Battery and electrical apparatus

Abstract

The present invention relates to a battery and an electrical apparatus. The battery comprises a battery cell, and a composite heat insulation pad disposed on at least one side of the battery cell; the composite heat insulation pad comprises a first heat insulation layer, a composite phase change layer, and a second heat insulation layer which are arranged in a stacked manner, the composite phase change layer comprising a phase change material layer, and a packaging layer disposed surrounding the phase change material layer; the thickness of the composite phase change layer is 1 mm to 4 mm, and the thicknesses of each of the first heat insulation layer and the second heat insulation layer are independently 1 mm to 3 mm. Due to the stacked arrangement structure and thickness optimization of the first heat insulation layer, the composite phase change layer and the second heat insulation layer of the composite heat insulation pad, a better heat insulation effect is obtained, and the battery applying said composite heat insulation pad has good resistance to thermal runaway.

Description

Battery and electric device

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 2024202901603 filed on February 8, 2024, and entitled "Battery and electric device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, in particular to a battery and an electric device. BACKGROUND

[0004] With the rapid development of new energy technology, batteries are increasingly widely used in many fields, and people's requirements for battery performance are also increasingly high. For example, higher and higher requirements are put forward for the energy density of the battery.

[0005] However, the residual energy of a battery cell with high energy density is large after thermal runaway, and when one of the battery cells thermally runs away, the heat will continue to conduct from one battery cell to the adjacent battery cell, thereby triggering thermal diffusion of the entire battery, causing serious damage to the entire battery. Therefore, how to slow down the battery thermal runaway is a problem to be solved.

[0006] SUMMARY

[0007] Therefore, it is necessary to provide a battery and an electric device for solving the problem of how to slow down the battery thermal runaway.

[0008] In a first aspect, the present application provides a battery, comprising a battery cell and a composite thermal insulation pad arranged on at least one side of the battery cell, the composite thermal insulation pad comprising a first thermal insulation layer, a composite phase change layer and a second thermal insulation layer arranged in layers, the composite phase change layer comprising a phase change material layer and an encapsulation layer arranged on the outer peripheral side of the phase change material layer, the thickness of the composite phase change layer being 1mm-4mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer being independently 1mm-3mm.

[0009] The battery with the composite thermal insulation pad has the following advantages. The composite thermal insulation pad has the first thermal insulation layer and the second thermal insulation layer, and the composite phase change layer arranged between the first thermal insulation layer and the second thermal insulation layer can absorb heat transferred from the two thermal insulation layers, so that the thermal insulation performance of the composite thermal insulation pad is further improved. The phase change material layer is arranged in the packaging layer, so that the phase change material layer in the composite phase change layer is physically isolated from the thermal insulation layer outside, and the phase change material will not diffuse into the thermal insulation layer to form a heat conduction path before the packaging layer fails, so that the structure of the thermal insulation layer and the thermal insulation performance thereof will not be changed. Meanwhile, the thicknesses of the first thermal insulation layer, the second thermal insulation layer and the composite phase change layer of the composite thermal insulation pad are optimized, so that the composite thermal insulation pad can have good thermal insulation performance at a relatively low thickness. The battery with the composite thermal insulation pad has good effects of preventing and delaying thermal runaway of the battery.

[0010] In some embodiments, the battery satisfies at least one of the following conditions:

[0011] (1) the thickness of the composite phase change layer is 1.5 mm to 3.5 mm;

[0012] (2) the thickness of each of the first thermal insulation layer and the second thermal insulation layer is independently 1 mm to 2.5 mm.

[0013] In some embodiments, the battery monomer is a ternary lithium battery, the thickness of the composite phase change layer is 1.5 mm to 3.3 mm, and the thickness of each of the first thermal insulation layer and the second thermal insulation layer is independently 1 mm to 2.5 mm.

[0014] In some embodiments, the atomic percentage of nickel element in the ternary positive electrode material in the battery monomer is > 0 and < 50%, and the thickness of each of the first thermal insulation layer and the second thermal insulation layer is independently 1 mm to 2 mm.

[0015] In some embodiments, the battery satisfies one of the following conditions:

[0016] (1) the capacity of the battery monomer is < 120 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of each of the first thermal insulation layer and the second thermal insulation layer is independently 1 mm to 1.5 mm;

[0017] (2) the capacity of the battery monomer is ≥ 120 Ah and < 215 Ah, the thickness of the composite phase change layer is 2.3 mm, and the thickness of each of the first thermal insulation layer and the second thermal insulation layer is independently 1.5 mm to 2 mm;

[0018] (3) the capacity of the battery cell is ≥ 215 Ah and < 260 Ah, the thickness of the composite phase change layer is 3.3 mm, and the thickness of the first and second thermal insulation layers is each independently 1.5 mm to 2 mm.

[0019] In some embodiments, the atomic percentage of nickel element in ternary positive electrode material in the battery cell is ≥ 50% and < 70%, the thickness of the composite phase change layer is 2.3 mm to 3.3 mm, and the thickness of the first and second thermal insulation layers is each independently 1.5 mm to 2 mm.

[0020] In some embodiments, the battery satisfies one of the following conditions:

[0021] (1) the capacity of the battery cell is < 150 Ah, and the thickness of the first and second thermal insulation layers is each independently 1.5 mm;

[0022] (2) the capacity of the battery cell is ≥ 150 Ah and < 200 Ah, the thickness of the composite phase change layer is 3.3 mm, and the thickness of the first and second thermal insulation layers is each independently 1.5 mm to 2 mm;

[0023] (3) the capacity of the battery cell is ≥ 200 Ah and < 260 Ah, and the thickness of the first and second thermal insulation layers is each independently 1.5 mm to 2 mm.

[0024] In some embodiments, the atomic percentage of nickel element in ternary positive electrode material in the battery cell is ≥ 70%.

[0025] In some embodiments, the battery satisfies one of the following conditions:

[0026] (1) the capacity of the battery cell is < 100 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first and second thermal insulation layers is each independently 1 mm to 1.5 mm;

[0027] (2) the capacity of the battery cell is ≥ 100 Ah and < 120 Ah, the thickness of the composite phase change layer is 2.3 mm to 3.3 mm, and the thickness of the first and second thermal insulation layers is each independently 1 mm to 1.5 mm;

[0028] (3) the capacity of the battery cell is ≥ 120 Ah, the thickness of the composite phase change layer is 2.3 mm to 3.3 mm, and the thickness of the first and second thermal insulation layers is each independently 2 mm to 2.5 mm.

[0029] In some embodiments, the battery cell is a lithium iron phosphate battery, the thickness of the composite phase change layer is 1.5mm-3.3mm, and the thickness of the first and second thermal insulation layers is independently 1mm-2mm.

[0030] In some embodiments, the battery satisfies one of the following conditions:

[0031] (1) the capacity of the battery cell is <160Ah, the thickness of the composite phase change layer is 1.5mm, and the thickness of the first and second thermal insulation layers is independently 1mm-1.5mm;

[0032] (2) the capacity of the battery cell is ≥160Ah and <260Ah, the thickness of the composite phase change layer is 1.5mm-2.3mm, and the thickness of the first and second thermal insulation layers is independently 1mm-1.5mm;

[0033] (3) the capacity of the battery cell is ≥260Ah and <450Ah, the thickness of the composite phase change layer is 2.3mm-3.3mm, and the thickness of the first and second thermal insulation layers is independently 1.5mm-2mm.

[0034] In some embodiments, the battery cell is a sodium ion battery, the thickness of the composite phase change layer is 1.5mm-2.3mm, and the thickness of the first and second thermal insulation layers is independently 1mm-2mm.

[0035] In some embodiments, the battery satisfies one of the following conditions:

[0036] (1) the capacity of the battery cell is <93Ah, the thickness of the composite phase change layer is 1.5mm, and the thickness of the first and second thermal insulation layers is independently 1mm-1.5mm;

[0037] (2) the capacity of the battery cell is ≥93Ah and <117Ah, and the thickness of the first and second thermal insulation layers is independently 1mm-1.5mm;

[0038] (3) the capacity of the battery cell is ≥117Ah and <180Ah, the thickness of the composite phase change layer is 1.5mm, and the thickness of the first and second thermal insulation layers is independently 1.5mm-2mm.

[0039] In some embodiments, the battery cell is a plurality, and the composite thermal insulation pad is arranged between at least two adjacent battery cells.

[0040] In some embodiments, the composite thermal insulation pad is arranged between large faces of two adjacent battery cells.

[0041] In some embodiments, edges of the first thermal insulation layer and the second thermal insulation layer are connected to each other to form an assembly cavity, and the composite phase change layer is located in the assembly cavity.

[0042] In some embodiments, edges of at least one side surface of at least one of the first thermal insulation layer and the second thermal insulation layer form a protrusion, and the protrusion encloses at least part of the assembly cavity.

[0043] In some embodiments, the composite thermal insulation pad further comprises a first packaging frame and a second packaging frame, the first packaging frame is arranged on one side of the first thermal insulation layer, the second packaging frame is arranged on one side of the second thermal insulation layer, and the first packaging frame and the second packaging frame cooperate to fix the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer.

[0044] In some embodiments, the first packaging frame has a first limiting groove, the second packaging frame has a second limiting groove, and the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer are limited in a limiting space formed by the first limiting groove and the second limiting groove.

[0045] In some embodiments, the composite thermal insulation pad satisfies at least one of the following conditions:

[0046] (1) The composite thermal insulation pad further comprises a first adhesive layer and a second adhesive layer, the first thermal insulation layer and the packaging layer are connected by the first adhesive layer, and the second thermal insulation layer and the packaging layer are connected by the second adhesive layer.

[0047] (2) The composite thermal insulation pad further comprises a release adhesive layer, the release adhesive layer comprises a third adhesive layer and a release film, the third adhesive layer is arranged on the outer surface of the first thermal insulation layer and the second thermal insulation layer, and the release film is arranged on the outer surface of the third adhesive layer.

[0048] (3) The first thermal insulation layer and the second thermal insulation layer comprise a ceramic material layer.

[0049] (4) The packaging layer comprises an aluminum plastic film or a polymer packaging film.

[0050] (5) The thickness of the packaging layer is 0.1mm-0.3mm.

[0051] In some embodiments, the battery cell comprises a shell; and the shell satisfies at least one of the following features:

[0052] (1) The wall thickness of the shell is 0.5mm-0.8mm.

[0053] (2) the shell is a cuboid shell;

[0054] (3) the shell is an aluminum alloy shell.

[0055] In some embodiments, the battery cell includes a shell, the shell is a cuboid shell, the shell has an opening, the opening direction of the shell is the height direction of the shell, the height of the shell is 80mm-210mm, the length of the shell is 90mm-240mm, and the width of the shell is 20mm-80mm.

[0056] In a second aspect, the application provides a power consumption device including the battery as described above.

[0057] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the application or in the prior art, the accompanying drawings needed to be used in the embodiments or the description of the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the disclosed drawings without any creative effort.

[0059] FIG. 1 is a structural schematic diagram of a battery according to an embodiment of the application;

[0060] FIG. 2 is an exploded structural schematic diagram of a battery according to an embodiment of the application;

[0061] FIG. 3 is a cross-sectional structural schematic diagram of a composite thermal insulation pad according to an embodiment of the application;

[0062] FIG. 4 is a cross-sectional structural schematic diagram of a composite thermal insulation pad according to another embodiment of the application;

[0063] FIG. 5 is a cross-sectional structural schematic diagram of a composite thermal insulation pad according to another embodiment of the application;

[0064] FIG. 6 is a cross-sectional structural schematic diagram of a composite thermal insulation pad according to another embodiment of the application;

[0065] FIG. 7 is a three-dimensional structural schematic diagram of a composite thermal insulation pad according to another embodiment of the application;

[0066] FIG. 8 is a cross-sectional schematic diagram of the composite thermal insulation pad shown in FIG. 7 in the A-A direction;

[0067] FIG. 9 is a cross-sectional exploded view of the composite thermal insulation pad shown in FIG. 8;

[0068] Fig. 10 is a schematic view of a cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0069] Fig. 11 is a schematic view of a structure of a battery cell in a battery according to an embodiment;

[0070] Fig. 12 is a schematic view of an electric device using a battery as a power source according to an embodiment of the present application;

[0071] Fig. 13 is a graph of a measured curve and a simulation curve of a heat estimation model of a thermal insulation performance of the battery 2 in Example 1;

[0072] Fig. 14 is a graph of a measured curve and a simulation curve of a heat estimation model of a thermal insulation performance of the battery 3 in Example 1;

[0073] Fig. 15 is a flowchart of a test method according to an embodiment;

[0074] Fig. 16 is a schematic view of an internal structure of a computer device according to an embodiment.

[0075] Reference Signs: 10, composite thermal insulation pad; 11, first thermal insulation layer; 12, second thermal insulation layer; 13, composite phase change layer; 131, phase change material layer; 132, encapsulation layer; 1321, encapsulation frame; 141, first encapsulation frame; 142, second encapsulation frame; 151, first adhesive layer; 152, second adhesive layer; 16, third thermal insulation layer; 20, battery cell; 21, shell; 22, electrode assembly; 23, cover plate; 30, battery; 40, electric device. DETAILED DESCRIPTION

[0076] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many different ways from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, and thus the present application is not limited to the specific embodiments disclosed below.

[0077] In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0078] In addition, if the terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0079] In the present application, unless otherwise explicitly specified and limited, if the first feature appears "on" or "under" the second feature, etc. similar description, the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0080] It should be noted that if an element is referred to as "fixed to" or "provided on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for the purpose of illustration, and do not represent the only implementation.

[0081] "Ranges" disclosed herein are defined, for each specific range by a lower and an upper limit, defining the range's boundaries. Such ranges can be inclusive or exclusive of the end values, and are arbitrarily combinable, i.e., any lower limit can be combined with any upper limit to create a range. For example, if ranges of 60-120 and 80-110 are listed, it is understood that ranges of 60-110 and 80-120 are also contemplated. Further, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise indicated, a numerical range "a-b" indicates a shorthand way of describing each and every number that is an integer within the given range of a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shorthand way of describing those numerical combinations. Additionally, when a parameter is stated to be an integer > 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0082] At present, from the development of market situation, the application of battery is more and more extensive. The battery, especially the power battery, is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric vehicles and other fields. With the continuous expansion of the application field of power battery, the market demand is also increasing.

[0083] The battery monomer is the smallest unit to constitute the battery. One battery can include one or more battery monomers, and the plurality of battery monomers can be connected in series or in parallel or in mixed connection. The mixed connection means that there are series connection and parallel connection between the plurality of battery monomers.

[0084] After the plurality of battery monomers are connected to each other and arranged in a certain order, they can be directly accommodated in the box to form the battery. Alternatively, the plurality of battery monomers can be first combined to form a battery module, and then the plurality of battery modules are connected to each other to form a whole, and finally the whole of the battery module is accommodated in the box to form the battery.

[0085] In order to solve the above-mentioned battery thermal runaway problem and reduce the damage degree and risk to the whole battery, the application provides a battery applied with a composite thermal insulation pad, and the film thickness of the composite thermal insulation pad is optimized to obtain a better thermal insulation effect. Further, based on the different systems of the battery monomers, the film thickness of the composite thermal insulation pad is further optimized based on the different capacities of the battery monomers, so as to obtain a better thermal insulation effect.

[0086] Referring to FIG. 1 and FIG. 2, an embodiment of the present application provides a battery 30 comprising a battery cell 20 and a composite thermal insulation pad 10 arranged on at least one side of the battery cell 20.

[0087] Referring to FIG. 3, the composite thermal insulation pad 10 comprises a first thermal insulation layer 11, a composite phase change layer 13 and a second thermal insulation layer 12 arranged in a stack. The composite phase change layer 13 comprises a phase change material layer 131 and an encapsulation layer 132 arranged on the outer circumferential side of the phase change material layer 131. The thickness of the composite phase change layer 13 is 1mm-4mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1mm-3mm.

[0088] The battery 30 with the composite thermal insulation pad 10 described above, wherein the composite thermal insulation pad 10 is provided with the first thermal insulation layer 11 and the second thermal insulation layer 12 at the same time, and can play a good thermal insulation effect; on the other hand, the composite phase change layer 13 arranged between the first thermal insulation layer 11 and the second thermal insulation layer 12 can absorb the heat transferred from the two sides of the thermal insulation layer, so as to further improve the thermal insulation performance of the composite thermal insulation pad 10. The phase change material layer 131 is arranged in the encapsulation layer 132, so that the phase change material layer 131 in the composite phase change layer 13 is physically isolated from the thermal insulation layer outside, and the phase change material will not diffuse into the thermal insulation layer to form a heat conduction path before the encapsulation layer 132 fails, so as not to change the structure of the thermal insulation layer and its thermal insulation performance, so that the composite thermal insulation pad 10 described above has good thermal insulation performance. At the same time, the thickness of the first thermal insulation layer 11, the second thermal insulation layer 12 and the composite phase change layer 13 of the composite thermal insulation pad 10 is optimized, so that the composite thermal insulation pad 10 can obtain better thermal insulation effect at a lower thickness. The battery with the composite thermal insulation pad 10 has a good effect of resisting and delaying battery thermal runaway.

[0089] The battery 30 with the composite thermal insulation pad 10 described above, when the battery 30 is in a normal working state, the first thermal insulation layer 11 and the second thermal insulation layer 12 located outside mainly play a thermal insulation effect; when the battery 30 abnormally generates heat and a large amount of heat is conducted to the phase change material layer 131 in the composite phase change layer 13, the phase change material layer 131 can absorb a large amount of heat and then undergo phase change; when the phase change material layer 131 continues to absorb heat, the phase change material in it is converted into a gaseous state and breaks the encapsulation layer 132, and the high-temperature gas is discharged to cause the encapsulation of the encapsulation layer 132 to fail, at which time the first thermal insulation layer 11 and the second thermal insulation layer 12 continue to play a thermal insulation effect.

[0090] In the present application, the "battery cell" refers to a basic unit capable of realizing the mutual conversion of chemical energy and electrical energy, and further generally includes at least a positive electrode sheet, a negative electrode sheet, and an electrolyte. During the charging and discharging process of the battery, active ions are embedded and de-embedded between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting active ions between the positive electrode sheet and the negative electrode sheet.

[0091] As an example, the thickness of the composite phase change layer 13 can be 1 mm, 1.5 mm, 2 mm, 2.3 mm, 2.5 mm, 3 mm, 3.5 mm. It can be understood that the thickness of the composite phase change layer 13 refers to the sum of the thickness of the encapsulation layer 132 on both sides and the thickness of the phase change material layer 131 in the film layer stacking direction of the composite thermal insulation pad 10, i.e. the thickness direction. In some embodiments, the thickness can also be a range composed of any two of the above point values as end values, similarly below, for example, 1.5 mm to 3.5 mm.

[0092] As an example, the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1 mm, 1.5 mm, 2 mm, 2.3 mm, 2.5 mm. In some embodiments, the thickness can also be 1 mm to 2.5 mm.

[0093] Further, based on the system of the battery cell 20, the film layer thickness of the composite thermal insulation pad 10 is optimized to obtain a better thermal insulation effect. The system of the battery cell 20 includes ternary lithium battery (referred to as ternary in Table 1), lithium iron phosphate battery (LFP battery), and sodium ion battery (sodium). The specific values are shown in Table 1 as follows.

[0094] Table 1

[0095] Referring to Table 1, in some embodiments, the battery cell 20 is a ternary lithium battery, the thickness of the composite phase change layer 13 is 1.5 mm to 3.3 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1 mm to 2.5 mm.

[0096] The ternary lithium battery further optimizes the film layer thickness of the composite thermal insulation pad 10 based on the different nickel content in the ternary positive electrode material, thereby obtaining a better thermal insulation effect. It can be understood that the Ni content in the ternary positive electrode material in Table 1 refers to the atomic percentage of nickel element in ternary elements. For example, NCM 811 Taking the ternary positive electrode material as an example, the nickel content refers to the atomic percentage of nickel element in nickel-cobalt-manganese ternary elements, i.e. 80%.

[0097] The ternary cathode material in the present application contains a nickel element, which includes but is not limited to at least one of lithium nickel cobalt manganese oxide (hereinafter referred to as "NCM") or lithium nickel cobalt aluminum oxide (hereinafter referred to as "NCA"). Non-limiting examples of lithium nickel cobalt manganese oxide (NCM) can include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also referred to as NCM 811 ), etc. Non-limiting examples of lithium nickel cobalt aluminum oxide (NCA) can include LiNi 0.8 Co 0.15 Al 0.05 O2.

[0098] In some embodiments, the atomic percentage of the nickel element in the ternary cathode material in the battery cell 20 is > 0 and < 50% of the ternary element, and the ternary cathode material is generally considered to be a low-nickel ternary system; the thickness of the composite phase change layer 13 is 1.5 mm to 3.3 mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1 mm to 2 mm.

[0099] Further, in the case of the same battery cell 20 system, the present application optimizes the film layer thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cell 20, thereby obtaining a better thermal insulation effect. Specifically, the battery cell 20 is a ternary lithium battery, the atomic percentage of the nickel element in the ternary cathode material in the battery cell 20 is > 0 and < 50% of the ternary element, and based on the different capacities of the battery cell 20, there are three schemes as follows (1) to (3).

[0100] (1) The capacity of the battery cell 20 is < 120 Ah, the thickness of the composite phase change layer 13 is 1.5 mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1 mm to 1.5 mm.

[0101] (2) the capacity of the battery monomer 20 is ≥ 120 Ah and < 215 Ah, the thickness of the composite phase change layer 13 is 2.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm-2 mm.

[0102] (3) the capacity of the battery monomer 20 is ≥ 215 Ah and < 260 Ah, the thickness of the composite phase change layer 13 is 3.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm-2 mm.

[0103] Therefore, as the capacity of the battery monomer 20 increases, the thickness of the composite phase change layer 13 is increased accordingly, which can significantly improve the heat insulation effect of the composite heat insulation pad 10; in addition, compared with a simple heat insulation layer, the heat insulation effect of the composite heat insulation pad 10 of the present application is greatly improved under the same total thickness, thereby facilitating the reduction of the battery occupied volume.

[0104] In some embodiments, the atomic proportion of nickel element in the ternary positive electrode material in the battery monomer 20 accounts for ≥ 50% and < 70% of the ternary element, and the ternary positive electrode material is generally considered as a medium-nickel ternary system; the thickness of the composite phase change layer 13 is 2.3 mm-3.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm-2.5 mm.

[0105] Further, under the same battery monomer 20 system, the film layer thickness of the composite heat insulation pad 10 is optimized based on the different capacity of the battery monomer 20, thereby obtaining a better heat insulation effect. Specifically, the battery monomer 20 is a ternary lithium battery, the atomic proportion of nickel element in the ternary positive electrode material in the battery monomer 20 accounts for ≥ 50% and < 70% of the ternary element, and based on the different capacity of the battery monomer 20, there are three schemes as follows (1)-(3).

[0106] (1) the capacity of the battery monomer 20 is < 150 Ah, the thickness of the composite phase change layer 13 is 2.3 mm-3.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm.

[0107] (2) the capacity of the battery monomer 20 is ≥ 150 Ah and < 200 Ah, the thickness of the composite phase change layer 13 is 2.3 mm-3.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm-2 mm.

[0108] (3) the capacity of the battery monomer 20 is ≥ 200 Ah and < 260 Ah, the thickness of the composite phase change layer 13 is 2.3 mm-3.3 mm, and the thickness of the first heat insulation layer 11 and the second heat insulation layer 12 is independently 1.5 mm-2.5 mm.

[0109] Further, in the case of the same battery monomer 20 system, the application optimizes the film layer thickness of the composite thermal insulation pad 10 based on the different capacities of the battery monomer 20, thereby obtaining a better thermal insulation effect. The nickel element of the ternary positive electrode material in the battery monomer 20 accounts for ≥70% of the atomic proportion of ternary elements, and generally this ternary positive electrode material is considered to be a high-nickel ternary system, and the proportion of nickel is <100%; the thickness of the composite phase change layer 13 is 1.5mm-3.3mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1mm-2.5mm.

[0110] Further, in the case of the same battery monomer 20 system, the application optimizes the film layer thickness of the composite thermal insulation pad 10 based on the different capacities of the battery monomer 20, thereby obtaining a better thermal insulation effect. Specifically, the battery monomer 20 is a ternary lithium battery, the nickel element of the ternary positive electrode material in the battery monomer 20 accounts for ≥70% of the atomic proportion of ternary elements, and based on the different capacities of the battery monomer 20, there are three schemes as follows (1)-(3).

[0111] (1) The capacity of the battery monomer 20 is <100Ah, the thickness of the composite phase change layer 13 is 1.5mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1mm-1.5mm;

[0112] (2) The capacity of the battery monomer 20 is ≥100Ah and <120Ah, the thickness of the composite phase change layer 13 is 2.3mm-3.3mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1mm-1.5mm;

[0113] (3) The capacity of the battery monomer 20 is ≥120Ah, the thickness of the composite phase change layer 13 is 2.3mm-3.3mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 2mm-2.5mm.

[0114] (1) and (2), as the capacity of the battery monomer 20 increases, the thermal insulation effect of the composite thermal insulation pad 10 can be significantly improved by increasing the thickness of the composite phase change layer 13; in addition, compared with a simple thermal insulation layer, the thermal insulation effect of the composite thermal insulation pad 10 of the application is greatly improved under the same total thickness, thereby facilitating the reduction of the battery occupying volume. In (2) and (3), as the capacity of the battery monomer 20 continues to increase, the cost of continuing to increase the thickness of the composite phase change layer 13 is too high and the effect is not obvious, at this time the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 can be further increased, thereby improving the thermal insulation effect of the composite thermal insulation pad 10.

[0115] In some embodiments, the battery cell 20 is a lithium iron phosphate battery, the thickness of the composite phase change layer 13 is 1.5mm-3.3mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1mm-2mm.

[0116] Further, in the case of the same battery cell 20 system, the application optimizes the film layer thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cell 20, thereby obtaining a better thermal insulation effect. Specifically, the battery cell 20 is a lithium iron phosphate battery, and based on the different capacities of the battery cell 20, there are three schemes as follows (1)-(3).

[0117] (1) The capacity of the battery cell 20 is <160Ah, the thickness of the composite phase change layer 13 is 1.5mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1mm-1.5mm.

[0118] (2) The capacity of the battery cell 20 is ≥160Ah and <260Ah, the thickness of the composite phase change layer 13 is 1.5mm-2.3mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1mm-1.5mm.

[0119] (3) The capacity of the battery cell 20 is ≥260Ah and <450Ah, the thickness of the composite phase change layer 13 is 2.3mm-3.3mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1.5mm-2mm.

[0120] In (1) and (2), as the capacity of the battery cell 20 increases, the thermal insulation effect of the composite thermal insulation pad 10 can be significantly improved by increasing the thickness of the composite phase change layer 13; in addition, compared with a simple thermal insulation layer, the thermal insulation effect of the composite thermal insulation pad 10 of the application is greatly improved under the same total thickness, thereby facilitating the reduction of the battery occupied volume. In (2) and (3), as the capacity of the battery cell 20 continues to increase, the thickness of the composite phase change layer 13, the first and second thermal insulation layers 11 and 12 can be further increased, thereby improving the thermal insulation effect of the composite thermal insulation pad 10.

[0121] In some embodiments, the battery cell 20 is a sodium ion battery, the thickness of the composite phase change layer 13 is 1.5mm-2.3mm, and the thickness of the first and second thermal insulation layers 11 and 12 is independently 1mm-2mm.

[0122] The sodium-ion battery contains a sodium-ion active material. As a non-limiting example of the sodium-ion active material, the sodium-ion active material can include one or more of the following materials: one or more of sodium transition metal oxides, polyanion-type compounds, and Prussian blue-type compounds. However, the present application is not limited to these materials, and other conventionally known materials that can be used as a positive electrode active material for a sodium-ion battery can also be used.

[0123] Further, in the case of the same battery cell 20 system, the present application optimizes the film layer thickness of the composite thermal insulation pad 10 based on the capacity difference of the battery cell 20, thereby obtaining a better thermal insulation effect. Specifically, the battery cell 20 is a sodium-ion battery, and based on the capacity difference of the battery cell 20, there are three schemes as follows (1) to (3).

[0124] (1) The capacity of the battery cell 20 is < 93 Ah, the thickness of the composite phase change layer 13 is 1.5 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1 mm to 1.5 mm.

[0125] (2) The capacity of the battery cell 20 is ≥ 93 Ah and < 117 Ah, the thickness of the composite phase change layer 13 is 1.5 mm to 2.3 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1 mm to 1.5 mm.

[0126] (3) The capacity of the battery cell 20 is ≥ 117 Ah and < 180 Ah, the thickness of the composite phase change layer 13 is 1.5 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 is independently 1.5 mm to 2 mm.

[0127] In (1) and (2), as the capacity of the battery cell 20 increases, the thermal insulation effect of the composite thermal insulation pad 10 can be significantly improved by increasing the thickness of the composite phase change layer 13; in addition, compared with a simple thermal insulation layer, the thermal insulation effect of the composite thermal insulation pad 10 of the present application is greatly improved under the same total thickness, thereby facilitating the reduction of the battery occupied volume. In (2) and (3), as the capacity of the battery cell 20 continues to increase, the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 can be further increased, thereby improving the thermal insulation effect of the composite thermal insulation pad 10.

[0128] The conventional technology is limited in structure, and the phase change material can only be a solid phase change material, but the heat absorption capacity of the solid phase change material is limited. The composite thermal insulation pad 10 has the phase change material layer 131 arranged in the packaging cavity of the packaging layer 132, so that the phase change material layer 131 is physically isolated from the outer thermal insulation layer. Therefore, the phase change material of the phase change material layer 131 can be a solid phase change material, a liquid phase change material, or a solid-liquid mixed phase change material. Optionally, the phase change material includes but is not limited to crystalline water and salt, phase change molten salt, paraffin, silicone oil, silica sol, fatty acid, alcohol, and other substances that can undergo phase change and heat absorption. The composite thermal insulation pad has a wider application range.

[0129] In addition, because the phase change material of the phase change material layer 131 will undergo phase change, for example, the solid phase change material at room temperature will change to liquid after absorbing heat. Therefore, the packaging layer 132 can also play a role in isolating the phase change material in liquid state from the outer thermal insulation layer. In addition, some preparation processes inevitably cause the phase change material to have moisture. The structure of arranging the phase change material layer 131 in the packaging cavity of the packaging layer 132 can avoid the adverse effects of moisture overflow on the battery.

[0130] Referring to FIG. 4, in some embodiments, the composite thermal insulation pad 10 further includes a first adhesive layer 151 and a second adhesive layer 152. The first thermal insulation layer 11 and the packaging layer 132 are connected by the first adhesive layer 151. The second thermal insulation layer 12 and the packaging layer 132 are connected by the second adhesive layer 152. In this way, the first thermal insulation layer 11, the composite phase change layer 13, and the second thermal insulation layer 12 of the composite thermal insulation pad 10 are connected and fixed in the thickness direction through the adhesive layers.

[0131] Further, the materials of the first adhesive layer 151 and the second adhesive layer 152 are independently silicone adhesive layers, and the thicknesses of the first adhesive layer 151 and the second adhesive layer 152 are independently 0.04-0.06 mm. The silicone adhesive layer has high temperature resistance and high structural strength. The peel strength of the prepared composite thermal insulation pad is greater than 10 N / cm. The peel strength can be measured by using a tensile tester to pull the two sides of the composite thermal insulation pad, using a 90° force perpendicular to the composite thermal insulation pad to act on the two sides of the composite thermal insulation pad, and measuring the tensile force when the composite thermal insulation pad is peeled off. The peel strength can be obtained according to the tensile force.

[0132] 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 arranged on the outer surface of the first thermal insulation layer 11 and the second thermal insulation layer 12, and the release film is arranged on the outer surface of the third adhesive layer. In this way, when it is necessary to fix the composite thermal insulation pad 10 at a target position, for example, a target battery monomer, the release film on the surface of the release adhesive layer of the composite thermal insulation pad 10 is removed, and the composite thermal insulation pad 10 is fixed to the target position by the third adhesive layer in a simple and convenient manner, which can play a role in fixing the composite thermal insulation pad 10.

[0133] As an example, the outer surfaces of the first thermal insulation layer 11 and the second thermal insulation layer 12 of the composite thermal insulation pad 10 are each provided with the release adhesive layer described above. In use, the composite thermal insulation pad 10 can be fixed and bonded to two objects respectively through the release adhesive layers on the two sides, for example, to two battery monomers arranged adjacently respectively, so as to arrange the composite thermal insulation pad 10 between the two battery monomers arranged adjacently.

[0134] As shown in FIG. 4, the first thermal insulation layer 11 and the second thermal insulation layer 12 are physically isolated by the composite phase change layer 13, in other words, the edges between the first thermal insulation layer 11 and the second thermal insulation layer 12 are not connected to each other.

[0135] In some embodiments, the length and width dimensions of the first thermal insulation layer 11 and the second thermal insulation layer 12 are respectively adapted to the length and width dimensions of the composite phase change layer 13. In other embodiments, at least one of the length and width dimensions of the first thermal insulation layer 11 and the second thermal insulation layer 12 is greater than the corresponding length or width dimension of the composite phase change layer 13.

[0136] Referring to FIG. 5, in some embodiments, the edges of the first thermal insulation layer 11 and the second thermal insulation layer 12 are connected to each other to form an assembly cavity, and the composite phase change layer 13 is located in the assembly cavity. Through this structure, the composite phase change layer 13 is arranged inside the first thermal insulation layer 11 and the second thermal insulation layer 12, thereby reducing the risk of the composite phase change layer 13 falling off.

[0137] Further, the edges of at least one side surface of at least one of the first thermal insulation layer 11 and the second thermal insulation layer 12 form a protrusion, and the protrusion encloses at least part of the assembly cavity. As an example, the edges of at least one side surface of both the first thermal insulation layer 11 and the second thermal insulation layer 12 form protrusions, and the protrusions of the two are arranged opposite to each other and enclose the assembly cavity. In the specific example as shown in FIG. 5, the edges of the four side surfaces of one side surface of the first thermal insulation layer 11 and the second thermal insulation layer 12 form protrusions, and the protrusions of the first thermal insulation layer 11 and the second thermal insulation layer 12 are arranged opposite to each other and enclose the assembly cavity.

[0138] Generally, the two sides of the phase change material layer 131 are encapsulated by the encapsulation film, and there are encapsulation left edge portions on the side edges, for example, the encapsulation left edge portion 1321 in FIG. 9 below; that is, the encapsulation layer 132 has encapsulation left edge portions. When the composite phase change layer 13 is arranged inside the first thermal insulation layer 11 and the second thermal insulation layer 12, the encapsulation left edge portions are folded into the assembly cavity.

[0139] As an example, the encapsulation layer 132 has encapsulation left edge portions on all four sides.

[0140] Referring to FIG. 6, in some embodiments, the composite thermal insulation pad 10 further comprises a third thermal insulation layer 16, and the composite phase change layer 13 is arranged between the second thermal insulation layer 12 and the third thermal insulation layer 16. Further, the composite thermal insulation pad 10 can further comprise more thermal insulation layers, and the composite phase change layer 13 can be arranged between adjacent thermal insulation layers.

[0141] Further, the third thermal insulation layer 16 and other thermal insulation layers can be selected from the same range of materials and thicknesses as the first thermal insulation layer 11 and the second thermal insulation layer 12; and the specific materials and specific thicknesses can be the same or different.

[0142] Referring to FIGS. 7 and 8, in some embodiments, the composite thermal insulation pad 10 further comprises a first encapsulation frame 141 and a second encapsulation frame 142, the first encapsulation frame 141 is arranged on one side of the first thermal insulation layer 11, and the second encapsulation frame 142 is arranged on one side of the second thermal insulation layer 12, and the first encapsulation frame 141 and the second encapsulation frame 142 cooperate to fix the first thermal insulation layer 11, the composite phase change layer 13, and the second thermal insulation layer 12.

[0143] Further, the first encapsulation frame 141 and the second encapsulation frame 142 are each independently a rubber frame or a silica gel frame. In other words, the materials of the first encapsulation frame 141 and the second encapsulation frame 142 are each independently rubber or silica gel. Further, the first encapsulation frame 141 and the second encapsulation frame 142 are each a mouth-shaped frame, such as a silica gel mouth-shaped frame.

[0144] In the example shown in FIGS. 8 and 9, 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 11, the composite phase change layer 13, and the second thermal insulation layer 12 are limited in a 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 first thermal insulation layer 11, the composite phase change layer 13, and the second thermal insulation layer 12 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. 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 encapsulation margin part 1321 of the encapsulation layer 132 can be located between the first encapsulation frame 141 and the second encapsulation frame 142, as shown in FIG. 9, the encapsulation margin part 1321 is pressed in the middle by the first encapsulation frame 141 and the second encapsulation frame 142.

[0145] It can be understood that when the first packaging frame 141 and the second packaging frame 142 are provided simultaneously, and the first heat insulation layer 11 and the second heat insulation layer 12 are capable of forming the assembly cavity, the packaging reserved edge part 1321 of the packaging layer 132 can pass between the convex parts of the first heat insulation layer 11 and the second heat insulation layer 12 and be located between the first packaging frame 141 and the second packaging frame 142, or the packaging reserved edge part 1321 of the packaging layer 132 can be folded to be located in the assembly cavity.

[0146] Referring to FIG. 10, in some other embodiments, the outer surface of the first heat insulation layer 11 is flush with the outer surface of the first packaging frame 141, and / or the outer surface of the second heat insulation layer 12 is flush with the outer surface of the second packaging frame 142. In this way, the thickness of the composite heat insulation pad 10 can be minimized, the space occupied by the composite heat insulation pad 10 can be reduced, and better heat insulation performance can be provided.

[0147] For 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 first heat insulation layer 11, the composite phase change layer 13, and the second heat insulation layer 12 around, so as to improve the structural stability of the composite heat insulation pad 10. Further, the packaging frame is not required to fix in the thickness direction at this time, so that the outer surface of the first heat insulation layer 11 can be flush with the outer surface of the first packaging frame 141, and the outer surface of the second heat insulation layer 12 can be flush with the outer surface of the second packaging frame 142.

[0148] It can be understood that in some embodiments, the first heat insulation layer 11, the composite phase change layer 13, the second heat insulation layer 12, and the third heat insulation layer 16 can be connected by using the adhesive layer, or connected by using the packaging frame, or connected by using both the adhesive layer and the packaging frame, or not connected by using the adhesive layer and the packaging frame, for example, the first heat insulation layer 11 is directly formed on the packaging layer 132 of the composite phase change layer 13.

[0149] Further, the first heat insulation layer 11, the second heat insulation layer 12, and the third heat insulation layer 16 each independently include at least one of the heat insulation felt and the heat insulation coating.

[0150] Further, when the heat insulation layer includes both the heat insulation felt and the heat insulation coating, the heat insulation coating can be optionally arranged on the side closer to the composite phase change layer 13, specifically, the heat insulation coating is arranged on the surface of the packaging layer 132 of the composite phase change layer 13, and the heat insulation felt is arranged on the side farther away from the composite phase change layer 13. In other words, the heat insulation coating is directly formed on the surface of the packaging layer 132, and the heat insulation coating is located between the packaging layer 132 and the heat insulation felt.

[0151] For example, in the examples shown in FIG. 3, FIG. 4 and FIG. 6, the first thermal insulation layer 11 and the second thermal insulation layer 12 are both ceramic felt, and the third thermal insulation layer 16 is also ceramic felt. In other examples, the first thermal insulation layer 11 and the second thermal insulation layer 12 can also be thermal insulation coating. In contrast, the thermal insulation coating is thinner, and the overall thickness of the 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 use thermal insulation coating, or a combination of thermal insulation coating and ceramic felt, which can balance the smaller occupied space and better thermal insulation performance.

[0152] For example, in the example shown in FIG. 5, the first thermal insulation layer 11 and the second thermal insulation layer 12 are both ceramic felt, and the assembly cavity thereon can be integrally formed when the ceramic felt is formed, or can be formed by slotting after the ceramic felt is formed.

[0153] It can be understood that the ceramic felt can be connected to the composite phase change layer 13 through the adhesive layer or the packaging frame. The thermal insulation coating can be directly formed on the packaging layer 132 in the composite phase change layer 13. As an example, the thermal insulation coating can be prepared by coating slurry on the packaging layer 132 in the composite phase change layer 13 and then drying.

[0154] Further, the ceramic felt can be a ceramic thermal insulation felt; further, the thermal insulation coating can be a ceramic thermal insulation coating.

[0155] In some embodiments, the first thermal insulation layer 11, the second thermal insulation layer 12 and the third thermal insulation layer 16 each independently satisfy the following conditions: the thermal conductivity at 25°C is ≤0.020 W / m·K, the thermal conductivity at 200°C is ≤0.027 W / m·K, the thermal conductivity at 300°C is ≤0.035 W / m·K, and the thermal conductivity at 500°C is ≤0.080 W / m·K.

[0156] In some embodiments, the density of the first thermal insulation layer 11, the second thermal insulation layer 12 and the third thermal insulation layer 16 is each independently 0.2 g / cm 3 ~0.22 g / cm 3 .

[0157] In this paper, the detection of the thickness of each layer in the composite thermal insulation pad can be carried out by the following method. The equipment used is a Fein 547-301 thickness gauge, and the accuracy of the equipment is ≤0.01 mm; during detection, it is required that the detection surface of the composite thermal insulation pad and the Fein 547-301 thickness gauge are parallel to the ground, and the detection position is at the center of the four corners and the center area, and the average value of the five positions is taken as the detection value.

[0158] In some embodiments, the first thermal insulation layer 11 and the second thermal insulation layer 12 each independently comprise a ceramic material layer.

[0159] In some embodiments, the first thermal insulation layer 11 is a layer of ceramic material.

[0160] In some embodiments, the second thermal insulation layer 12 is a layer of ceramic material.

[0161] In the present application, the material in the "layer of ceramic material" includes but is not limited to at least one of ceramic oxide, ceramic nitride, and ceramic carbide. Among them, the ceramic oxide includes but is not limited to at least one of silicon oxide and aluminum oxide, the ceramic nitride includes but is not limited to silicon nitride, and the ceramic carbide includes but is not limited to silicon carbide.

[0162] In some examples, the layer of ceramic material can be a stack of one or more of a layer of silicon oxide, a layer of aluminum oxide, a layer of silicon nitride, and a layer of silicon carbide.

[0163] Further, the ceramic thermal insulation felt can be a silica aerogel ceramic felt. As an example, the silica aerogel ceramic felt can be prepared by using inorganic fiber reinforcement technology to prepare aerogel material, through sol, gel, solvent replacement and supercritical drying process.

[0164] In some embodiments, the thickness of the encapsulation layer 132 is 0.1mm-0.3mm, for example, it can be 0.1mm, 0.15mm, 0.2mm, 0.3mm, optionally 0.1mm-0.15mm, or 0.2mm-0.3mm.

[0165] In some embodiments, the encapsulation layer 132 includes or is an aluminum-plastic film or a polymer encapsulation film.

[0166] Further, the encapsulation layer 132 includes a polypropylene layer, an aluminum layer, and a nylon layer arranged in a stack from inside to outside.

[0167] Further, the polymer encapsulation film can be a PET film (polyethylene terephthalate film) or a PI film (polyimide film).

[0168] In some embodiments, the encapsulation layer 132 is provided with a weak part on the area constituting the encapsulation cavity. Since the weak part position is a weak area, when the phase change material layer 131 absorbs a large amount of heat, the phase change material in the phase change material layer 131 undergoes phase change to cause the encapsulation layer 132 to bulge, which can make the encapsulation layer 132 timely burst at the weak part position when thermal runaway occurs, further reducing the damage degree of thermal runaway to the whole battery.

[0169] Understandably, the weak part on the encapsulation layer 132 is a relatively weak area on the encapsulation layer 132.

[0170] In some embodiments, a weak portion is an area of ​​relatively thin thickness and / or relatively weak material strength. In other words, a weak portion can be an area of ​​relatively thin thickness but constant material strength, which can be formed by locally thinning the encapsulation layer 132. A weak portion can also be an area of ​​relatively constant thickness but relatively weak material strength, which can be formed by locally weakening the material strength of the encapsulation layer 132, for example, by using materials of different strengths. Alternatively, a weak portion can be an area of ​​relatively thin thickness and relatively weak material strength. It should be understood that the material strength here refers to the strength of the material itself.

[0171] Furthermore, the weak portion is a notch area formed on the encapsulation layer 132. It can be understood that the notch area is formed by thinning the surface of the encapsulation layer 132 in the form of engraving and pressing, and the thickness of the notch area is relatively thin.

[0172] Furthermore, the weak portion may be disposed on the outer side or inner side of the encapsulation layer 132. The outer side refers to the surface of the encapsulation layer 132 away from the phase change material layer 131, and the inner side refers to the surface of the encapsulation layer 132 close to the phase change material layer 131.

[0173] Furthermore, the depth of the weak portion accounts for 15% to 50% of the thickness of the encapsulation layer 132, for example, 15%, 20%, 30%, 35%, 40%, 45%, or 50%. Controlling this thickness ratio allows the encapsulation layer to provide both good isolation when no package breakage is required and good timely package breakage in the event of thermal runaway.

[0174] Furthermore, the aluminum-plastic film includes an aluminum foil layer and plastic film layers arranged on both surfaces of the aluminum foil layer.

[0175] Furthermore, when the encapsulation layer 132 is an aluminum-plastic film, the weak portion extends from the surface of the aluminum-plastic film to 30% to 60% of the thickness of the aluminum foil layer, for example, 30%, 40%, 50%, or 60%. The weak portion is controlled to penetrate the aluminum foil layer without penetrating the aluminum foil layer, and is further controlled to penetrate 30% to 60% of the thickness of the aluminum foil layer. This ensures that the encapsulation layer provides both better isolation when rupture is not necessary and better, more timely rupture in the event of thermal runaway.

[0176] The plastic film layer in the aluminum-plastic film may include, but is not limited to, at least one of a polypropylene layer, a nylon layer, and a polyester layer. In some examples, encapsulation layer 132 includes a polypropylene layer, an aluminum foil layer, a nylon layer, and a polyester layer stacked from the inside out. Specifically, the thicknesses of the polypropylene layer, the aluminum foil layer, the nylon layer, and the polyester layer are 80 μm, 40 μm, 15 μm, and 6 μm, respectively. The weak portion may extend from one side of the polyester layer to half the thickness of the aluminum foil layer.

[0177] In some embodiments, the phase change material layer 131 further comprises a thermal insulation substrate in addition to the phase change material, and at least part of the phase change material is filled in the pores of the thermal insulation substrate. In other words, the pores of the thermal insulation substrate are filled with the phase change material.

[0178] The thermal insulation substrate can be a ceramic material substrate, such as a ceramic fiber felt.

[0179] Further, 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 can be understood that in the same thermal insulation substrate, both types of phase change materials can be included, one of which is directly filled in the pores of the thermal insulation substrate, and the other of which is filled in the pores of the thermal insulation substrate in the form of phase change microcapsules.

[0180] It can be understood that the thermal insulation substrate with pores, such as a ceramic fiber felt, is immersed in a liquid phase change material, such as a molten phase change material after immersion, or dried or heat treated after immersion in a phase change material solution, to obtain the phase change material layer 131. In addition to the function of absorbing heat, the phase change material layer 131 can also have a thermal insulation effect. When the phase change material in the composite thermal insulation pad 10 is gasified and the packaging layer 132 is broken, the thermal insulation substrate in the phase change material layer 131 can continue to have a thermal insulation effect. In other words, the phase change material is directly filled in the pores of the thermal insulation substrate.

[0181] 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 131 can be filled with phase change microcapsules. The phase change microcapsule comprises a core material and a wall material, and the wall material is wrapped on the outer surface of the core material, and the core material comprises 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 material and filled with the above-mentioned phase change microcapsules at the same time.

[0182] The above-mentioned phase change material layer 131 can be obtained by dispersing phase change microcapsules in a solvent to obtain a phase change microcapsule dispersion liquid, then immersing the thermal insulation substrate in the phase change microcapsule dispersion liquid to fill the phase change microcapsules in the pores of the thermal insulation substrate, and removing the solvent in the phase change microcapsule dispersion liquid.

[0183] In this way, the phase change microcapsules in the phase change material layer 131 play a role in absorbing heat. When the battery cell is in thermal runaway, the phase change material in the adjacent composite thermal insulation pad 10 is gasified and the packaging layer 132 is broken, that is, the composite thermal insulation pad 10 is disabled, and at this time the thermal insulation substrate in the phase change material layer 131 can continue to have a thermal insulation effect.

[0184] Further, the wall material comprises 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), for 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 large, the pressure resistance and heat insulation capacity of the wall material can be improved.

[0185] Further, the mass ratio of the polymer matrix to the core material is 1:(1.3-1.6), for 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. In this way, the pressure resistance of the phase change microcapsule can be further improved.

[0186] Further, the polymer matrix comprises 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 the phase change material such as paraffin, and can form a stable interface with the phase change material, thereby improving the thermal stability of the phase change microcapsule.

[0187] Further, the Dv50 particle size of the phase change microcapsule is 5-8 μm. The Dv50 particle size, i.e. the volume average particle size Dv50, represents the particle size corresponding to the cumulative volume distribution percentage of 50%, which can be tested by a method known in the art. For example, a laser particle size analyzer (such as Malvern Master Size 3000) is used for determination.

[0188] Further, the thermal conductivity of the wall material at 25°C is ≥0.32 W / mK. In this way, the wall material has good thermal conductivity, and can better conduct heat to the phase change material inside.

[0189] Further, the melting point of the wall material is >98°C. The wall material has a high melting point, and can keep the structure of the microcapsule stable within the phase change temperature range of the phase change material.

[0190] The material selection of the above-mentioned thermal insulation substrate and ceramic particles in the present 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 pad. The ceramic fiber pad has ceramic fibers as the core skeleton, which can not only well infiltrate the liquid phase change material, so that the phase change material fills in the pores of the core skeleton, but also has low thermal conductivity, good high temperature resistance (1280°C), instant heat shock resistance, flame retardant performance and mechanical performance, no powdering, and flexibility and resilience, and is compatible with the battery pack manufacturing process.

[0191] 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, and the like. Further, the ceramic particles have a Dv50 of 60-90 nm. As an example, the ceramic particles can have a Dv50 of any one of 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 83 nm, 85 nm, 90 nm, or between any two values. The above-mentioned specific particle size of the silicon dioxide particles is advantageous for doping and uniform dispersion in the base material.

[0192] The phase change microcapsules can be obtained by in-situ polymerization, in which the wall material is coated on the core material. In some examples, the preparation method of the 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, then stirring to form a Pickering emulsion, adding the raw materials required for preparing the polymer matrix of the wall material (such as a water-soluble polymer monomer or a pre-polymer aqueous solution) to the Pickering emulsion, and stirring at room temperature to polymerize to generate a cross-linked three-dimensional network structure of non-water-soluble condensation polymers (i.e., the polymer matrix) at the interface of the emulsion.

[0193] The polymer matrix of the above-mentioned material has better compatibility with the phase change material such as paraffin, and also facilitates uniform dispersion of the ceramic particles, thereby ensuring the stability of the phase change microcapsules.

[0194] Further, the battery 30 includes a plurality of battery cells 20, and the composite thermal insulation pad 10 is arranged between at least two adjacent battery cells 20. Generally, the battery includes a plurality of battery cells, and the system and capacity of the plurality of battery cells are the same.

[0195] Optionally, the composite thermal insulation pad 10 is arranged between any two adjacent battery cells 20. It can be understood that the composite thermal insulation pad 10 can also be arranged between the battery cell 20 and the inner wall of the shell of the battery 30.

[0196] It can be understood that the shape of the battery cell 20 includes, but is not limited to, a square shape and a cylindrical shape. The composite thermal insulation pad 10 can be arranged according to the shape of the battery cell 20.

[0197] In some embodiments, the battery cell 20 is square, and the composite thermal insulation pad 10 is arranged on the side surface (i.e., the large surface) of the battery cell 20 with a larger area, so as to increase the contact area and improve the thermal insulation performance.

[0198] It can be understood that after the plurality of battery cells 20 are connected to each other and arranged in a certain order, the plurality of battery cells 20 can be directly accommodated in the box to form a battery. Alternatively, the plurality of battery cells 20 can be combined to form a battery module, and then the plurality of battery modules are connected to each other to form a whole, and finally the whole of the battery module is accommodated in the box to form a battery.

[0199] FIG. 11 is a battery cell 20 of a square structure as an example. The battery cell 20 includes a case 21 having an opening, an electrode assembly 22 housed in the case 21, and a cover plate 23 sealingly provided to the opening. The electrode assembly 22 includes a positive electrode tab, a negative electrode tab, and a separator, which can be formed by a roll-pressing process or a stacking process.

[0200] Further, the electrode assembly 22 further includes an electrolyte, such as an electrolytic solution. The electrolytic solution is impregnated in the electrode assembly 22. The number of the electrode assemblies 22 included in the battery cell 20 can be one or more, which can be selected by a person skilled in the art according to a specific actual demand.

[0201] Further, one or both ends of the case 21 is provided with an opening.

[0202] Further, the case 21 is a cuboid case, and the opening direction of the case 21 is the height direction of the case 21. Further, both ends of the case 21 are provided with openings, and the two openings are oppositely arranged along the height direction of the case 21. Further, as a non-limiting example, the height of the case 21 is 80 mm to 210 mm; further, as a non-limiting example, the length of the case 21 is 90 mm to 240 mm; further, as a non-limiting example, the width of the case 21 is 20 mm to 80 mm.

[0203] Further, the battery cell 20 and the case 21 are cuboid cases, and the composite thermal insulation pad 10 is arranged on the larger area side of the battery cell 20, which is perpendicular to the above-mentioned width direction, i.e., the side formed by the two sides of the above-mentioned length direction and height direction.

[0204] Further, as a non-limiting example, the wall thickness of the case 21 is 0.5 mm to 0.8 mm.

[0205] Further, the case 21 is an aluminum alloy case; for example, a three-system aluminum alloy case or a five-system aluminum alloy case.

[0206] Further, the aluminum alloy of the three-system aluminum alloy case includes the following components with a 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%.

[0207] Further, the aluminum alloy of the five-system aluminum alloy case includes the following components with a 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 other element total components ≤ 0.15%.

[0208] Further, an electrolyte is also included in the electrode assembly 22. The electrolyte is impregnated in the electrode assembly 22. The number of electrode assemblies 22 contained in the battery cell 20 can be one or more, which can be selected by those skilled in the art according to specific actual needs.

[0209] The battery using the composite thermal insulation pad 10 described above works as follows: in the first stage, after thermal runaway occurs in a certain battery cell 20 in the battery 30, heat is transferred to the adjacent (e.g. adjacent) composite thermal insulation pad 10, and the phase change material layer 131 in the composite thermal insulation pad 10 absorbs the heat, thereby achieving the effect of blocking and slowing down the thermal runaway of the battery. In the second stage, the phase change material layer 131 absorbs heat until the phase change occurs, and a large amount of heat is absorbed. In the third stage, the encapsulation layer 132 and the phase change material layer 131 fail: the phase change material in the phase change material layer 131 is converted into a gaseous state and breaks the encapsulation layer 132, and the high-temperature gas is discharged. In the fourth stage, the thermal insulation substrate in the first thermal insulation layer 11 and the second thermal insulation layer 12 and the optional composite phase change layer 13 continues to play a role in thermal insulation.

[0210] Among them, the first stage and the second stage are the state before the composite thermal insulation pad 10 fails, and the third stage and the fourth stage are the state after the composite thermal insulation pad 10 fails.

[0211] Another embodiment of the present application also provides a power utilization device comprising the above-mentioned battery provided by the present application. The above-mentioned battery can be used as a power source of the power utilization device, or can be used as an energy storage unit of the power utilization device. The power utilization device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. Among them, the mobile device can be a mobile phone, a notebook computer, etc.; the electric vehicle can be 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 is not limited thereto.

[0212] As the power utilization device, a secondary battery, a battery module or a battery pack can be selected according to the use requirements thereof.

[0213] FIG. 12 is a power utilization device 40 as an example. The power utilization device 40 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the high power and high energy density requirements of the secondary battery for the power utilization device, a battery pack or a battery module can be used.

[0214] As another example of the device, it can be a mobile phone, a tablet computer, a notebook computer, etc. The device usually requires thinning, and a secondary battery can be used as a power source.

[0215] The following are specific embodiments.

[0216] Specifically, the following is the battery of Example 1. The battery comprises two battery monomers (i.e. battery cells) and a composite thermal insulation pad arranged between the two battery monomers; the two battery monomers are both five-system battery cells, i.e. NCM 523 The battery cells each have a capacity of 215 Ah. The composite thermal insulation pad comprises a first thermal insulation layer, a composite phase change layer and a second thermal insulation layer arranged in layers; the first thermal insulation layer and the second thermal insulation layer are both silica aerogel ceramic felt, and the composite phase change layer comprises a phase change material layer and an encapsulation layer arranged at the outer circumferential side of the phase change material layer, the encapsulation layer being an aluminum plastic film with a thickness of 0.2 mm, and the phase change material in the phase change material layer being CaCl2·6H2O.

[0217] The above battery was tested as follows: by triggering thermal runaway of the first battery cell (referred to as A battery cell), the thermal insulation performance of the composite thermal insulation pad on the second battery cell (referred to as B battery cell) was investigated. While keeping the overall thickness of the composite thermal insulation pad unchanged, the thickness of each layer of the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer was adjusted to investigate the influence of the internal film layer thickness of the composite thermal insulation pad on the thermal insulation performance of the composite thermal insulation pad. The composite thermal insulation pad has a size of 100 mm x 100 mm in a rectangular shape, and a total thickness of 6.3 mm, and the thickness of each film layer is shown in Table 2.

[0218] The test method is as follows: a heating table is heated. Temperature sensing wires are installed on the two large faces of the A battery cell and the two large faces of the B battery cell, the above battery is placed on the heating table, and an aluminum plate is pressed on the above battery, with a pressure of 3000 N. The temperature of the two large faces of the A battery cell and the two large faces of the B battery cell within 1000 s or 2000 s is measured to determine the thermal insulation effect of the thermal insulation pad. There are three sampling points for each face, one of which is the center point, and the other two are symmetrically distributed with the center point, with a spacing of 15 mm from the center point.

[0219] The thermal diffusion time (measured value) of batteries 1-4 obtained by the above test is shown in Table 2, wherein battery 1 is a pure thermal insulation pad without a composite phase change layer, and in battery 2, “2 mm + 2.3 mm + 2 mm” indicates that the thicknesses of the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer of the composite thermal insulation pad are 2 mm, 2.3 mm and 2 mm respectively, and the others are similar.

[0220] Table 2

[0221] The measured curves of the thermal insulation performance of batteries 2 and 3 are shown as curves 1a-1d in FIGS. 13 and 14, respectively.

[0222] Wherein, the A battery cell large face refers to the large face of the A battery cell directly contacting the heating table, and the other face opposite to it is the back face of the A battery cell. The B battery cell large face refers to the large face of the B battery cell directly contacting the composite thermal insulation pad, and the other face opposite to it is the back face of the B battery cell.

[0223] As can be seen from FIG. 13, within the test time 2000s, within the early stage 1150s, when the hot face temperature of the A cell large face reaches nearly 900°C, due to the heat insulation effect of the composite heat insulation pad, the temperature of the B cell large face is not more than 250°C, and the temperature of the B cell back face is not more than 100°C. Within the early stage 1150s, the temperature of the B cell large face is maintained at a temperature platform near 250°C from the maximum temperature of the A cell large face. The time length corresponding to the temperature platform (the temperature platform between the maximum temperature of the A cell large face and the inflection point of the temperature rise of the B cell large face) is the heat diffusion time in Table 2.

[0224] As can be seen from FIG. 14, within the test time 1000s, within the early stage 700s, when the hot face temperature of the A cell large face reaches nearly 900°C, due to the heat insulation effect of the composite heat insulation pad, the temperature of the B cell large face is not more than 350°C, and the temperature of the B cell back face is not more than 100°C. Within the early stage 700s, the temperature of the B cell large face is maintained at a temperature platform near 250°C from the maximum temperature of the A cell large face. The time length corresponding to the temperature platform (the temperature platform between the maximum temperature of the A cell large face and the inflection point of the temperature rise of the B cell large face) is the heat diffusion time in Table 2.

[0225] As can be seen from Table 2, under the condition that the thickness of the composite heat insulation pad is the same, the heat insulation performance of the composite heat insulation pad of battery 2-3 is better, and the heat insulation performance of the composite heat insulation pad of battery 2 is the best. For the ternary lithium battery cell of battery 2, the atomic proportion of nickel element in ternary elements is ≥50% and <70%, the thickness of the composite phase change layer is 2.3mm-3.3mm, and the thickness of the first heat insulation layer and the second heat insulation layer is 1.5mm-2.5mm. Further, the capacity of the battery cell is 215Ah, which belongs to the capacity of the battery cell ≥150Ah and <200Ah, and optionally, the thickness of the composite phase change layer is 2.3mm-3.3mm, and the thickness of the first heat insulation layer and the second heat insulation layer is independently 1.5mm-2mm.

[0226] In some embodiments, the film layer thickness of the composite heat insulation pad described above can be obtained by heat estimation model simulation screening. The heat diffusion time (simulation value) of batteries 1-4 obtained by heat estimation model simulation is shown in Table 2, and the simulation test curves of the heat insulation performance of batteries 2 and 3 are shown as curves 2a-1d in FIGS. 13 and 14, respectively. By comparing the measured value with the simulation value, it can be known that the error is within 15%. As shown in Table 2, the thickness of the better composite heat insulation pad is screened by the measured value and / or simulation value of the heat diffusion time. The thickness of the composite heat insulation pad in the above Table 2 of the present application is verified by measurement and heat estimation model simulation for different systems and capacities of the battery cell.

[0227] As shown in FIG. 15, a test method for a battery through a heat estimation model is shown, which can obtain test data, from which a simulated value of heat diffusion time can be obtained. Hereinafter, the method is applied to a computer device in FIG. 16 as an example. The computer device can be a terminal, and its internal structure diagram can be as shown in FIG. 16. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner. The wireless manner can be achieved through WIFI, mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by the processor to implement a test method for a battery. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad provided on the shell of the computer device, or an external keyboard, touchpad or mouse, etc. Those skilled in the art can understand that the structure shown in FIG. 16 is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. A specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0228] The test method for a battery through a heat estimation model includes the following steps:

[0229] S201, in response to an input instruction triggered by a user on a test interface, obtaining attribute parameters of a battery to be tested.

[0230] The input instruction is used to obtain attribute parameters of the battery to be tested input by the user on the test interface, and carries the attribute parameters of the battery to be tested. The attribute parameters are related parameters for calculating the heat diffusion performance of the battery. The test interface is the interface of a test application or simulation software, for example, the test interface of a test APP when the battery is tested using the test APP. The test application or simulation software can implement simulation model construction for the battery and perform testing based on the simulation model.

[0231] In the embodiments of the present application, a test application (such as a battery simulation APP) or simulation software is pre-installed on the computer device, and the test application or simulation software can be operated to simulate the test of the battery, thereby guiding the design of the battery. When the thermal runaway battery or the battery needs to be tested, the test application or simulation software for simulating the test of the battery can be started on the computer device, and the test interface corresponding to the test application or simulation software can be displayed on the display screen of the computer device. The user can input the attribute parameters of the battery to be tested on the test interface. After the user inputs the attribute parameters, the computer device can generate an input instruction carrying the attribute parameters, and the computer device can immediately respond to the input instruction triggered by the user on the test interface, analyze the input instruction, extract the attribute parameters of the battery to be tested from the input instruction, and obtain the attribute parameters of the battery to be tested. Optionally, after the user inputs the attribute parameters of the battery on the test interface, the computer device can also store the attribute parameters in the cache. When the computer device responds to the input instruction, the attribute parameters can be obtained from the cache according to the indication of the input instruction.

[0232] S202, in response to the test instruction triggered by the user on the test interface, inputting the attribute parameters to the heat estimation model for calculation to obtain the test data of the battery to be tested, and displaying the test data on the test interface.

[0233] The test instruction is used to start the test of the battery to be tested, that is, to test according to the attribute parameters and the heat estimation model, so as to test the simulated battery to be tested. The heat estimation model is used to calculate the thermal diffusion influence of the battery according to the attribute parameters. The test data includes the temperature change data of the large surface of each thermal runaway cell in the battery to be tested and the temperature change data of the bottom surface of the cell, such as the battery to be tested including thermal runaway cells A and thermal runaway cells B. The test data includes the temperature change data of the large surface of the thermal runaway cell A, the temperature change data of the bottom surface of the thermal runaway cell A, the temperature change data of the large surface of the thermal runaway cell B, and the temperature change data of the bottom surface of the thermal runaway cell B. The heat estimation model can be pre-constructed and stored in the database. The database can include various types of battery test models, which are used to provide calculation methods for battery performance testing. Optionally, the heat estimation model can be used to calculate the heat exchange between the thermal runaway cells in the battery to be tested and the air, and to calculate the internal thermal resistance of the thermal runaway cells, so as to calculate the thermal diffusion performance of the thermal runaway cells according to the two calculations.

[0234] Optionally, the heat estimation model can be determined by the following relationship (1):

[0235] Wherein, p represents the density of the cell, C prepresents the specific heat capacity of the battery cell, T represents the temperature of the battery cell, and τ represents the test time of the battery cell, represents the rate of change of temperature with time, and k represents the thermal conductivity, represents the self-generated heat of the battery cell. The density of the battery cell, the specific heat capacity of the battery cell, the self-generated heat of the battery cell, and the thermal conductivity all belong to the attribute parameters of the battery cell, and the computer device can calculate the density of the battery cell and the specific heat capacity of the battery cell based on some geometric parameters of the battery cell, such as the length of the battery cell, the width of the battery cell, the height of the battery cell, the thickness of the side shell of the battery cell, the thickness of the large surface shell of the battery cell, and the thickness of the ground shell of the battery cell. The density of the battery cell and the specific heat capacity of the battery cell can be calculated. Optionally, the density of the battery cell, the specific heat capacity of the battery cell, the thermal conductivity of the battery cell, and the self-generated heat of the battery cell can also be determined according to the specification of the battery cell.

[0236] In the embodiments of the present application, when the computer device obtains the attribute parameters of the battery to be tested based on the foregoing steps, the user can trigger the generation of a test instruction on the test interface by clicking a control, voice input, or text input, and the test instruction can optionally include the identifier of the heat estimation model. When the computer device responds to the test instruction triggered by the user on the test interface, the test instruction can be parsed to extract the identifier of the heat estimation model, and the heat estimation model can be further found in the database according to the identifier of the heat estimation model. The attribute parameters of the battery to be tested are input into the heat estimation model for calculation, and the temperature change data of each surface of the thermal runaway battery cell in the battery to be tested is calculated, i.e., the test data is obtained.

[0237] The test method described in the embodiments of the present application obtains the attribute parameters of the battery to be tested by responding to the input instruction triggered by the user on the test interface, and inputs the attribute parameters into the heat estimation model for calculation by responding to the test instruction triggered by the user on the test interface, to obtain the test data of the battery to be tested, and displays the test data on the test interface. The above-mentioned test method provides a simulation application that can test the battery to be tested, i.e., by inputting the corresponding test instruction on the test interface of the application, the thermal runaway condition or the thermal runaway heat dissipation condition of the battery to be tested can be tested according to the user's demand and by using the pre-set heat estimation model. Compared with the traditional method of actually testing the battery to be tested, the above-mentioned method is a user-operable simulation test method that does not rely on actual thermal runaway batteries for testing, can avoid additional costs caused by design trial and error to a certain extent, and can reduce the number of test experiments, thereby reducing the test cost of the battery to be tested and improving the test efficiency of the battery to a certain extent.

[0238] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the application embraces all such possible combinations.

[0239] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, some modifications 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 patent protection scope of the present application should be subject to the appended claims.

Claims

1. A battery comprising a battery cell and a composite thermal insulation pad disposed on at least one side of the battery cell, the composite thermal insulation pad comprising a first thermal insulation layer, a composite phase change layer, and a second thermal insulation layer stacked together, the composite phase change layer comprising a phase change material layer and an encapsulation layer disposed on the outer periphery of the phase change material layer, the composite phase change layer having a thickness of 1 mm to 4 mm, and the thicknesses of the first thermal insulation layer and the second thermal insulation layer each independently ranging from 1 mm to 3 mm.

2. The battery according to claim 1, wherein The battery satisfies at least one of the following conditions: (1) The thickness of the composite phase change layer is 1.5 mm to 3.5 mm; (2) The thickness of the first heat-insulating layer and the second heat-insulating layer are each independently 1 mm to 2.5 mm.

3. The battery according to claim 1, wherein The battery cell is a ternary lithium battery, the thickness of the composite phase change layer is 1.5 mm to 3.3 mm, and the thickness of the first heat insulation layer and the second heat insulation layer are each independently 1 mm to 2.5 mm.

4. The battery according to claim 3, wherein The atomic ratio of nickel element in the ternary positive electrode material in the battery cell is greater than 0 and less than 50% of the ternary elements, and the thickness of the first thermal insulation layer and the second thermal insulation layer are independently 1 mm to 2 mm.

5. The battery according to claim 4, wherein The battery meets one of the following conditions: (1) The capacity of the battery cell is less than 120 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (2) The capacity of the battery cell is ≥120Ah and <215Ah, the thickness of the composite phase change layer is 2.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5mm to 2mm; (3) The capacity of the battery cell is ≥215Ah and <260Ah, the thickness of the composite phase change layer is 3.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5mm to 2mm.

6. The battery according to claim 3, wherein The nickel element in the ternary positive electrode material in the battery cell accounts for ≥50% and <70% of the atoms of the ternary elements, the thickness of the composite phase change layer is 2.3mm to 3.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5mm to 2.5mm.

7. The battery according to claim 6, wherein The battery meets one of the following conditions: (1) The capacity of the battery cell is less than 150 Ah, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5 mm; (2) The capacity of the battery cell is ≥150Ah and <200Ah, and the thickness of the first thermal insulation layer and the second thermal insulation layer are independently 1.5mm to 2mm; (3) The capacity of the battery cell is ≥200 Ah and <260 Ah, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5 mm to 2.5 mm.

8. The battery according to claim 3, wherein The nickel element in the ternary positive electrode material of the battery cell accounts for ≥70% of the atomic proportion of the ternary elements.

9. The battery according to claim 8, wherein The battery meets one of the following conditions: (1) The capacity of the battery cell is less than 100 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (2) The capacity of the battery cell is ≥100 Ah and <120 Ah, the thickness of the composite phase change layer is 2.3 mm to 3.3 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (3) The capacity of the battery cell is ≥120 Ah, the thickness of the composite phase change layer is 2.3 mm to 3.3 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 2 mm to 2.5 mm.

10. The battery according to claim 1, wherein The battery cell is a lithium iron phosphate battery, the thickness of the composite phase change layer is 1.5 mm to 3.3 mm, and the thickness of the first heat insulation layer and the second heat insulation layer are each independently 1 mm to 2 mm.

11. The battery according to claim 10, wherein The battery meets one of the following conditions: (1) The capacity of the battery cell is less than 160 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (2) The capacity of the battery cell is ≥160Ah and <260Ah, the thickness of the composite phase change layer is 1.5mm to 2.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1mm to 1.5mm; (3) The capacity of the battery cell is ≥260Ah and <450Ah, the thickness of the composite phase change layer is 2.3mm to 3.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5mm to 2mm.

12. The battery according to claim 1, wherein The battery cell is a sodium ion battery, the thickness of the composite phase change layer is 1.5 mm to 2.3 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 2 mm.

13. The battery according to claim 12, wherein The battery meets one of the following conditions: (1) The capacity of the battery cell is less than 93 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (2) The capacity of the battery cell is ≥93 Ah and <117 Ah, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 1.5 mm; (3) The capacity of the battery cell is ≥117 Ah and <180 Ah, the thickness of the composite phase change layer is 1.5 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5 mm to 2 mm.

14. The battery according to any one of claims 1 to 13, wherein There are multiple battery cells, and the composite thermal insulation pad is arranged between at least two adjacent battery cells.

15. The battery according to claim 14, wherein The composite thermal insulation pad is arranged between the large surfaces of two adjacent battery cells.

16. The battery according to any one of claims 1 to 13, wherein The edges of the first heat-insulating layer and the second heat-insulating layer are connected to each other to form an assembly cavity, and the composite phase change layer is located in the assembly cavity.

17. The battery according to claim 16, wherein 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.

18. The battery according to any one of claims 1 to 13, wherein The composite thermal insulation pad also includes a first packaging frame and a second packaging frame. The first packaging frame is arranged on one side of the first thermal insulation layer, and the second packaging frame is arranged on one side of the second thermal insulation layer. The first packaging frame and the second packaging frame cooperate to fix the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer.

19. The battery according to claim 18, wherein The first packaging frame has a first limiting groove, the second packaging frame has a second limiting groove, and the first thermal insulation layer, the composite phase change layer and the second thermal insulation layer are limited in a limiting space formed by the first limiting groove and the second limiting groove.

20. The battery according to any one of claims 1 to 13, wherein The composite thermal insulation pad meets at least one of the following conditions: (1) The composite thermal insulation pad further includes a first adhesive layer and a second adhesive layer, wherein the first thermal insulation layer is connected to the encapsulation layer via the first adhesive layer, and the second thermal insulation layer is connected to the encapsulation layer via the second adhesive layer; (2) The composite thermal insulation pad further includes a release adhesive layer, the release adhesive layer including a third adhesive layer and a release film, the third adhesive layer being disposed on the outer surface of the first thermal insulation layer and the second thermal insulation layer, and the release film being disposed on the outer surface of the third adhesive layer; (3) The first thermal insulation layer and the second thermal insulation layer each independently comprise a ceramic material layer; (4) The encapsulation layer comprises an aluminum-plastic film or a polymer encapsulation film; (5) The thickness of the packaging layer is 0.1 mm to 0.3 mm.

21. The battery according to any one of claims 1 to 13, wherein The battery cell includes a housing; the housing satisfies at least one of the following characteristics: (1) The wall thickness of the shell is 0.5 mm to 0.8 mm; (2) The housing is a rectangular parallelepiped housing; (3) The shell is an aluminum alloy shell.

22. The battery according to any one of claims 1 to 13, wherein The battery cell includes a shell, which is a rectangular parallelepiped shell with an opening. The opening direction of the shell is the height direction of the shell. The height of the shell is 80mm to 210mm, the length of the shell is 90mm to 240mm, and the width of the shell is 20mm to 80mm.

23. An electrical device comprising the battery according to any one of claims 1 to 22.

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