensile gauge will display the magnitude of the pulling force when the composite thermal insulation pad is peeled off, and the peeling force is obtained based on the magnitude of the pulling force.

[0111] In some embodiments, the composite thermal insulation pad 10 may further include a third thermal insulation layer (not shown), the third thermal insulation layer and the second thermal insulation layer 112 are stacked, and a thermal conductive layer 12 is also provided between the second thermal insulation layer 112 and the third thermal insulation layer. Furthermore, the composite thermal insulation pad 10 may further include more thermal insulation layers, and the above-mentioned thermal conductive layer 12 may also be provided between the third thermal insulation layer and the adjacent thermal insulation layer.

[0112] Furthermore, the selection range of materials and thicknesses of the third thermal insulation layer and other thermal insulation layers may be the same as that of the first thermal insulation layer 111 and the second thermal insulation layer 112; the specific materials and specific thicknesses may be the same or different.

[0113] In some embodiments, the composite thermal insulation pad 10 further includes a release adhesive layer (not shown). The release adhesive layer includes a release film and a third adhesive layer disposed on the release film, the third adhesive layer being disposed on the outer surface of the thermal insulation pad body 11, such as the outer surface of the first thermal insulation layer 111 and / or the second thermal insulation layer 112, and the release film being disposed on the outer surface of the third adhesive layer. In this way, when the composite thermal insulation pad 10 needs to be fixed at a target position, such as a target battery cell, the release film on the surface of the release adhesive layer on the composite thermal insulation pad 10 is removed, and it is simply and conveniently fixed to the target position by bonding with the third adhesive layer, which can play the role of fixing the composite thermal insulation pad 10.

[0114] As an example, the above-mentioned release adhesive layer is provided on the outer surfaces of the first insulation layer 111 and the second insulation layer 112 of the composite insulation pad 10. When in use, the composite insulation pad 10 can be bonded and fixed to two objects respectively through the release adhesive layers on both sides, for example, bonded and fixed to two adjacent battery cells respectively, so that the composite insulation pad 10 is arranged between the two adjacent battery cells.

[0115] As an example, on the basis of the first adhesive layer 151 and the second adhesive layer 152, the first packaging frame 141 and the second packaging frame 142 can be further used to fix the four sides of the thermal insulation pad body 11, thereby improving the structural stability of the composite thermal insulation pad 10. Furthermore, at this time, there is no need for the packaging frame to fix the thickness direction, so the outer surface of the first thermal insulation layer 111 can be flush with the outer surface of the first packaging frame 141, and the outer surface of the second thermal insulation layer 112 can be flush with the outer surface of the second packaging frame 142.

[0116] It can be understood that in some embodiments, the first thermal insulation layer 111, the thermal conductive layer 12, the second thermal insulation layer 112, and the third thermal insulation layer can be connected by the above-mentioned adhesive layer instead of the above-mentioned packaging frame, or connected by the above-mentioned packaging frame instead of the above-mentioned adhesive layer, or connected by both the above-mentioned adhesive layer and the packaging frame, or none of them, for example, the first thermal insulation layer 111 can be directly formed on the surface of the thermal conductive layer 12 in the form of a coating.

[0117] Furthermore, the first thermal insulation layer 111, the second thermal insulation layer 112 and the third thermal insulation layer each independently include at least one of thermal insulation felt and thermal insulation coating.

[0118] Furthermore, when any of the above-mentioned thermal insulation layers includes both thermal insulation felt and thermal insulation coating, the thermal insulation coating may be optionally disposed on a side closer to the thermal conductive layer 12, specifically, the thermal insulation coating is disposed on the surface of the first encapsulation layer 131 of the thermal conductive layer 12, and the thermal insulation felt is disposed on a side further away from the thermal conductive layer 12. In other words, the thermal insulation coating is directly formed on the surface of the first encapsulation layer 131, and the thermal insulation coating is located between the first encapsulation layer 131 and the thermal insulation felt.

[0119] For example, Figure 6 In the example, the first thermal insulation layer 111 and the second thermal insulation layer 112 are thermal insulation felt, and the third thermal insulation layer is also thermal insulation felt. In other examples, the first thermal insulation layer 111 and the second thermal insulation layer 112 may also be thermal insulation coatings. In comparison, the thickness of the thermal insulation coating is thinner, the overall thickness of the prepared composite thermal insulation pad is thinner, and the required space is relatively smaller. The thermal insulation layer of the composite thermal insulation pad 10 can optionally adopt a thermal insulation coating, or a composite of a thermal insulation coating and ceramic felt, which can take into account both a smaller occupied space and better thermal insulation performance.

[0120] For example, in Figure 6 In the example shown, the first thermal insulation layer 111 and the second thermal insulation layer 112 are thermal insulation felts, and the assembly cavity thereon can be integrally formed when the thermal insulation felt is formed, or can be formed by grooving after the thermal insulation felt is formed.

[0121] It is understood that the thermal insulation felt can be connected to the thermal conductive layer 12 through the above-mentioned adhesive layer or packaging frame. The thermal insulation coating can be directly formed on the first packaging layer 131 in the thermal conductive layer 12. As an example, the thermal insulation coating can be prepared by coating the first packaging layer 131 of the thermal conductive layer 12 with a slurry and then drying it to form a coating.

[0122] Furthermore, the thermal insulation felt may be a ceramic thermal insulation felt; further, the thermal insulation coating may be a ceramic thermal insulation coating. It is understood that the ceramic thermal insulation felt and the ceramic thermal insulation coating are both ceramic material layers. In some embodiments, the thermal insulation pad body 11 is a ceramic material layer. In other words, the first thermal insulation layer 111, the second thermal insulation layer 112 and the third thermal insulation layer are each independently a ceramic material layer.

[0123] The material in the "ceramic material layer" in the present application includes but is not limited to at least one of ceramic oxides, ceramic nitrides, and ceramic carbides. Among them, ceramic oxides include but are not limited to at least one of silicon oxide and aluminum oxide, ceramic nitrides include but are not limited to silicon nitride, and ceramic carbides include but are not limited to silicon carbide.

[0124] In some examples, the ceramic material layer may be a stack of one or more of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, and a silicon carbide layer.

[0125] Furthermore, the ceramic insulation felt may be a silica aerogel ceramic felt. As an example, the silica aerogel ceramic felt may be prepared by inorganic fiber reinforcement technology to prepare aerogel materials, through impregnation sol, gel, solvent replacement and supercritical drying processes.

[0126] In some embodiments, the first thermal insulation layer 111, the second thermal insulation layer 112 and other thermal insulation layers independently meet the following conditions: thermal conductivity at 25°C ≤ 0.020 W / m·K, thermal conductivity at 200°C ≤ 0.027 W / m·K, thermal conductivity at 300°C ≤ 0.035 W / m·K, and thermal conductivity at 500°C ≤ 0.080 W / m·K. The test steps of thermal conductivity are as follows: cut the sample into a size of 300mm*300mm, stack it to a thickness that meets the minimum thickness requirement of 6mm for the test; put the sample into a thermal conductivity meter, set different temperatures, and measure the thermal conductivity of the sample at different temperatures.

[0127] In some embodiments, the density of the first thermal insulation layer 111, the second thermal insulation layer 112 and the other thermal insulation layers are independently 0.2-0.22 g / cm3 .

[0128] In some embodiments of the present application, the material of the phase change material layer 113 may be a pure phase change material.

[0129] In some embodiments of the present application, the phase change material layer 113 includes a heat insulating substrate in addition to the phase change material. Specifically, the phase change material layer 113 includes a heat insulating substrate and a phase change material, and the phase change material is filled in the pores in the heat insulating substrate. Further, the heat conductive layer 12 is disposed in the heat insulating substrate.

[0130] Furthermore, the phase change material layer 113 may be a solid, liquid or semi-solid phase change material. Optionally, the material of the phase change material layer 113 includes but is not limited to crystalline hydrated salt, phase change molten salt, paraffin, silicone oil, silica sol, aluminum sol, silica aluminum sol, fatty acid, alcohols and other substances that can undergo phase change and absorb heat, and its application range is wider, so it can provide better thermal insulation performance. Furthermore, the crystalline hydrated salt includes but is not limited to at least one of sodium carbonate and calcium chloride crystalline hydrated salt, such as sodium carbonate decahydrate (Na 2 CO 3 10H 2 O) and calcium chloride hexahydrate (CaCl 2 6H 2 O) at least one of the following. The aluminum sol includes aluminum hydroxide sol.

[0131] The thermal insulation substrate may be a ceramic material substrate, such as ceramic fiber felt.

[0132] Furthermore, in some examples, at least part of the phase change material is directly filled in the pores of the thermal insulation substrate. In other examples, the phase change material can also be filled in the pores of the thermal insulation substrate in the form of phase change microcapsules. It is understood that in the same thermal insulation substrate, two states of phase change materials can also be included at the same time, one is that the phase change material is directly filled in the pores of the thermal insulation substrate, and the other is that the phase change material is filled in the pores of the thermal insulation substrate in the form of phase change microcapsules.

[0133] It can be understood that a phase change material layer can be obtained by soaking a porous thermal insulation substrate such as ceramic fiber felt in a liquid phase change material, for example, soaking in a molten phase change material and then cooling it or soaking it in a phase change material solution and then drying or heat-insulating it. In addition to absorbing heat, the phase change material layer 113 can also play a role in heat insulation. When the phase change material vaporizes and breaks the first packaging layer 131, that is, the composite thermal insulation pad fails, the thermal insulation substrate in the phase change material layer 113 can continue to play a role in heat insulation. In other words, the phase change material is directly filled in the pores of the thermal insulation substrate.

[0134] In other embodiments, at least part of the phase change material is filled in the pores of the thermal insulation substrate in the form of phase change microcapsules. In other words, the pores of the thermal insulation substrate of the phase change material layer 113 can be filled with phase change microcapsules. The phase change microcapsules include a core material and a wall material, the wall material is wrapped around the outer surface of the core material, and the core material includes a phase change material. It can be understood that in some examples, the pores of the thermal insulation substrate can also be directly filled with phase change materials and the above-mentioned phase change microcapsules at the same time.

[0135] The above-mentioned phase change material layer 113 can be obtained by dispersing phase change microcapsules in a solvent to obtain a phase change microcapsule dispersion, then immersing a thermal insulation substrate in the phase change microcapsule dispersion to fill the phase change microcapsules in the pores of the thermal insulation substrate, and removing the solvent in the phase change microcapsule dispersion.

[0136] In this way, the phase change microcapsules in the phase change material layer 113 absorb heat. When the battery cell thermally runs away, the phase change material in the adjacent composite thermal insulation pad vaporizes and breaks the first packaging layer 131, that is, the composite thermal insulation pad 10 fails. At this time, the thermal insulation substrate in the phase change material layer 113 can continue to play a thermal insulation role.

[0137] Further, the wall material includes a polymer matrix and ceramic particles filled in the polymer matrix. Further, the mass ratio of the polymer matrix to the ceramic particles is 3:(7-11), and as an example, the mass ratio of the polymer matrix to the ceramic particles can be 3:7, 3:8, 3:9, 3:10, 3:11. By controlling the mass content of the ceramic particles in the wall material to be larger, the pressure resistance and heat insulation capacity of the wall material can be improved.

[0138] Furthermore, the mass ratio of the polymer matrix to the core material is 1:(1.3-1.6). As an example, the mass ratio of the polymer matrix to the core material can be 1:1.3, 1:1.4, 1:1.5, 1:1.6. This can further improve the pressure resistance of the phase change microcapsule.

[0139] Furthermore, the polymer matrix includes but is not limited to any one of phenolic resin, polyacrylonitrile resin, melamine formaldehyde resin, etc. The polymer matrix not only has good insulation, but also has good compatibility with phase change materials such as paraffin wax, can form a stable interface with the phase change material, and improve the thermal stability of the phase change microcapsules.

[0140] Furthermore, the Dv50 particle size of the phase change microcapsule is 5 to 8 μm. The Dv50 particle size is the volume average particle size Dv50, which indicates the particle size corresponding to when the cumulative volume distribution percentage of the particles reaches 50%, and can be tested by methods known in the art. For example, it can be measured using a laser particle size analyzer (such as Malvern Master Size 3000).

[0141] Furthermore, the thermal conductivity of the wall material at 25° C. is ≥ 0.32 W / m·K. Such a wall material has a good thermal conductivity and can better conduct heat to the phase change material inside it.

[0142] Furthermore, the melting point of the wall material is greater than 98° C. The wall material has a relatively high melting point, and can maintain the structural stability of the microcapsule within the phase change temperature range of the phase change material.

[0143] The material selection of the above-mentioned thermal insulation substrate and ceramic particles in this application is the same as the selection range of the above-mentioned ceramic material layer. In some examples, the above-mentioned thermal insulation substrate is a ceramic fiber mat. The ceramic fiber mat has ceramic fibers as the core skeleton, which can not only well infiltrate the liquid phase change material so that the phase change material is filled in the pores of its core skeleton, but also has low thermal conductivity, good high temperature resistance (1280°C), resistance to instantaneous thermal shock, flame retardant properties and mechanical properties, no powdering, and is flexible and resilient, and is compatible with the battery pack manufacturing process.

[0144] In some examples, the thermal insulation substrate includes nano ceramic fibers, which include at least one of silica fibers, alumina fibers, zirconium oxide fibers, silicon aluminum ceramic fibers, boron silicon ceramic fibers, boron aluminum ceramic fibers, and zirconium aluminum silicon ceramic fibers.

[0145] Furthermore, the average diameter of the nano-ceramic fibers is 200-800 nm.

[0146] In some examples of the present application, the ceramic particles include but are not limited to at least one of boron nitride particles, silicon nitride particles, silicon carbide particles, silicon dioxide particles, etc. Further, the Dv50 of the ceramic particles is 60-90 nm. As an example, the Dv50 of the ceramic particles can be any value of 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 83 nm, 85 nm, 90 nm or between any two values. The silicon dioxide particles of the above-mentioned specific particle size are conducive to doping and uniform dispersion in the substrate.

[0147] Phase change microcapsules can be obtained by in-situ polymerization, where the wall material covers the core material. In some examples, the preparation method of phase change microcapsules includes the following steps: dispersing ceramic particles in water to form an aqueous phase; heating the phase change material to a molten state to form an oil phase; mixing the aqueous phase and the oil phase, stirring to form a Pickering emulsion, adding the raw materials required for preparing the polymer matrix of the wall material (such as water-soluble polymerization monomers or prepolymer aqueous solutions) to the Pickering emulsion, stirring and polymerizing at room temperature, and generating a non-water-soluble polycondensate (i.e., polymer matrix) with a cross-linked three-dimensional network structure at the interface of the emulsion.

[0148] The polymer matrix of the above material has better compatibility with phase change materials such as paraffin, and also facilitates the uniform dispersion of ceramic particles, thereby ensuring the stability of phase change microcapsules.

[0149] See also Fig. 9 and Fig.10 Another embodiment of the present application further provides a battery 30, which includes any of the above-mentioned composite thermal insulation pads 10.

[0150] Further, the battery 30 further includes one or more battery cells 20, and a composite thermal insulation pad 10 is provided between at least two adjacent battery cells 20. Optionally, a composite thermal insulation pad 10 is provided between any two adjacent battery cells 20. Further, a composite thermal insulation pad 10 is provided between the large surfaces of at least two adjacent battery cells 20.

[0151] It is understandable that the above-mentioned composite thermal insulation pad 10 may also be provided between the battery cell 20 and the inner wall of the battery 30 shell.

[0152] It is understood that the shape of the battery cell 20 includes but is not limited to a square or a cylinder. The composite thermal insulation pad 10 can be arranged in a manner that is consistent with the shape of the battery cell 20 .

[0153] In some of the embodiments, the battery cell 20 is square, and the composite thermal insulation pad 10 is disposed on a side surface of the battery cell 20 with a larger area to increase its contact area and improve the thermal insulation performance.

[0154] Furthermore, the composite thermal insulation pad 10 is disposed between the large surfaces of two adjacent battery cells 20 .

[0155] In this application, unless otherwise specified, "battery cell 20" refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and further, generally speaking, at least includes a positive electrode sheet, a negative electrode sheet and an electrolyte. During the battery charging and discharging process, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays the role of conducting active ions between the positive electrode sheet and the negative electrode sheet.

[0156] It is understandable that after the multiple battery cells 20 are connected to each other and arranged in a certain order, they can be directly placed in the box to assemble into a battery 30. Alternatively, multiple battery cells 20 can be first formed into a battery module, and then multiple battery modules are connected to each other to form a whole, and finally the whole battery module is placed in the box to form a battery 30.

[0157] Generally, the battery cell 20 includes a housing, a cover plate, and an electrode assembly. The electrode assembly is accommodated in the housing, and the cover plate is sealed at the opening. For example, Fig.11The battery cell 20 is a square structure as an example. The battery cell 20 includes a housing 21, a cover plate 23 and an electrode assembly 22. The electrode assembly 22 is accommodated in the housing 21, and the cover plate 23 is sealed at the opening. The electrode assembly 22 includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet, the negative electrode sheet and the separator can be formed by a winding process or a lamination process.

[0158] Furthermore, the electrode assembly 22 also includes an electrolyte, such as an electrolyte. The electrolyte is infiltrated in the electrode assembly 22. The number of electrode assemblies 22 included in the battery cell 20 can be one or more, and those skilled in the art can select according to specific actual needs.

[0159] Furthermore, one or both ends of the housing 21 are provided with an opening.

[0160] Further, the housing 21 is a rectangular housing, and the opening direction of the housing 21 is the height direction of the housing 21. Further, both ends of the housing 21 are provided with openings, and the two openings are arranged oppositely along the height direction of the housing 21. Further as a non-limiting example, the height of the housing 21 is 80 mm to 210 mm; further as a non-limiting example, the length of the housing 21 is 90 mm to 240 mm; further as a non-limiting example, the width of the housing 21 is 20 mm to 80 mm.

[0161] Furthermore, the battery cell 20 and the shell 21 are rectangular shells, and the composite insulation pad 10 is arranged on the larger side of the battery cell 20, which is perpendicular to the above-mentioned width direction, that is, the side formed by the two sides of the above-mentioned length direction and height direction.

[0162] As a further non-limiting example, the wall thickness of the housing 21 is 0.5 mm to 0.8 mm.

[0163] Furthermore, the housing 21 is an aluminum alloy housing; for example, a three-series aluminum alloy housing or a five-series aluminum alloy housing.

[0164] Furthermore, the aluminum alloy of the three-series aluminum alloy shell includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%.

[0165] Furthermore, the aluminum alloy of the fifth series aluminum alloy shell includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0166] Please continue reading Fig.11 In some embodiments, the battery cell 20 further includes an explosion-proof valve 24, a pressure relief hole is provided on the shell 21, and the explosion-proof valve 24 covers the pressure relief hole. The explosion-proof valve 24 is arranged on one side of the shell 21, specifically on the cover plate 23. The composite thermal insulation pad 10 is arranged close to the explosion-proof valve 24 at the end where the thickness of the thermal conductive layer 12 is thinner. The explosion-proof valve 24 is a safety valve, and its main function is to monitor the pressure and temperature inside the battery. When the pressure or temperature exceeds the set value, the explosion-proof valve 24 will rupture and release pressure to reduce the pressure inside the battery and avoid the occurrence of explosion accidents. When heat accumulates, the temperature close to the side of the explosion-proof valve 24 is higher. Therefore, through the setting of the above-mentioned composite thermal insulation pad 10, the heat is diffused more and faster from the explosion-proof valve to the other side, which is conducive to rapid heat dissipation and prevention or slowing down of thermal runaway.

[0167] In such Fig.11 In the specific example, the explosion-proof valve 24 is located at the top of the housing 21. Therefore, when thermal runaway occurs, the temperature of the upper and lower parts of the battery cell 20 is uneven, the temperature of the top and middle parts near the explosion-proof valve 24 is higher, and the temperature of the bottom part is lower. Therefore, by setting the composite thermal insulation pad 10 containing the thermal conductive layer 12, the heat is diffused more and faster from the top where the explosion-proof valve 24 is located to the bottom, which is conducive to rapid heat dissipation and prevents or slows down the thermal runaway phenomenon.

[0168] See also Fig.12 In some embodiments, the battery 30 further includes a heat dissipation component 32, and the composite thermal insulation pad 10 is disposed close to the heat dissipation component 32 at the end where the thermal conductive layer 12 is thicker. In this way, the heat can be diffused more and faster to the heat dissipation component 32 through the thermal conductive layer 12 of the composite thermal insulation pad 10, which is conducive to rapid heat dissipation and prevents or slows down thermal runaway. Furthermore, the heat dissipation component 32 is located on one side of one or more battery cells 20. Fig.12 In the specific example, the heat dissipation component 32 is located at the bottom of the battery cell 20, and the battery cell 20 is arranged above the heat dissipation component 32, so that the lower end of the battery cell 20 is in contact with or close to the heat dissipation component 32, and the heat dissipation is faster. By setting the composite thermal insulation pad 10 containing the thermal conductive layer 12, more heat is transferred from the explosion-proof valve 24 to the heat dissipation component 32 more quickly, which can improve the thermal diffusion performance of the battery.

[0169] Furthermore, the heat dissipation component 32 includes at least one of a water cooling component and an air cooling component, etc. The water cooling component includes but is not limited to a water cooling plate.

[0170] In some of the embodiments, the battery 30 further includes a third adhesive layer, one side of which is disposed on the outer surface of the outer insulation layer (the first insulation layer 111 and / or the second insulation layer 112) of the composite insulation pad 10, and the other side is used to bond the composite insulation pad 10 to a designated position of the battery 30, for example, the other side is bonded to a surface (for example, a larger surface) of the battery cell 20.

[0171] Another embodiment of the present application further provides an electrical device, including the above-mentioned battery provided in the present application. The above-mentioned battery can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device. The electrical device may include mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto. Among them, the mobile device may be, for example, a mobile phone, a laptop computer, etc.; the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but are not limited thereto.

[0172] As an electrical device, a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.

[0173] Fig.13 The power consumption device 40 is taken as an example. The power consumption device 40 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the power consumption device's requirements for high power and high energy density of secondary batteries, a battery pack or a battery module may be used.

[0174] Another example of a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.

[0175] Example 1

[0176] The composite thermal insulation pad 10 of embodiment 1, such as Figure 8 As shown, it includes a first heat insulation layer 111, a first adhesive layer 151, a phase change material layer 113, a second adhesive layer 152 and a second heat insulation layer 112 which are stacked in sequence. A first encapsulation layer 131 is disposed on the outer surface of the phase change material layer 113 to encapsulate the phase change material layer 113. The heat conduction layer 12 is disposed in the phase change material layer 113.

[0177] The first insulation layer 111 and the second insulation layer 112 are both made of silica aerogel ceramic felt, and both are 1.2 mm thick. The outer surfaces of the first insulation layer 111 and the second insulation layer 112 are also provided with a second packaging layer, which is a PET packaging film, and the thickness of the single-sided PET packaging film is 0.1 mm.

[0178] The thickness of the first adhesive layer 151 and the second adhesive layer 152 are both 0.1 mm; they are both made of silicone adhesive layer.

[0179] The phase change material layer 113 includes a heat insulating substrate and a phase change material filled in the pores of the heat insulating substrate. The specific composition of the phase change material is paraffin, specifically C 28 H 58 , C 38 H 78 and C 57 H 116 The heat insulating substrate is a silicon dioxide ceramic fiber felt. The thickness of the heat insulating substrate is 0.5 mm. The first packaging layer 131 is an aluminum plastic film with a single-side thickness of 0.1 mm. The heat conducting layer 12 is a copper metal layer, which is a special-shaped metal copper sheet (with a triangular cross section) with a height of 170 mm, a width of 0 at the upper end and a width of 0.05 mm at the lower end.

[0180] Comparative Example 1

[0181] The composite thermal insulation pad of Comparative Example 1 is substantially the same as that of Example 1, except that no thermal conductive layer 12 is provided in the thermal insulation substrate.

[0182] The following is a performance test.

[0183] The composite thermal insulation pads prepared in Example 1 and Comparative Example 1 were tested for thermal insulation performance.

[0184] The test method is as follows: one side of the composite thermal insulation pad is burned with butane flame, and the other side is not treated for 1200s. Temperature sensing wires are installed on two opposite back sides of the composite thermal insulation pad (the specification is a rectangle of 100mm×100mm), and the real-time temperature of the two sides of the composite thermal insulation pad is measured within 1200s to obtain the temperature change curve of the two sides of the composite thermal insulation pad, which can be used to judge the thermal insulation effect of the composite thermal insulation pad.

[0185] The side of the composite thermal insulation pad that directly contacts the butane flame is the hot side, and the other side opposite to the hot side is the cold side. There are three temperature sampling points for the hot side and the cold side, one is the center point, and the other two are distributed symmetrically with the center point, with a spacing of 15 mm from the center point. The average value of the three sampling points is taken as the real-time temperature value of the hot side and the cold side.

[0186] The test results of Example 1 and Comparative Example 1 are as follows Fig.14 The temperature change curves of the hot side and the cold side of Example 1 are a1 and a2 respectively. The temperature change curves of the hot side and the cold side of Comparative Example 1 are b1 and b2 respectively.

[0187] from Fig.14It can be seen that within the test time of 1200s, when the temperature of the hot surface reaches nearly 1000℃~1100℃, due to the thermal insulation effect of the composite thermal insulation pad, the highest temperature of the cold surface in Example 1 is about 100℃, and the temperature of the cold surface in Comparative Example 1 is about 300℃. Especially within the first 60s, although the temperature of the hot surface rises, the cold surface in Example 1 has a lower temperature platform (about 50℃). As the test time increases and the heat diffuses further, the temperature of the cold surface rises and basically maintains a temperature platform near 100℃. The maintenance time at the lower temperature platform is the phase change platform time shown in Table 1. It can be seen that compared with Comparative Example 1, Example 1 can maintain a lower temperature platform for a longer time.

[0188] Note: The mass in Table 1 refers to the total mass of the composite thermal insulation pad.

[0189] Table 1

[0190]

[0191] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0192] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A composite thermal insulation pad, characterized in that: include: Thermal insulation pad body; and The heat-conducting layer is arranged inside the heat-insulating pad body, and the thickness of the heat-conducting layer increases in a first direction from one end to the other end of the heat-insulating pad body.

2. The composite thermal insulation pad according to claim 1, characterized in that: The heat conducting layer includes at least one of a metal layer and a graphene film layer.

3. The composite thermal insulation pad according to claim 1, characterized in that: The thickness of the heat conducting layer gradually increases in the first direction.

4. The composite thermal insulation pad according to claim 3, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The size of the heat-conducting layer in the first direction is 80 mm to 400 mm; (2) The heat conductive layer includes a first end with a smaller thickness and a second end with a larger thickness in the first direction. The thickness of the first end is 0 to 0.02 mm, and the thickness of the second end is 0.03 mm to 0.05 mm.

5. The composite thermal insulation pad according to any one of claims 1 to 4, characterized in that: The cross-sectional shape of the heat-conducting layer in the thickness direction of the composite thermal insulation pad includes one of a triangle and a trapezoid.

6. The composite thermal insulation pad according to any one of claims 1 to 4, characterized in that: The thermal insulation pad body comprises a first thermal insulation layer, a phase change material layer and a second thermal insulation layer which are stacked in sequence, and the thermal conductive layer is arranged inside the phase change material layer.

7. The composite thermal insulation pad according to claim 6, characterized in that: The phase change material layer comprises a heat insulation substrate and a phase change material. The phase change material is filled in the pores of the heat insulation substrate. The heat conductive layer is arranged in the heat insulation substrate.

8. The composite thermal insulation pad according to claim 6, characterized in that: The cross-sectional shape of the phase change material layer and the composite thermal insulation pad in the thickness direction of the composite thermal insulation pad is rectangular.

9. The composite thermal insulation pad according to claim 6, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The thickness of the first thermal insulation layer is 0.5 mm to 8 mm; (2) The thickness of the phase change material layer is 0.1 mm to 6 mm; (3) The thickness of the second heat insulation layer is 0.5 mm to 8 mm.

10. The composite thermal insulation pad according to claim 6, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The composite thermal insulation pad further includes a first encapsulation layer, which is disposed on the outer peripheral side of the phase change material layer and encapsulates the phase change material layer; (2) The composite thermal insulation pad further includes a second packaging layer, which is disposed on the outer peripheral side of the first thermal insulation layer and packages the first thermal insulation layer; (3) The composite thermal insulation pad further includes a third encapsulation layer, which is disposed on the outer peripheral side of the second thermal insulation layer and encapsulates the second thermal insulation layer.

11. The composite thermal insulation pad according to claim 10, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The first encapsulation layer, the second encapsulation layer and the third encapsulation layer are each independently an aluminum-plastic film or a polymer encapsulation film; (2) The thickness of the first encapsulation layer, the second encapsulation layer, and the third encapsulation layer are each independently 0.1 mm to 0.3 mm.

12. The composite thermal insulation pad according to claim 6, characterized in that: The edges of the first heat-insulating layer and the second heat-insulating layer cooperate with each other to form an assembly cavity, and the phase-change material layer is located in the assembly cavity.

13. The composite thermal insulation pad according to claim 12, characterized in that: An edge of at least one side surface of at least one of the first heat-insulating layer and the second heat-insulating layer forms a convex portion, and the convex portion encloses and forms at least a portion of the assembly cavity.

14. The composite thermal insulation pad according to any one of claims 1 to 4 and 7 to 13, characterized in that: The composite thermal insulation pad also includes a first packaging frame and a second packaging frame, and the first packaging frame cooperates with the second packaging frame to fix the thermal insulation pad body provided with the heat conductive layer.

15. The composite thermal insulation pad according to claim 14, characterized in that: The first packaging frame has a first limiting groove, the second packaging frame has a second limiting groove, and the thermal insulation pad body provided with the thermal conductive layer is limited in a limiting space formed by the first limiting groove and the second limiting groove.

16. A battery, characterized in that: It comprises a battery cell and a composite thermal insulation pad as claimed in any one of claims 1 to 15, wherein the composite thermal insulation pad is arranged adjacent to the battery cell.

17. The battery according to claim 16, characterized in that The battery cell comprises a shell and an explosion-proof valve, wherein the explosion-proof valve is arranged on one side of the shell, and the composite thermal insulation pad is arranged close to the explosion-proof valve at the end where the thermal conductive layer is thinner.

18. The battery according to claim 16 or 17, characterized in that: The battery further comprises a heat dissipation component, and the composite heat insulation pad is arranged close to the heat dissipation component with the end of the heat conductive layer having a thicker thickness.

19. The battery according to claim 16 or 17, characterized in that: The battery comprises a plurality of battery cells, and the composite thermal insulation pad is arranged between at least two adjacent battery cells.

20. The battery according to claim 19, characterized in that The composite heat-insulating pad is arranged between at least two adjacent large surfaces of the battery cells.

21. An electrical device, characterized in that: Comprising a battery as claimed in any one of claims 16 to 20.

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