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. The composite heat insulation pad comprises a phase change material layer, an outer side heat insulation layer and a packaging layer, wherein the packaging layer is arranged on the peripheral side of at least one of the phase change material layer and the outer side heat insulation layer. The composite heat insulation pad has good heat insulation performance, is applied to the battery and has the effect of retarding 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 being used more and more widely in the market, and people are demanding higher and higher performance from batteries, such as higher energy density. However, battery cells with higher energy density have large residual energy after thermal runaway. When one of the battery cells goes into thermal runaway, its heat will continue to transfer from one battery cell to the adjacent battery cell, thus causing heat diffusion of the entire battery, causing damage to the entire battery. Therefore, how to 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 the problem of battery thermal runaway.

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

[0005] a phase change material layer;

[0006] an outer heat-insulating layer, disposed on at least one side of the outer periphery of the phase change material layer; and

[0007] The encapsulation layer is provided on the outer peripheral side of at least one of the phase change material layer and the outer heat insulating layer.

[0008] The above-mentioned composite thermal insulation pad of the present application includes an outer thermal insulation layer which mainly plays a role of thermal insulation and a phase change material layer which mainly plays a role of heat absorption, and a packaging layer is provided on the outer peripheral side of at least one of the phase change material layer and the outer thermal insulation layer, so that the packaging layer can physically isolate the phase change material layer and the outer thermal insulation layer, which can inhibit the phase change material layer from diffusing into the inner part of the outer thermal insulation layer and forming a heat conduction path to a certain extent, so that the above-mentioned composite thermal insulation pad has better thermal insulation performance, and is applied to batteries to have the effect of slowing down thermal runaway of the batteries.

[0009] In some embodiments, the encapsulation layer includes a first encapsulation layer, the first encapsulation layer is arranged on the outer peripheral side of the phase change material layer, the phase change material layer includes a heat insulation substrate and a phase change material filled in the heat insulation substrate, and the first encapsulation layer and the phase change material layer form a composite phase change layer;

[0010] The outer heat insulation layer is disposed on at least one side of the outer circumference of the composite phase change layer.

[0011] In some embodiments, the composite thermal insulation pad satisfies at least one of the following conditions:

[0012] (1) The first packaging layer is an aluminum-plastic film or a polymer packaging film;

[0013] (2) The thickness of the first packaging layer is 0.1 mm to 0.3 mm;

[0014] (3) The composite thermal insulation pad further includes an adhesive layer, and the outer thermal insulation layer and the first packaging layer are connected via the adhesive layer;

[0015] (4) The thickness of the composite phase change layer is 1 mm to 6 mm;

[0016] (5) The thickness of the phase change material layer accounts for 70% to 96% of the total thickness of the composite phase change layer;

[0017] (6) The thickness ratio of the composite phase change layer to the outer thermal insulation layer is 0.15-12:1;

[0018] (7) The length and width of the outer heat insulation layer are respectively adapted to the length and width of the composite phase change layer; or, at least one of the length and width of the outer heat insulation layer is larger than the corresponding length or width of the composite phase change layer.

[0019] In some embodiments, the encapsulation layer includes a second encapsulation layer, the second encapsulation layer is arranged on the outer peripheral side of the outer heat insulation layer, and the second encapsulation layer and the outer heat insulation layer form an encapsulation heat insulation layer;

[0020] The packaging heat-insulating layer is disposed on at least one side of the outer circumference of the phase-change material layer.

[0021] In some embodiments, the second packaging layer has a second packaging margin portion, and the second packaging margin portion is folded and located between the packaging heat insulation layer and the phase change material layer.

[0022] In some embodiments, the composite thermal insulation pad satisfies at least one of the following conditions:

[0023] (1) The second packaging layer is an aluminum-plastic film or a polymer packaging film;

[0024] (2) The thickness of the second packaging layer is 0.05 mm to 0.1 mm.

[0025] In some embodiments, the encapsulation layer includes a third encapsulation layer, and the third encapsulation layer is disposed on a common outer peripheral side of the phase change material layer and the outer heat insulation layer.

[0026] In some embodiments, the composite thermal insulation pad satisfies at least one of the following conditions:

[0027] (1) The third encapsulation layer is a polymer encapsulation film;

[0028] (2) The thickness of the third packaging layer is 0.05 mm to 0.1 mm.

[0029] In some embodiments, the outer heat insulation layer is provided with a hollow cavity, and a solid phase change material is provided in the hollow cavity.

[0030] In some embodiments, the outer heat insulation layer is disposed on at least one of two sides of the phase change material layer in a thickness direction.

[0031] In some embodiments, the outer thermal insulation layer includes a first thermal insulation layer and a second thermal insulation layer;

[0032] The first heat insulation layer and the second heat insulation layer are respectively arranged on both sides of the phase change material layer in a thickness direction, so that the phase change material layer is sandwiched between the first heat insulation layer and the second heat insulation layer.

[0033] In some embodiments, the edges of the first thermal insulation layer and the second thermal insulation layer cooperate with each other to form an assembly cavity, and the composite phase change layer is located in the assembly cavity.

[0034] In some embodiments, 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 at least a portion of the assembly cavity.

[0035] In some embodiments, the composite thermal insulation pad further includes a first packaging frame and a second packaging frame, and the first packaging frame and the second packaging frame can cooperate with each other and fix the phase change material layer, the outer thermal insulation layer and the packaging layer.

[0036] In some embodiments, the first packaging frame has a first limiting groove, the second packaging frame has a second limiting groove, and the phase change material layer, the outer heat insulation layer and the packaging layer are limited in a limiting space formed by the first limiting groove and the second limiting groove.

[0037] In some embodiments, the composite thermal insulation pad satisfies at least one of the following conditions:

[0038] (1) The outer insulation layer is a ceramic material layer;

[0039] (2) The thickness of the outer insulation layer is 0.5 mm to 8 mm;

[0040] (3) The composite thermal insulation pad also includes a release adhesive layer, which includes an adhesive layer and a release film. The adhesive layer is arranged on the outer surface of the outer thermal insulation layer, and the release film is arranged on the outer surface of the adhesive layer.

[0041] In a second aspect, the present application provides a battery comprising the above-mentioned composite thermal insulation pad.

[0042] In some of the embodiments, a plurality of battery cells are further included, and the composite thermal insulation pad is disposed between at least two adjacent battery cells.

[0043] In some of the embodiments, the composite thermal insulation pad is disposed between the large surfaces of two adjacent battery cells.

[0044] In a third aspect, the present application provides an electrical device, comprising the battery as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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;

[0046] 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;

[0047] 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;

[0048] 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;

[0049] 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;

[0050] 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;

[0051] 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;

[0052] Figure 8 for Figure 7 A schematic cross-sectional view of the composite thermal insulation pad shown in FIG.

[0053] Fig. 9 for Figure 8 A schematic cross-sectional view of the composite thermal insulation pad shown in FIG.

[0054] Fig.10 This is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0055] Fig.11 A schematic diagram of the structure of a battery according to one embodiment of the present application;

[0056] Fig.12This is a schematic diagram of the exploded structure of a battery according to one embodiment of the present application;

[0057] FIG13 is a schematic diagram of the structure of a battery cell in a battery according to an embodiment;

[0058] FIG. 14 is a schematic diagram of an electrical device using a battery as a power source according to an embodiment of the present application.

[0059] Description of reference numerals:

[0060] 10. Composite thermal insulation pad; 110. Phase change material layer; 121. First thermal insulation layer; 1212. Solid phase change material; 122. Second thermal insulation layer; 123. Third thermal insulation layer; 131. First packaging layer; 1311. First packaging margin; 132. Second packaging layer; 1321. Second packaging layer margin; 133. Third packaging layer; 1331. Third packaging layer margin; 141. First packaging frame; 142. Second packaging frame; 151. First adhesive layer; 152. Second adhesive layer;

[0061] 20. Battery cell; 21. Housing; 22. Electrode assembly; 23. Cover plate;

[0062] 30. Battery;

[0063] 40. Electrical equipment. DETAILED DESCRIPTION

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] "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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] In order to solve the above-mentioned battery thermal runaway problem and reduce the damage and risk to the entire battery.

[0074] See also Figure 1 An embodiment of the present application provides a composite thermal insulation pad 10, including a phase change material layer 110, an outer thermal insulation layer and a packaging layer.

[0075] The outer heat insulating layer is disposed on at least one side of the outer periphery of the phase change material layer 110. The encapsulation layer is disposed on the outer periphery of at least one of the phase change material layer 110 and the outer heat insulating layer.

[0076] It can be understood that the peripheral side of the phase change material layer 110 is the entire peripheral surface of the phase change material layer 110 as an independent entity.

[0077] It can be understood that the outer peripheral side of the outer thermal insulation layer is the outer peripheral surface of the outer thermal insulation layer as an independent entity.

[0078] The outer peripheral sides of the phase change material layer 110 and the outer heat insulating layer are all the outer peripheral surfaces of the whole formed by the phase change material layer 110 and the outer heat insulating layer.

[0079] It is understandable that the encapsulation layer can be disposed on the outer peripheral side of the phase change material layer 110 and the outer insulation layer alone, or on the outer peripheral side formed by the two together, or a combination of these. In other words, the encapsulation layer is disposed on the outer peripheral side of any one of the phase change material layer 110 and the outer insulation layer and / or both.

[0080] The above-mentioned composite thermal insulation pad of the present application includes an outer thermal insulation layer which mainly plays a role of thermal insulation and a phase change material layer 110 which mainly plays a role of heat absorption, and a packaging layer is provided on the outer peripheral side of at least one of the phase change material layer 110 and the outer thermal insulation layer, so that the packaging layer can physically isolate the phase change material layer 110 and the outer thermal insulation layer or isolate the composite thermal insulation pad from the outside, so that the phase change material layer 110 can be inhibited from diffusing into the inner part of the outer thermal insulation layer or the outer thermal insulation pad can be inhibited from being contaminated by the outside to a certain extent, thereby forming a heat conduction path problem, so that the above-mentioned composite thermal insulation pad 10 has better thermal insulation performance, and it is applied to batteries to have the effect of slowing down thermal runaway of the batteries.

[0081] In some embodiments, the encapsulation layer includes a first encapsulation layer 131. The first encapsulation layer 131 is disposed on the outer peripheral side of the phase change material layer 110 to form a composite phase change layer with the phase change material layer 110. In other words, the composite phase change layer includes the phase change material layer 110 and the first encapsulation layer 131, and the first encapsulation layer 131 is disposed on the outer peripheral side of the phase change material layer 110. Correspondingly, the outer heat insulation layer is disposed on at least one side of the outer peripheral side of the composite phase change layer.

[0082] In this way, the above-mentioned composite thermal insulation pad 10, on the one hand, the outer thermal insulation layer is arranged on at least one side of the outer peripheral side of the first encapsulation layer 131, and the phase change material layer 110 in the first encapsulation layer 131 can absorb the heat transferred from the outer thermal insulation layer to play a thermal insulation role. On the other hand, the first encapsulation layer 131 is arranged on the outer peripheral side of the phase change material layer 110 to form a composite phase change layer 1, so that the phase change material layer 110 in the composite phase change layer 1 is physically isolated from the outer thermal insulation layer, and then before the first encapsulation layer 131 fails, the phase change material will not diffuse into the inner part of the outer thermal insulation layer to form a heat conduction path, and then will not change the structure of the outer thermal insulation layer and its thermal insulation performance.

[0083] In the composite thermal insulation pad 10, on the one hand, the outer thermal insulation layer is arranged on at least one side of the outer peripheral side of the first encapsulation layer 131, and the phase change material layer 110 in the first encapsulation layer 131 can absorb the heat transferred from the outer thermal insulation layer to play a thermal insulation role. On the other hand, the first encapsulation layer 131 is arranged on the outer peripheral side of the phase change material layer 110 to form a composite phase change layer, so that the phase change material layer 110 in the composite phase change layer is physically isolated from the outer thermal insulation layer, and then before the first encapsulation layer 131 fails, the phase change material will not diffuse into the inner part of the outer thermal insulation layer to form a heat conduction path, and then the structure of the outer thermal insulation layer and its thermal insulation performance will not be changed.

[0084] Traditional technology is limited by structure, and phase change materials can only use solid phase change materials, but the heat absorption capacity of solid phase change materials is limited. The above-mentioned composite thermal insulation pad 10, because its phase change material layer 110 is arranged in the packaging cavity of the first packaging layer 131, so that the phase change material layer 110 is physically isolated from the outer thermal insulation layer, so the phase change material of its phase change material layer 110 can be a solid phase change material, a liquid phase change material, or a solid-liquid mixed phase change material or a semi-solid phase change material. Optionally, the phase change material includes but is not limited to crystal water and salt, phase change molten salt, paraffin, silicone oil, silica-alumina sol, fatty acids, 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.

[0085] In addition, because the phase change material of the phase change material layer 110 undergoes phase change, for example, the solid phase change material at room temperature turns into liquid after absorbing heat, the first encapsulation layer 131 can also serve to isolate the liquid phase change material after phase change from the outer heat insulation layer.

[0086] In addition, some preparation processes inevitably cause the phase change material to contain moisture. The structure in which the phase change material layer 110 is disposed in the packaging cavity of the first packaging layer 131 can prevent moisture overflow from causing adverse effects on the battery.

[0087] In some examples, the packaging layer may be formed by packaging two packaging films, for example, by packaging by edge pressing or edge wrapping, so that a packaging margin portion is provided at the edge of each packaging layer.

[0088] In some embodiments, the first packaging layer 131 has a first packaging margin portion 1311. Further, the first packaging margin portion 1311 is formed into a pressed edge structure by pressing the edge.

[0089] See also Figure 2 Furthermore, the first packaging margin 1311 can also be folded and located between the composite phase change layer and the outer heat insulation layer, so that each side of the packaging film forms a wrapping structure, which can maximize the use of the area of ​​the first packaging layer compared to the above-mentioned edge pressing structure. In other words, if the packaging film of the same size adopts the wrapping structure, a larger area of ​​the composite phase change layer can be filled in the packaging film, thereby increasing the area of ​​the composite phase change layer, increasing the contact area between the composite heat insulation pad 10 and the large surface of the battery, and thus improving the heat insulation performance.

[0090] In some embodiments, the first packaging layer 131 is an aluminum-plastic film or a polymer packaging film.

[0091] Furthermore, the first encapsulation layer 131 is an aluminum-plastic film. Specifically, the first encapsulation layer 131 includes a polypropylene layer, an aluminum layer, and a nylon layer stacked from inside to outside.

[0092] Furthermore, the polymer encapsulation film may be a PET film (polyethylene terephthalate film) or a PI film (polyimide film). In some embodiments, the thickness of the first encapsulation layer 131 is 0.1 mm to 0.3 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, and may be 0.1 mm to 0.15 mm, or 0.2 mm to 0.3 mm.

[0093] See also Figure 3 In some of the embodiments, the composite thermal insulation pad 10 further includes an adhesive layer, and the outer thermal insulation layer is connected to the first packaging layer 131 through the adhesive layer.

[0094] In some of the embodiments, the thickness of the phase change material layer 110 accounts for 70% to 96% of the total thickness of the composite phase change layer; as an example, the thickness may account for 70%, 75%, 80%, 86%, 90%, 92%, 95%, 96%, and further, may be 86% to 96%.

[0095] In some of the embodiments, the thickness of the composite phase change layer is 1 mm to 6 mm, and can be 1 mm to 4 mm. As an example, it can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, or 6 mm. It can also be 1.5 mm to 3.5 mm.

[0096] In some embodiments, the thickness ratio of the composite phase change layer to the outer heat insulation layer is 0.15-12:1, further 0.5-8:1. For example, it can be 0.15:1, 0.5:1, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1.

[0097] Furthermore, the thickness of the outer heat insulation layer 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 optionally 1 mm to 8 mm.

[0098] 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.

[0099] In some embodiments, the length and width of the outer heat insulation layer are respectively adapted to the length and width of the composite phase change layer. In other embodiments, at least one of the length and width of the outer heat insulation layer is greater than the corresponding length or width of the composite phase change layer.

[0100] Please continue reading Figure 1~Figure 3 In some embodiments, the composite thermal insulation pad 10 may further include a second encapsulation layer 132, which is disposed on the outer peripheral side of the outer thermal insulation layer to form an encapsulation thermal insulation layer with the outer thermal insulation layer. In other words, the encapsulation thermal insulation layer includes the outer thermal insulation layer and the second encapsulation layer 132, which is disposed on the outer peripheral side of the outer thermal insulation layer. Accordingly, the encapsulation thermal insulation layer is disposed on at least one side of the outer peripheral side of the phase change material layer 110. In this way, the outer thermal insulation layer is disposed on at least one side of the outer peripheral side of the phase change material layer 110 in a separately encapsulated state.

[0101] In this way, a second packaging layer 132 is arranged on the outer peripheral side of the outer thermal insulation layer, which can play a certain packaging and protection role for the outer thermal insulation layer, and can further reduce the problem of impurities entering the outer thermal insulation layer to form a heat conduction path and affect the thermal insulation performance. In this way, the thermal insulation performance of the above-mentioned composite thermal insulation pad 10 is further improved. When applied to batteries, it has a good effect of preventing thermal runaway of the battery.

[0102] Similarly, the second packaging margin portion 1321 of the second packaging layer 132 can be formed into a pressed edge structure by pressing the edge.

[0103] Please continue reading Figure 2Furthermore, the second packaging margin portion 1321 can also be folded and located between the packaging insulation layer and the phase change material layer 110, so that each side of the packaging film forms a wrapping structure.

[0104] Furthermore, the second packaging layer 132 is an aluminum-plastic film or a polymer packaging film, including but not limited to a PET film (polyethylene terephthalate film) or a PI film (polyimide film).

[0105] In a specific example, the first packaging layer 131 is an aluminum-plastic film, and the second packaging layer 132 is a polymer packaging film.

[0106] Further, the thickness of the second packaging layer 132 is 0.05 mm to 0.1 mm; optionally 0.07 mm to 0.09 mm, and further 0.08 mm±0.005 mm.

[0107] In some embodiments, the encapsulation layer includes a third encapsulation layer 133. The third encapsulation layer 133 is disposed on the common outer peripheral side of the phase change material layer 110 and the outer thermal insulation layer. In other words, the third encapsulation layer 133 is disposed on the outer peripheral side of the phase change material layer 110 and the outer thermal insulation layer as a whole to form an encapsulated thermal insulation layer. In this way, the entire composite thermal insulation pad is encapsulated and protected as a whole by the third encapsulation layer 132.

[0108] Furthermore, the third packaging layer 132 is an aluminum-plastic film or a polymer packaging film, including but not limited to a PET film (polyethylene terephthalate film) or a PI film (polyimide film).

[0109] In a specific example, the third encapsulation layer 133 is an aluminum-plastic film, and the third encapsulation layer 133 is a polymer encapsulation film.

[0110] Further, the thickness of the third encapsulation layer 133 is 0.05 mm to 0.1 mm; optionally 0.07 mm to 0.09 mm, and further 0.08 mm±0.005 mm.

[0111] It can be understood that, in a specific example, the encapsulation layer may only include the third encapsulation layer 133 , without the first encapsulation layer 131 and the second encapsulation layer 132 mentioned above.

[0112] For further information, see Figure 4 In a specific example, the encapsulation layer may include both the first encapsulation layer 131 and the third encapsulation layer 133. Thus, the phase change material layer in the first encapsulation layer 131 may use at least one of liquid, semi-solid or solid phase change materials.

[0113] Furthermore, in another specific example, the encapsulation layer may contain both the second encapsulation layer 132 and the third encapsulation layer 133 .

[0114] It can be understood that when a third encapsulation layer 133 is provided, it is preferable that the first encapsulation margin 1311 of the first encapsulation layer 131 and the second encapsulation margin 1321 of the second encapsulation layer 132 adopt an edge-wrapped structure, which is folded between the layer structures of the composite thermal insulation pad 10 to facilitate the encapsulation operation of the third encapsulation layer 133.

[0115] Furthermore, in another specific example, the encapsulation layer includes the first encapsulation layer 131 , the second encapsulation layer 132 and the third encapsulation layer 133 mentioned above at the same time.

[0116] It can be understood that the first encapsulation layer 131 , the second encapsulation layer 132 and the third encapsulation layer 133 can adopt any one of them, or a combination of multiple ones according to different scene requirements.

[0117] In some embodiments, the outer heat insulation layer is provided with a hollow cavity, and a solid phase change material is provided in the hollow cavity. Since the solid phase change material is provided in the outer heat insulation layer, it will not affect the heat insulation performance of the outer heat insulation layer under normal conditions, and the phase change material located in the inner hollow cavity of the outer heat insulation layer can play a certain role in absorbing heat.

[0118] In some embodiments, the outer heat insulation layer may be provided on at least one of the two sides in the thickness direction of the phase change material layer. In other words, there may be one or more outer heat insulation layers. Accordingly, the entire outer periphery of one or more outer heat insulation layers is encapsulated with a second encapsulation layer 132 to form independent encapsulation heat insulation layers. Alternatively, the outer periphery of each outer heat insulation layer and the phase change material layer 110 as a whole is encapsulated with a third encapsulation layer 133.

[0119] For example, the outer heat insulating layer may be disposed on one side or two opposite sides of the phase change material layer 110 in the thickness direction.

[0120] Please continue reading Figures 1 to 4 In some embodiments, the outer thermal insulation pad includes a first thermal insulation layer 121 and a second thermal insulation layer 122, and the first thermal insulation layer 121 and the second thermal insulation layer 122 are disposed on both sides of the phase change material layer 110 in the thickness direction, so that the phase change material layer 110 is sandwiched between the first thermal insulation layer 121 and the second thermal insulation layer 122. In other words, the first thermal insulation layer 121, the phase change material layer 110 and the second thermal insulation layer 122 are stacked in sequence.

[0121] For further information, see Figure 3 The adhesive layer includes a first adhesive layer 151 and a second adhesive layer 152. The first thermal insulation layer 121 is connected to the first encapsulation layer 131 through the first adhesive layer 151; the second thermal insulation layer 122 is connected to the first encapsulation layer 131 through the second adhesive layer 152. In this way, the first thermal insulation layer 121, the phase change material layer 110 and the second thermal insulation layer 122 of the composite thermal insulation pad 10 are connected and fixed in the thickness direction through the adhesive layer.

[0122] 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.

[0123] Furthermore, the first adhesive layer 151 and the second adhesive layer 152 may also be pressure-sensitive adhesive layers, which may be formed by bonding using a pressure-sensitive adhesive tape, and have the advantages of good adhesion and being less prone to bubbles.

[0124] The first encapsulation layer 131 is arranged on the outer peripheral side of the phase change material layer 110 and constitutes an encapsulation cavity, and the phase change material layer 110 is arranged in the encapsulation cavity. Furthermore, the encapsulation cavity is a closed cavity. The above-mentioned composite thermal insulation pad 10, on the one hand, simultaneously arranges the first thermal insulation layer 121 and the second thermal insulation layer 122, which can play a good thermal insulation role; on the other hand, the phase change material layer 110 is arranged between the first thermal insulation layer 121 and the second thermal insulation layer 122, and the phase change material layer 110 can absorb the heat transferred from the thermal insulation layers on both sides, which can further improve the thermal insulation performance of the above-mentioned composite thermal insulation pad 10.

[0125] It is understandable that the material and thickness of the first heat insulation layer 121 or the second heat insulation layer 122 are the same or similar.

[0126] In some embodiments, the composite thermal insulation pad 10 further includes a release adhesive layer (not shown). The release adhesive layer includes a third adhesive layer and a release film, the third adhesive layer is disposed on the outer surface of the outer thermal insulation layer (i.e., the first thermal insulation layer 121 and / or the second thermal insulation layer 122), and the release film is 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.

[0127] As an example, the above-mentioned release adhesive layer is provided on the outer surfaces of the first insulation layer 121 and the second insulation layer 122 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.

[0128] like Figure 1As shown, the first heat insulation layer 121 and the second heat insulation layer 122 are physically separated by the phase change material layer. In other words, the edges between the first heat insulation layer 121 and the second heat insulation layer 122 are not connected to each other.

[0129] See also Figure 5 In some embodiments, the edges of the first thermal insulation layer 121 and the second thermal insulation layer 122 are connected to each other to form an assembly cavity, and the phase change material layer 110 is located in the assembly cavity. Through this structural setting, the phase change material layer 110 is arranged inside the first thermal insulation layer 121 and the second thermal insulation layer 122, reducing the risk of the phase change material layer 110 falling off.

[0130] Further, at least one side surface edge of at least one of the first thermal insulation layer 121 and the second thermal insulation layer 122 forms a convex portion, and the convex portion encloses at least part of the assembly cavity. As an example, at least one side surface edge of the first thermal insulation layer 121 and the second thermal insulation layer 122 forms a convex portion, and the convex portions of the two are arranged opposite to each other and enclose to form an assembly cavity. Figure 5 In the specific example, convex portions are formed on the four edges of one side surface of the first thermal insulation layer 121 and the second thermal insulation layer 122, and the convex portions of the first thermal insulation layer 121 and the second thermal insulation layer 122 are arranged opposite to each other and enclose to form an assembly cavity.

[0131] Furthermore, in Figure 5 In the specific example, due to the irregular structure of the first insulation layer 121 and the second insulation layer 122, it is easier to operate by using the first encapsulation layer 131 to encapsulate the phase change material layer 110. Furthermore, the third encapsulation layer 133 can be used to encapsulate the phase change material layer 110 and the first insulation layer 121 and the second insulation layer 122 as a whole.

[0132] Furthermore, in Figure 5 In a specific example, when the phase change material layer 110 is disposed inside the first heat insulation layer 121 and the second heat insulation layer 122 , the first package margin portion 1311 is folded and located in the assembly cavity.

[0133] See also Figure 6 In some embodiments, the composite thermal insulation pad 10 further includes a third thermal insulation layer 123, and a phase change material layer 110 is also provided between the second thermal insulation layer 122 and the third thermal insulation layer 123. Furthermore, the composite thermal insulation pad 10 may further include more thermal insulation layers, and the above-mentioned phase change material layer 110 may also be provided between the adjacent thermal insulation layers.

[0134] Furthermore, the selection range of materials and thicknesses of the third thermal insulation layer 123 and other thermal insulation layers may be the same as that of the first thermal insulation layer 121 and the second thermal insulation layer 122; the specific materials and specific thicknesses may be the same or different.

[0135] Furthermore, in Figure 6In the specific example shown, the encapsulation layer includes the first encapsulation layer 131 and the second encapsulation layer 132 described above.

[0136] See also Figure 7 and Figure 8 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 phase change material layer 110 , the outer thermal insulation layer and the packaging layer.

[0137] Furthermore, the first packaging frame 141 is disposed on one side of the first insulation layer 121 , and the second packaging frame 142 is disposed on one side of the second insulation layer 122 . The first packaging frame 141 and the second packaging frame 142 cooperate to fix the first insulation layer 121 , the phase change material layer 110 , the packaging layer and the second insulation layer 122 .

[0138] Further, the first encapsulation frame 141 and the second encapsulation frame 142 are each independently a rubber frame or a silicone frame. In other words, the materials of the first encapsulation frame 141 and the second encapsulation frame 142 are each independently rubber or silicone. Further, the first encapsulation frame 141 and the second encapsulation frame 142 are both rectangular frame structures, such as a square frame, and specifically can be a silicone square frame.

[0139] In such Figure 8 In a specific example, the encapsulation layer also includes the above-mentioned first encapsulation layer 131 and the second encapsulation layer 132, which respectively encapsulate the phase change material layer 110 and the outer insulation layer. In this case, the connection method of the first encapsulation frame 141 and the second encapsulation frame 142 is adopted, and the structure is relatively stable. Furthermore, liquid or semi-solid phase change material can be used in the phase change material layer 110.

[0140] In such Figure 8 In the example shown, the first encapsulation frame 141 has a first limiting groove (not shown), the second encapsulation frame 142 has a second limiting groove (not shown), and the first thermal insulation layer 121, the phase change material layer 110, the encapsulation layer and the second thermal insulation layer 122 are 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 phase change material layer 110, the outer thermal insulation layer and the encapsulation layer in the thickness direction and the radial direction of the composite thermal insulation pad 10, thereby improving the structural stability of the composite thermal insulation pad 10.

[0141] 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. Further, at this time, the first packaging margin portion 1311 of the first packaging layer 131 can be located between the first packaging frame 141 and the second packaging frame 142, such as Figure 7 As shown, the first packaging margin portion 1311 is pressed in the middle by the first packaging frame 141 and the second packaging frame 142 .

[0142] 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 121 and second thermal insulation layer 122 capable of forming an assembly cavity are provided at the same time, the first packaging margin portion 1311 of the first packaging layer 131 can pass through between the convex portions of the first thermal insulation layer 121 and the second thermal insulation layer 122 and be located between the first packaging frame 141 and the second packaging frame 142, or the first packaging margin portion 1311 of the first packaging layer 131 can also be folded and located in the assembly cavity.

[0143] See also Fig. 9 In some embodiments, the outer heat insulation layer is provided with a hollow cavity, and a solid phase change material 1212 is provided in the hollow cavity. Since the outer heat insulation layer is provided with a solid phase change material, it will not affect the heat insulation performance of the outer heat insulation layer under normal conditions, and the phase change material located in the inner hollow cavity of the outer heat insulation layer can play a certain role in absorbing heat, so the outer side of the outer heat insulation layer may not be provided with a second encapsulation layer 132. Furthermore, the encapsulation layer may also only include the above-mentioned first encapsulation layer 131 to encapsulate and protect the phase change material layer 110 therein.

[0144] Furthermore, in Fig. 9 In the specific example shown, the encapsulation layer includes the first encapsulation layer 131 and the second encapsulation layer 132 described above, which respectively encapsulate the phase change material layer 110 and the outer heat insulation layer. At this time, the connection method of the first encapsulation frame 141 and the second encapsulation frame 142 is adopted, and the structure is relatively stable. Furthermore, the phase change material layer 110 can use liquid or semi-solid phase change material.

[0145] See also Fig.10 In other embodiments, the outer surface of the first thermal insulation layer 121 is flush with the outer surface of the first packaging frame 141, and / or the outer surface of the second thermal insulation layer 122 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.

[0146] 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 phase change material layer, the outer insulation layer and the packaging layer around, 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 insulation layer 121 can be flush with the outer surface of the first packaging frame 141, and the outer surface of the second insulation layer 122 can be flush with the outer surface of the second packaging frame 142.

[0147] It can be understood that in some embodiments, the first thermal insulation layer 121, the phase change material layer, the second thermal insulation layer 122, and the third thermal insulation layer 123 can be connected by the above-mentioned adhesive layer instead of the above-mentioned packaging frame, or by the above-mentioned packaging frame instead of the above-mentioned adhesive layer, or by both the above-mentioned adhesive layer and the packaging frame, or by none of them, for example, the first thermal insulation layer 121 can be directly formed on the surface of the phase change material layer 110 in the form of a coating.

[0148] Furthermore, the first thermal insulation layer 121 , the second thermal insulation layer 122 and the third thermal insulation layer 123 each independently include at least one of thermal insulation felt and thermal insulation coating.

[0149] Furthermore, when any of the above-mentioned thermal insulation layers includes both of the thermal insulation felt and the thermal insulation coating, the thermal insulation coating may be optionally disposed on a side closer to the phase change material layer 110, specifically, the thermal insulation coating is disposed on the surface of the first encapsulation layer 131 of the phase change material layer 110, and the thermal insulation felt is disposed on a side further away from the phase change material layer 110. 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.

[0150] For example, Figure 1 In the example, the first thermal insulation layer 121 and the second thermal insulation layer 122 are thermal insulation felts, and the third thermal insulation layer 123 is also thermal insulation felt. In other examples, the first thermal insulation layer 121 and the second thermal insulation layer 122 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 smaller occupied space and better thermal insulation performance.

[0151] For example, in Figure 5 In the example shown, the first thermal insulation layer 121 and the second thermal insulation layer 122 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.

[0152] It is understood that the thermal insulation felt can be connected to the phase change material layer 110 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 phase change material layer 110. As an example, the thermal insulation coating can be prepared by coating the first packaging layer 131 of the phase change material layer 110 with a slurry and then drying it to form a coating.

[0153] 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 outer thermal insulation layer is a ceramic material layer. In other words, the first thermal insulation layer 121, the second thermal insulation layer 122, and the third thermal insulation layer 123 are each independently a ceramic material layer.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] In some of the embodiments, the first thermal insulation layer 121, the second thermal insulation layer 122 and the third thermal insulation layer 123 each independently meet the following conditions: the thermal conductivity at 25°C is ≤0.020W / m·K, the thermal conductivity at 200°C is ≤0.027W / m·K, the thermal conductivity at 300°C is ≤0.035W / m·K, and the thermal conductivity at 500°C is ≤0.080W / m·K.

[0158] In some embodiments, the density of the first thermal insulation layer 121, the second thermal insulation layer 122, and the third thermal insulation layer 123 is independently 0.2-0.22 g / cm 3 Further, the thickness of the first heat insulation layer 121 is 0.5 mm to 8 mm, and 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.

[0159] Furthermore, the thickness of the second heat insulation layer 122 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.

[0160] In some embodiments, the phase change material layer 110 may include a heat insulation substrate in addition to the phase change material, and the phase change material is filled in the heat insulation substrate. In other words, the pores of the heat insulation substrate are filled with the phase change material.

[0161] The thermal insulation substrate may be a ceramic material substrate, such as ceramic fiber felt.

[0162] 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.

[0163] It can be understood that the phase change material layer 110 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 110 containing the thermal insulation substrate can also play a role in heat insulation. When the phase change material vaporizes and breaks through the first packaging layer 131, that is, the composite thermal insulation pad 10 fails, the thermal insulation substrate in the phase change material layer 110 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. In addition, since the thermal insulation substrate is provided in the phase change material layer 110, it also has good compression performance.

[0164] 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 110 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 the phase change material. It can be understood that in some examples, the pores of the thermal insulation substrate can also be directly filled with the phase change material and the above-mentioned phase change microcapsules at the same time.

[0165] The above-mentioned phase change material layer 110 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.

[0166] In this way, the phase change microcapsules in the phase change material layer 110 absorb heat. When the battery cell thermally runs away, the phase change material in the adjacent composite insulation pad 10 vaporizes and breaks the first packaging layer 131, that is, the composite insulation pad 10 fails. At this time, the insulation substrate in the phase change material layer 110 can continue to play an insulation role.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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).

[0171] 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.

[0172] 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.

[0173] 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.

[0174] In some examples, 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 specific particle size are conducive to doping and uniform dispersion in the substrate.

[0175] 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 polymer monomers or prepolymer aqueous solutions) to the Pickering emulsion, and stirring and polymerizing at room temperature to generate a non-water-soluble polycondensate (i.e., a polymer matrix) with a cross-linked three-dimensional network structure at the interface of the emulsion.

[0176] The polymer substrate of the above material has better compatibility with phase change materials such as paraffin, and also facilitates the uniform dispersion of ceramic particles to ensure the stability of phase change microcapsules.

[0177] See also Fig.11 and Fig.12 Another embodiment of the present application further provides a battery 30, which includes any of the above-mentioned composite thermal insulation pads 10.

[0178] Furthermore, the battery 30 further includes a plurality of battery cells 20, and the composite thermal insulation pad 10 is disposed between at least two adjacent battery cells 20. Optionally, a composite thermal insulation pad 10 is disposed between any two adjacent battery cells 20.

[0179] 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.

[0180] 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 thermal insulation layer (the first thermal insulation layer 121 and / or the second thermal insulation layer 122) of the composite thermal insulation pad 10, and the other side is used to bond the composite thermal 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.

[0181] The battery 30 is provided with the above-mentioned composite thermal insulation pad 10, and its working principle is as follows: In the first stage, after a battery cell 20 in the battery 30 has thermal runaway, the heat is transferred to the adjacent (for example, adjacent) composite thermal insulation pad 10, and the phase change material layer 110 in the composite thermal insulation pad 10 absorbs the heat to achieve the effect of slowing down the thermal runaway of the battery. In the second stage, the phase change material layer 110 absorbs heat until a phase change occurs, absorbing a large amount of heat. In the third stage, the first packaging layer 131 and the phase change material layer 110 fail: the phase change material in the phase change material layer 110 is converted into a gaseous state and breaks through the first packaging layer 131, discharging the high-temperature gas. In the fourth stage, the first thermal insulation layer 121 and the second thermal insulation layer 122 and the optional thermal insulation substrate in the phase change material layer 110 continue to play a role in thermal insulation.

[0182] Among them, the first stage and the second stage are the states before the composite thermal insulation pad 10 fails, and the third stage and the fourth stage are the states after the composite thermal insulation pad 10 fails.

[0183] 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 .

[0184] 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.

[0185] Furthermore, the composite thermal insulation pad 10 is disposed between the large surfaces of two adjacent battery cells 20 .

[0186] 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.

[0187] It is understandable that after a plurality of battery cells 20 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, a plurality of battery cells 20 can be first formed into a battery module, and then a plurality of 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.

[0188] For example, FIG13 is a square-structured battery cell 20 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.

[0189] 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.

[0190] Furthermore, one or both ends of the housing 21 are provided with an opening.

[0191] 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.

[0192] 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.

[0193] As a further non-limiting example, the wall thickness of the shell is 0.5 mm to 0.8 mm.

[0194] Furthermore, the shell is an aluminum alloy shell; for example, a three-series aluminum alloy shell or a five-series aluminum alloy shell.

[0195] 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%.

[0196] 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%.

[0197] 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.

[0198] Fig. 14 shows an example of an electric device 40. The electric device 40 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0199] 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.

[0200] 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.

[0201] 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: A phase change material layer, the phase change material layer comprising a heat insulation substrate and a phase change material filled in the heat insulation substrate; an outer heat-insulating layer, disposed on at least one side of the outer periphery of the phase change material layer; and The encapsulation layer is provided on the outer peripheral side of at least one of the phase change material layer and the outer heat insulating layer.

2. The composite thermal insulation pad according to claim 1, characterized in that: The encapsulation layer comprises a first encapsulation layer, the first encapsulation layer is arranged on the outer peripheral side of the phase change material layer, and the first encapsulation layer and the phase change material layer form a composite phase change layer; The outer heat insulation layer is disposed on at least one side of the outer circumference of the composite phase change layer.

3. The composite thermal insulation pad according to claim 2, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The first packaging layer is an aluminum-plastic film or a polymer packaging film; (2) The thickness of the first encapsulation layer is 0.1 mm to 0.3 mm; (3) The composite thermal insulation pad further includes an adhesive layer, and the outer thermal insulation layer and the first packaging layer are connected via the adhesive layer; (4) The thickness of the composite phase change layer is 1 mm to 6 mm; (5) The thickness of the phase change material layer accounts for 70% to 96% of the total thickness of the composite phase change layer; (6) The thickness ratio of the composite phase change layer to the outer heat insulation layer is 0.15 to 12:1; (7) The length and width of the outer heat insulation layer are respectively adapted to the length and width of the composite phase change layer; or, at least one of the length and width of the outer heat insulation layer is greater than the corresponding length or width of the composite phase change layer.

4. The composite thermal insulation pad according to any one of claims 1 to 3, characterized in that: The encapsulation layer comprises a second encapsulation layer, the second encapsulation layer is arranged on the outer peripheral side of the outer heat insulation layer, and the second encapsulation layer and the outer heat insulation layer form an encapsulation heat insulation layer; The packaging heat-insulating layer is disposed on at least one side of the outer circumference of the phase-change material layer.

5. The composite thermal insulation pad according to claim 4, characterized in that: The second packaging layer has a second packaging margin portion, and the second packaging margin portion is folded and located between the packaging heat insulation layer and the phase change material layer.

6. The composite thermal insulation pad according to claim 4, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The second packaging layer is an aluminum-plastic film or a polymer packaging film; (2) The thickness of the second packaging layer is 0.05 mm to 0.1 mm.

7. The composite thermal insulation pad according to any one of claims 1 to 3, 5 to 6, characterized in that: The encapsulation layer includes a third encapsulation layer, and the third encapsulation layer is disposed on a common outer peripheral side of the phase change material layer and the outer heat insulation layer.

8. The composite thermal insulation pad according to claim 7, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The third encapsulation layer is a polymer encapsulation film; (2) The thickness of the third packaging layer is 0.05 mm to 0.1 mm.

9. The composite thermal insulation pad according to any one of claims 1 to 3, 5 to 6, characterized in that: The outer heat insulation layer is provided with a hollow cavity, and a solid phase change material is provided in the hollow cavity.

10. The composite thermal insulation pad according to any one of claims 1 to 3, 5 to 6, characterized in that: The outer heat insulating layer is disposed on at least one of two sides of the phase change material layer in a thickness direction.

11. The composite thermal insulation pad according to claim 2, characterized in that: The outer heat insulation layer includes a first heat insulation layer and a second heat insulation layer; The first heat insulation layer and the second heat insulation layer are respectively arranged on both sides of the phase change material layer in a thickness direction, so that the phase change material layer is sandwiched between the first heat insulation layer and the second heat insulation layer.

12. The composite thermal insulation pad according to claim 11, 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 composite phase-change 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 3, 5 to 6, characterized in that: The composite thermal insulation pad also includes a first packaging frame and a second packaging frame. The first packaging frame and the second packaging frame can cooperate with each other and fix the phase change material layer, the outer thermal insulation layer and the packaging 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 phase change material layer, the outer heat insulation layer and the packaging layer are limited in a limiting space formed by the first limiting groove and the second limiting groove.

16. The composite thermal insulation pad according to any one of claims 1 to 3 and 5 to 6, characterized in that: The composite thermal insulation pad meets at least one of the following conditions: (1) The outer insulation layer is a ceramic material layer; (2) The thickness of the outer insulation layer is 0.5 mm to 8 mm; (3) The composite thermal insulation pad also includes a release adhesive layer, and the release adhesive layer includes an adhesive layer and a release film. The adhesive layer is arranged on the outer surface of the outer thermal insulation layer, and the release film is arranged on the outer surface of the adhesive layer.

17. A battery, characterized in that: Comprising the composite thermal insulation pad as described in any one of claims 1 to 16.

18. The battery according to claim 17, characterized in that It also includes a plurality of battery cells, and the composite thermal insulation pad is arranged between at least two adjacent battery cells.

19. The battery according to claim 18, characterized in that The composite heat-insulating pad is arranged between the large surfaces of two adjacent battery cells.

20. An electrical device, characterized in that: Comprising a battery as claimed in any one of claims 17 to 19.

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