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

Batteries and electrical devices

[0001] Related applications

[0002] This application claims priority to Chinese patent application number 2024202901603, filed with the China Patent Office on February 8, 2024, entitled “Battery and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery and an electrical device. Background Art

[0004] With the rapid development of new energy technologies, batteries are being used more and more widely in many fields, and people are placing higher and higher demands on battery performance, such as the energy density of batteries.

[0005] However, battery cells with higher energy density have high residual energy after thermal runaway. When one cell experiences thermal runaway, the heat from it continuously transfers to adjacent cells, causing heat diffusion throughout the battery and causing serious damage. Therefore, how to mitigate battery thermal runaway is an urgent problem that needs to be solved.

[0006] Summary of the Invention

[0007] Based on this, it is necessary to provide a battery and an electrical device to prevent the problem of 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 which are stacked together, 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 is 1 mm to 4 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 3 mm.

[0009] The above-mentioned battery with a composite thermal insulation pad, wherein the composite thermal insulation pad is provided with a first thermal insulation layer and a second thermal insulation layer at the same time, can play a good thermal insulation role; on the other hand, the composite phase change layer provided between the first thermal insulation layer and the second thermal insulation layer can absorb the heat transferred from the thermal insulation layers on both sides, thereby further improving the thermal insulation performance of the composite thermal insulation pad. The phase change material layer is provided 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 on the outside, and then before the packaging layer fails, the phase change material will not diffuse into the thermal insulation layer to form a heat conduction path, and thus will not change the structure of the thermal insulation layer and its thermal insulation performance; at the same time, the thickness 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 above-mentioned composite thermal insulation pad can obtain better thermal insulation performance at a lower thickness. The battery with the composite thermal insulation pad has a good effect of slowing down battery thermal runaway.

[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 the first heat-insulating layer and the second heat-insulating layer are each independently 1 mm to 2.5 mm.

[0013] In some embodiments, 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 thermal insulation layer and the second thermal insulation layer are each independently 1 mm to 2.5 mm.

[0014] In some embodiments, 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 each 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 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;

[0017] (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;

[0018] (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.

[0019] In some embodiments, 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 2.3 mm to 3.3 mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5 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 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;

[0022] (2) The capacity of the battery cell is ≥150Ah and <200Ah, 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;

[0023] (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 independently 1.5 mm to 2 mm.

[0024] In some embodiments, the nickel element in the ternary positive electrode material of the battery cell accounts for ≥70% of the atomic proportion of the ternary elements.

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

[0026] (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;

[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 thermal insulation layer and the second thermal insulation layer are 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 thermal insulation layer and the second thermal insulation layer are 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 1.5 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 2 mm.

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

[0031] (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;

[0032] (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;

[0033] (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.

[0034] In some embodiments, 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.

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

[0036] (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;

[0037] (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 independently 1 mm to 1.5 mm;

[0038] (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.

[0039] In some embodiments, there are multiple battery cells, and the composite thermal insulation pad is disposed between at least two adjacent battery cells.

[0040] In some embodiments, the composite thermal insulation pad is disposed between the large surfaces 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, an edge of at least one side surface of at least one of the first thermal insulation layer and the second thermal insulation layer forms a convex portion, and the convex portion encloses and forms at least a portion of the assembly cavity.

[0043] In some embodiments, 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, 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 the limiting space formed by the first limiting groove and the second limiting groove.

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

[0046] (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;

[0047] (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;

[0048] (3) The first thermal insulation layer and the second thermal insulation layer include ceramic material layers;

[0049] (4) The encapsulation layer comprises an aluminum-plastic film or a polymer encapsulation film;

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

[0051] In some embodiments, the battery cell includes a housing; the housing satisfies at least one of the following characteristics:

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

[0053] (2) The housing is a rectangular parallelepiped housing;

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

[0055] In some embodiments, the battery cell includes a shell, which is a rectangular 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 to 210mm, the length of the shell is 90mm to 240mm, and the width of the shell is 20mm to 80mm.

[0056] In a second aspect of the present application, an electrical device is provided, comprising any of the batteries described above.

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

[0058] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0059] FIG1 is a schematic structural diagram of a battery according to an embodiment of the present application;

[0060] FIG2 is a schematic diagram of the exploded structure of a battery according to one embodiment of the present application;

[0061] FIG3 is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to an embodiment of the present application;

[0062] FIG4 is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0063] FIG5 is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0064] FIG6 is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0065] FIG7 is a schematic diagram of the three-dimensional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0066] FIG8 is a schematic cross-sectional view of the composite thermal insulation pad shown in FIG7 taken along line AA;

[0067] FIG9 is an exploded cross-sectional view of the composite thermal insulation pad shown in FIG8 ;

[0068] FIG10 is a schematic diagram of the cross-sectional structure of a composite thermal insulation pad according to another embodiment of the present application;

[0069] FIG11 is a schematic structural diagram of a battery cell in a battery according to one embodiment;

[0070] FIG12 is a schematic diagram of an electrical device using a battery as a power source according to an embodiment of the present application;

[0071] FIG13 is a graph showing the measured thermal insulation performance of the battery 2 in Example 1 and a simulation test curve using a heat estimation model;

[0072] FIG14 is a graph showing the measured thermal insulation performance of the battery 3 in Example 1 and a simulation test curve using a heat estimation model;

[0073] FIG15 is a schematic flow chart of a testing method in one embodiment;

[0074] FIG16 is a diagram showing the internal structure of a computer device in one embodiment.

[0075] Explanation of the accompanying drawings: 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. Packaging layer; 1321. Packaging margin; 141. First packaging frame; 142. Second packaging 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. Electrical device. DETAILED DESCRIPTION

[0076] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0077] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0078] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0079] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0080] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0081] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0082] Currently, market developments indicate that batteries are becoming increasingly widely used. Batteries, particularly power batteries, are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in other fields. As the application of power batteries continues to expand, market demand is also growing.

[0083] A battery cell is the smallest unit that makes up a battery. A battery can contain one or more battery cells, and multiple battery cells can be connected in series, parallel, or in a hybrid connection. Hybrid connection refers to multiple battery cells being connected in both series and parallel.

[0084] After multiple battery cells are interconnected and arranged in a certain order, they can be directly placed in a box to form a battery. Alternatively, multiple battery cells can be first assembled into a battery module, and then multiple battery modules are interconnected to form a whole, and finally the entire battery module is placed in a box to form a battery.

[0085] To address the aforementioned battery thermal runaway issue and reduce the risk and degree of damage to the entire battery, this application provides a battery utilizing a composite thermal insulation mat, and optimizes the thickness of the composite thermal insulation mat's film layer to achieve a superior thermal insulation effect. Furthermore, this application optimizes the composite thermal insulation mat's film layer thickness based on the different battery cell systems and capacities, thereby achieving a superior thermal insulation effect.

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

[0087] Referring to Figure 3, the composite thermal insulation pad 10 includes a first thermal insulation layer 11, a composite phase change layer 13, and a second thermal insulation layer 12, which are stacked together. The composite phase change layer 13 includes a phase change material layer 131 and an encapsulation layer 132 disposed on the outer periphery of the phase change material layer 131. The composite phase change layer 13 has a thickness of 1 mm to 4 mm, and the thicknesses of the first thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1 mm to 3 mm.

[0088] The battery 30 using the composite thermal insulation pad 10 is provided with a first thermal insulation layer 11 and a second thermal insulation layer 12, which can provide excellent thermal insulation. Furthermore, the composite phase change layer 13 disposed between the first thermal insulation layer 11 and the second thermal insulation layer 12 can absorb heat transferred from the thermal insulation layers on both sides, thereby further improving the thermal insulation performance of the composite thermal insulation pad 10. The phase change material layer 131 is disposed within the encapsulation layer 132, thereby physically isolating the phase change material layer 131 within the composite phase change layer 13 from the external thermal insulation layer. Furthermore, before the encapsulation layer 132 fails, the phase change material will not diffuse into the thermal insulation layer to form a heat conduction path, thereby not changing the structure of the thermal insulation layer and its thermal insulation performance. This provides the composite thermal insulation pad 10 with excellent thermal insulation performance. Furthermore, by optimizing 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, the composite thermal insulation pad 10 can achieve better thermal insulation at a lower thickness. The battery using the composite thermal insulation pad 10 has a good effect of preventing thermal runaway of the battery.

[0089] The battery 30 using the above-mentioned composite thermal insulation pad 10, when the battery 30 is in normal working condition, mainly uses the first thermal insulation layer 11 and the second thermal insulation layer 12 located on the outside to play a thermal insulation role; when the battery 30 heats up abnormally, a large amount of heat is transferred 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 a phase change; when the phase change material layer 131 continues to absorb heat, the phase change material therein is converted into a gaseous state and breaks through the packaging layer 132, discharging the high-temperature gas and causing the packaging of the packaging layer 132 to fail. At this time, the first thermal insulation layer 11 and the second thermal insulation layer 12 continue to play a thermal insulation role.

[0090] In this application, unless otherwise specified, a "battery cell" refers to a basic unit that can achieve the mutual conversion of chemical energy and electrical energy. Further, generally speaking, it includes at least a positive electrode plate, a negative electrode plate, and an electrolyte. During the battery's charge and discharge process, active ions are embedded in and out of the positive and negative electrode plates. The electrolyte plays the role of conducting active ions between the positive and negative electrode plates.

[0091] As an example, the thickness of the composite phase change layer 13 can be 1mm, 1.5mm, 2mm, 2.3mm, 2.5mm, 3mm, or 3.5mm. It is 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 consisting of any two of the above-mentioned point values ​​as end values, similarly hereinafter, for example, 1.5mm to 3.5mm.

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

[0093] Furthermore, this application optimizes the film thickness of the composite thermal insulation pad 10 based on the different battery cell 20 systems, thereby achieving better thermal insulation. Battery cell 20 systems include ternary lithium batteries (referred to as ternary in Table 1), lithium iron phosphate batteries (LFP batteries), and sodium ion batteries (Na-ion batteries). Specific details are shown in Table 1 below.

[0094] Table 1

[0095] Please refer 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 insulation layer 11 and the second insulation layer 12 are each independently 1 mm to 2.5 mm.

[0096] Based on the different nickel content in the ternary positive electrode materials, the ternary lithium battery further optimizes the film thickness of the composite thermal insulation pad 10 to obtain 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 ratio of nickel element to ternary elements. 811 Taking the ternary positive electrode material as an example, its nickel content refers to the atomic ratio of nickel element in the ternary elements of nickel, cobalt and manganese, which is 80%.

[0097] The ternary cathode material in this application contains nickel, 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) may 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) may include LiNi 0.8 Co 0.15 Al 0.05 O2.

[0098] In some embodiments, the nickel element in the ternary positive electrode material in the battery cell 20 accounts for an atomic ratio of ternary elements greater than 0 and less than 50%, and the ternary positive electrode 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 thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1 mm to 2 mm.

[0099] Furthermore, under the same battery cell 20 system, the present application optimizes the film thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cells 20, thereby achieving a better thermal insulation effect. Specifically, the battery cell 20 is a ternary lithium battery, and the nickel element in the ternary positive electrode material in the battery cell 20 accounts for an atomic ratio greater than 0 and less than 50% of the ternary elements. Based on the different capacities of the battery cells 20, there are three solutions as follows (1) to (3).

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

[0101] (2) The capacity of the battery cell 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 thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1.5 mm to 2 mm.

[0102] (3) The capacity of the battery cell 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 thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1.5 mm to 2 mm.

[0103] In this way, as the capacity of the battery cell 20 increases, the thickness of the composite phase change layer 13 increases accordingly, which can significantly improve the thermal insulation effect of the composite thermal insulation pad 10; 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 at the same total thickness, which is beneficial to reducing the volume occupied by the battery.

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

[0105] Furthermore, under the same battery cell 20 system, the present application optimizes the film thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cells 20, thereby achieving a better thermal insulation effect. Specifically, the battery cell 20 is a ternary lithium battery, and the nickel element of the ternary positive electrode material in the battery cell 20 accounts for ≥50% and <70% of the atomic ratio of the ternary elements. Based on the different capacities of the battery cells 20, there are three solutions as follows (1) to (3).

[0106] (1) The capacity of the battery cell 20 is less than 150 Ah, the thickness of the composite phase change layer 13 is 2.3 mm to 3.3 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1.5 mm.

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

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

[0109] Furthermore, while the battery cells 20 system is identical, this application optimizes the film thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cells 20, thereby achieving a better thermal insulation effect. The nickel element in the ternary positive electrode material in the battery cells 20 has an atomic fraction of ≥70% of the ternary elements. This ternary positive electrode material is generally considered a high-nickel ternary system, with a nickel fraction of <100%. The composite phase change layer 13 has a thickness of 1.5 mm to 3.3 mm, and the thicknesses of the first thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1 mm to 2.5 mm.

[0110] Furthermore, under the same battery cell 20 system, the present application optimizes the film thickness of the composite thermal insulation pad based on the different capacities of the battery cells 20, thereby achieving a better thermal insulation effect. Specifically, the battery cell 20 is a ternary lithium battery, and the nickel element of the ternary positive electrode material in the battery cell 20 accounts for ≥70% of the atomic ratio of the ternary elements. Based on the different capacities of the battery cells 20, there are three solutions as follows (1) to (3).

[0111] (1) The capacity of the battery cell 20 is less than 100 Ah, the thickness of the composite phase change layer 13 is 1.5 mm, and the thicknesses of the first thermal insulation layer 11 and the second thermal insulation layer 12 are independently 1 mm to 1.5 mm;

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

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

[0114] 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 at the same total thickness, which is conducive to reducing the volume occupied by the battery. In (2) and (3), as the capacity of the battery cell 20 continues to increase, continuing to increase the thickness of the composite phase change layer 13 is too costly and the effect is not obvious. In this case, the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 can be further increased to further improve 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 1.5 mm to 3.3 mm, and the thickness of the first thermal insulation layer 11 and the second thermal insulation layer 12 are each independently 1 mm to 2 mm.

[0116] Furthermore, under the same battery cell 20 system, the present application optimizes the film thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cells 20, thereby achieving 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 cells 20, there are three solutions as follows (1) to (3).

[0117] (1) The capacity of the battery cell 20 is less than 160 Ah, the thickness of the composite phase change layer 13 is 1.5 mm, and the thicknesses of the first thermal insulation layer 11 and the second thermal insulation layer 12 are independently 1 mm to 1.5 mm;

[0118] (2) The capacity of the battery cell 20 is ≥160 Ah and <260 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 are each independently 1 mm to 1.5 mm;

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

[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 present application is greatly improved at the same total thickness, which is conducive to reducing the volume occupied by the battery. 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 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.

[0121] In some embodiments, the battery cell 20 is a sodium ion battery, 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 are each independently 1 mm to 2 mm.

[0122] Sodium-ion batteries contain sodium-ion active materials. As non-limiting examples, the sodium-ion active materials may include one or more of the following: sodium transition metal oxides, polyanionic compounds, and Prussian blue compounds. However, the present application is not limited to these materials; other conventionally known materials that can be used as positive electrode active materials for sodium-ion batteries may also be used.

[0123] Furthermore, under the same battery cell 20 system, the present application optimizes the film thickness of the composite thermal insulation pad 10 based on the different capacities of the battery cells 20, thereby achieving a better thermal insulation effect. Specifically, the battery cells 20 are sodium ion batteries, and based on the different capacities of the battery cells 20, there are three solutions as follows (1) to (3).

[0124] (1) The capacity of the battery cell 20 is less than 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 are each 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 are each 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 are each 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 at the same total thickness, which is conducive to reducing the volume occupied by the battery. 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] Traditional technology is limited by its structure, and phase change materials can only use solid phase change materials. However, solid phase change materials have limited heat absorption capacity. The above-mentioned composite thermal insulation pad 10, because its phase change material layer 131 is arranged in the packaging cavity of the packaging layer 132, the phase change material layer 131 is physically isolated from the external thermal insulation layer. Therefore, the phase change material of its 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 crystal water and salt, phase change molten salt, paraffin, silicone oil, silica-alumina sol, fatty acids, alcohols and other substances that can undergo phase change and absorb heat, and its scope of application is wider.

[0129] Furthermore, because the phase-change material in phase-change material layer 131 undergoes a phase change—for example, a solid phase-change material at room temperature transforms into a liquid state after absorbing heat—encapsulation layer 132 also serves as a heat-insulating layer that isolates the liquid phase-change material from the external heat source. Furthermore, some manufacturing processes inevitably introduce moisture into the phase-change material. By placing phase-change material layer 131 within the encapsulation cavity of encapsulation layer 132, this structure prevents moisture from escaping and adversely affecting the battery.

[0130] Referring to Figure 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 is connected to the encapsulation layer 132 via the first adhesive layer 151, and the second thermal insulation layer 12 is connected to the encapsulation layer 132 via the second adhesive layer 152. In this manner, the adhesive layers securely connect 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 in the thickness direction.

[0131] Furthermore, the material of the first adhesive layer 151 and the second adhesive layer 152 is independently a silicone adhesive layer, and the thickness is independently 0.04 to 0.06 mm. The silicone adhesive layer is resistant to high temperatures and has high structural strength. The peeling force of the prepared composite thermal insulation pad is greater than 10N / cm. The peeling force can be measured by pulling the two sides of the composite thermal insulation pad with a tensile gauge, and applying a force perpendicular to the composite thermal insulation pad at 90° to the two sides of the composite thermal insulation pad outward. The tensile gauge will display the magnitude of the pulling force when the composite thermal insulation pad is peeled off, and the peeling force can be obtained based on the magnitude of the pulling 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 disposed on the outer surface of the first thermal insulation layer 11 and the second thermal insulation layer 12, and the release film is disposed on the outer surface of the third adhesive layer. In this way, when the composite thermal insulation pad 10 needs to be fixed to a target position, such as a target battery cell, the release film on the surface of the release adhesive layer on the composite thermal insulation pad 10 is removed, and the composite thermal insulation pad 10 is simply and conveniently fixed to the target position by bonding with the third adhesive layer, thereby fixing the composite thermal insulation pad 10.

[0133] As an example, the aforementioned release adhesive layer is provided on the outer surfaces of the first insulation layer 11 and the second insulation layer 12 of the composite thermal insulation mat 10. During use, the composite thermal insulation mat 10 can be bonded and fixed to two objects, for example, two adjacent battery cells, using the release adhesive layers on both sides, so that the composite thermal insulation mat 10 is positioned between the two adjacent battery cells.

[0134] As shown in FIG. 4 , the first thermal insulation layer 11 and the second thermal insulation layer 12 are physically separated 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 of the first thermal insulation layer 11 and the second thermal insulation layer 12 are respectively adapted to the length and width of the composite phase change layer 13. In other embodiments, at least one of the length and width of the first thermal insulation layer 11 and the second thermal insulation layer 12 is greater than the corresponding length or width of the composite phase change layer 13.

[0136] Referring to Figure 5 , in some embodiments, the edges of the first and second thermal insulation layers 11, 12 are connected to form an assembly cavity, within which the composite phase change layer 13 is located. This structural arrangement allows the composite phase change layer 13 to be positioned within the first and second thermal insulation layers 11, 12, reducing the risk of the composite phase change layer 13 falling off.

[0137] Furthermore, the edge of at least one side surface of at least one of the first thermal insulation layer 11 and the second thermal insulation layer 12 forms a convex portion, and the convex portion encloses at least part of the assembly cavity. As an example, the edge of at least one side surface of both the first thermal insulation layer 11 and the second thermal insulation layer 12 forms a convex portion, and the convex portions of the two are arranged relative to each other and enclose the assembly cavity. In the specific example shown in Figure 5, the edges of the four sides of the surface of one side of the first thermal insulation layer 11 and the second thermal insulation layer 12 form a convex portion, and the convex portions of the first thermal insulation layer 11 and the second thermal insulation layer 12 are arranged relative to each other and enclose the assembly cavity.

[0138] Typically, both sides of phase-change material layer 131 are encapsulated with an encapsulation film, leaving an encapsulation margin on its sides, such as encapsulation margin 1321 shown in FIG. 9 . That is, encapsulation layer 132 has an encapsulation margin. When composite phase-change layer 13 is disposed within first and second insulation layers 11, 12, the encapsulation margin is folded and positioned within the assembly cavity.

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

[0140] Referring to Figure 6, in some embodiments, the composite thermal insulation pad 10 further includes a third thermal insulation layer 16, and a composite phase change layer 13 is also provided between the second thermal insulation layer 12 and the third thermal insulation layer 16. Furthermore, the composite thermal insulation pad 10 may further include more thermal insulation layers, and the composite phase change layer 13 may also be provided between the adjacent thermal insulation layers.

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

[0142] Please refer to Figures 7 and 8. In some embodiments, the composite thermal insulation pad 10 also includes a first packaging frame 141 and a second packaging frame 142. The first packaging frame 141 is arranged on one side of the first thermal insulation layer 11, and the second packaging frame 142 is arranged on one side of the second thermal insulation layer 12. The first packaging frame 141 and the second packaging 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] Furthermore, the first packaging frame 141 and the second packaging frame 142 are each independently a rubber frame or a silicone frame. In other words, the first packaging frame 141 and the second packaging frame 142 are each independently made of rubber or silicone. Furthermore, the first packaging frame 141 and the second packaging frame 142 are both shaped like a truncated frame, such as a silicone truncated frame.

[0144] In the example shown in Figures 8 and 9, the first packaging frame 141 has a first limiting groove (not shown), and the second packaging frame 142 has a second limiting groove (not shown). The first thermal insulation layer 11, the composite phase change layer 13 and the second thermal insulation layer 12 are limited in the limiting space formed by the first limiting groove and the second limiting groove. The first limiting groove and the second limiting groove can limit the 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. Among them, the radial direction of the composite thermal insulation pad 10 refers to the direction from the center of the composite thermal insulation pad 10 to the edge of the composite thermal insulation pad 10. Furthermore, at this time, the packaging margin 1321 of the packaging layer 132 can be located between the first packaging frame 141 and the second packaging frame 142. As shown in Figure 9, the packaging margin 1321 is pressed in the middle by the first packaging frame 141 and the second packaging frame 142.

[0145] It can be understood that when the above-mentioned first packaging frame 141 and second packaging frame 142 and the above-mentioned first thermal insulation layer 11 and second thermal insulation layer 12 that can form an assembly cavity are provided at the same time, the packaging margin portion 1321 of the packaging layer 132 can pass through between the convex portions of the first thermal insulation layer 11 and the second thermal insulation layer 12 and be located between the first packaging frame 141 and the second packaging frame 142, or the packaging margin portion 1321 of the packaging layer 132 can also be folded and located in the assembly cavity.

[0146] Referring to Figure 10 , in other embodiments, the outer surface of the first thermal insulation layer 11 is flush with the outer surface of the first packaging frame 141, and / or the outer surface of the second thermal insulation layer 12 is flush with the outer surface of the second packaging frame 142. This can minimize the thickness of the composite thermal insulation pad 10 and reduce the space it occupies while providing better thermal insulation performance.

[0147] As an example, based on the aforementioned first adhesive layer 151 and second adhesive layer 152, the aforementioned first packaging frame 141 and second packaging frame 142 can be further used to secure the first thermal insulation layer 11, the composite phase change layer 13, and the second thermal insulation layer 12 around their perimeters, thereby improving the structural stability of the composite thermal insulation pad 10. Furthermore, in this case, there is no need for the packaging frame to secure the thickness direction, so that the outer surface of the first thermal insulation layer 11 can be flush with the outer surface of the first packaging frame 141, and the outer surface of the second thermal 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 thermal insulation layer 11, the composite phase change layer 13, the second thermal insulation layer 12, and the third thermal insulation layer 16 can be connected by the above-mentioned adhesive layer, or by the above-mentioned packaging frame, or by both the above-mentioned adhesive layer and the packaging frame, or by neither, for example, the first thermal insulation layer 11 can be directly formed on the packaging layer 132 of the composite phase change layer 13.

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

[0150] Furthermore, when any of the aforementioned thermal insulation layers includes both a thermal insulation felt and a thermal insulation coating, the thermal insulation coating may be optionally disposed on a side closer to the composite phase change layer 13. Specifically, the thermal insulation coating is disposed on the surface of the encapsulation layer 132 of the composite phase change layer 13, and the thermal insulation felt is disposed on a side further away from the composite phase change layer 13. In other words, the thermal insulation coating is formed directly on the surface of the encapsulation layer 132 and is located between the encapsulation layer 132 and the thermal insulation felt.

[0151] For example, in the examples of Figures 3, 4 and 6, the first thermal insulation layer 11 and the second thermal insulation layer 12 are thermal insulation felt, and the third thermal insulation layer 16 is also thermal insulation felt. In other examples, the first thermal insulation layer 11 and the second thermal insulation layer 12 may also be thermal insulation coatings. In comparison, the thickness of the thermal insulation coating is thinner, and the overall thickness of the composite thermal insulation pad obtained is thinner, and the required space is relatively smaller. The thermal insulation layer of the composite thermal insulation pad 10 can optionally adopt a thermal insulation coating, or a composite of a thermal insulation coating and ceramic felt, which can take into account both a smaller occupied space and better thermal insulation performance.

[0152] For example, in the example shown in FIG5 , the first insulation layer 11 and the second insulation layer 12 are insulation felts, and the assembly cavity thereon can be integrally formed when the insulation felt is formed, or can be formed by grooving after the insulation felt is formed.

[0153] It is understood that the thermal insulation felt can be connected to the composite phase change layer 13 via the aforementioned adhesive layer or encapsulation frame. The thermal insulation coating can be formed directly on the encapsulation layer 132 in the composite phase change layer 13. As an example, the thermal insulation coating can be formed by coating the encapsulation layer 132 of the composite phase change layer 13 with a slurry and then drying it to form a coating.

[0154] Furthermore, the thermal insulation felt may be a ceramic thermal insulation felt; further, the thermal insulation coating may 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 meet the following conditions: thermal conductivity at 25°C ≤ 0.020 W / m·K, thermal conductivity at 200°C ≤ 0.027 W / m·K, thermal conductivity at 300°C ≤ 0.035 W / m·K, and thermal conductivity at 500°C ≤ 0.080 W / m·K.

[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 independently 0.2 g / cm 3 ~0.22g / cm 3 .

[0157] In this article, the following method can be used to test the thickness of composite insulation pads. The equipment used is a Mitutoyo 547-301 thickness gauge with an accuracy of ≤0.01mm. During testing, the composite insulation pad and the Mitutoyo 547-301 thickness gauge must be parallel to the ground. The test points are located at four corners and the center area, with the average of these five points being used as the test value.

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

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

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

[0161] The material of the "ceramic material layer" in this application includes, but is not limited to, at least one of ceramic oxides, ceramic nitrides, and ceramic carbides. The ceramic oxides include, but are not limited to, at least one of silicon oxide and aluminum oxide, the ceramic nitrides include, but are not limited to, silicon nitride, and the ceramic carbides include, but are not limited to, silicon carbide.

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

[0163] Furthermore, the ceramic insulation felt may be a silica aerogel ceramic felt. As an example, the silica aerogel ceramic felt may be prepared by inorganic fiber reinforcement technology to prepare aerogel materials, through impregnation sol, gel, solvent replacement and supercritical drying processes.

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

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

[0166] Furthermore, the packaging layer 132 includes a polypropylene layer, an aluminum layer, and a nylon layer stacked from the inside to the outside.

[0167] Furthermore, the polymer packaging film may be a PET film (polyethylene terephthalate film) or a PI film (polyimide film).

[0168] In some embodiments, a weak portion is provided in the area of ​​the packaging layer 132 that forms the packaging cavity. Because the weak portion is located in 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 a phase change, causing the packaging layer 132 to bulge. This allows the packaging layer 132 to rupture promptly at the weak portion in the event of thermal runaway, further reducing the damage to the battery as a whole.

[0169] It can be understood that the weak portion on the encapsulation layer 132 is an area on the encapsulation layer 132 where the strength is relatively weak.

[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 includes a heat-insulating substrate in addition to the phase change material, and at least a portion of the phase change material is filled in the pores of the heat-insulating substrate. In other words, the pores of the heat-insulating substrate are filled with the phase change material.

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

[0179] Furthermore, in some examples, at least a portion of the phase change material is directly filled into the pores of the thermal insulation substrate. In other examples, the phase change material can also be filled into the pores of the thermal insulation substrate in the form of phase change microcapsules. It is understood that the same thermal insulation substrate can also include two phase change material states: one in which the phase change material is directly filled into the pores of the thermal insulation substrate, and the other in which the phase change material is filled into the pores of the thermal insulation substrate in the form of phase change microcapsules.

[0180] It is understood that the phase change material layer 131 can be obtained by soaking a porous thermal insulation substrate such as ceramic fiber felt in a liquid phase change material, for example, by soaking it in a molten phase change material and then cooling it, or by soaking it in a phase change material solution and then drying or heat-insulating it. In addition to absorbing heat, the phase change material layer 131 can also provide thermal insulation. When the phase change material vaporizes and breaks through the encapsulation layer 132, that is, the composite thermal insulation pad 10 fails, the thermal insulation substrate in the phase change material layer 131 can continue to provide thermal insulation. In other words, the phase change material directly fills the pores of the thermal insulation substrate.

[0181] In other embodiments, at least a portion 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 microcapsules include a core material and a wall material, wherein the wall material is wrapped around the outer surface of the core material, and the core material includes the phase change material. It is understood that in some examples, the pores of the thermal insulation substrate can also be directly filled with the phase change material and the aforementioned 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, then immersing a thermal insulation substrate in the phase change microcapsule dispersion to fill the phase change microcapsules in the pores of the thermal insulation substrate, and removing the solvent in the phase change microcapsule dispersion.

[0183] In this way, the phase change microcapsules in the phase change material layer 131 absorb heat. When the battery cell thermally runs away, the phase change material in the adjacent composite thermal insulation pad 10 vaporizes and breaks the packaging layer 132, that is, the composite thermal insulation pad 10 fails. At this time, the thermal insulation substrate in the phase change material layer 131 can continue to play a thermal insulation role.

[0184] Furthermore, the wall material includes a polymer matrix and ceramic particles filled in the polymer matrix. Furthermore, the mass ratio of the polymer matrix to the ceramic particles is 3:(7-11). As an example, the mass ratio of the polymer matrix to the ceramic particles can be 3:7, 3:8, 3:9, 3:10, or 3:11. By controlling the mass content of ceramic particles in the wall material to be relatively high, the pressure resistance and thermal insulation capabilities of the wall material can be improved.

[0185] Furthermore, the mass ratio of the polymer matrix to the core material is 1:(1.3-1.6). As an example, the mass ratio of the polymer matrix to the core material can be 1:1.3, 1:1.4, 1:1.5, or 1:1.6. This can further improve the pressure resistance of the phase change microcapsules.

[0186] Furthermore, the polymer matrix includes, but is not limited to, any one of phenolic resin, polyacrylonitrile resin, melamine formaldehyde resin, etc. The polymer matrix not only has good insulation properties, but also has good compatibility with phase change materials such as paraffin wax, and can form a stable interface with the phase change material, thereby improving the thermal stability of the phase change microcapsules.

[0187] Furthermore, the phase-change microcapsules have a Dv50 particle size of 5 μm to 8 μm. The Dv50 particle size, also known as the volume average particle size (Dv50), represents the particle size corresponding to 50% of the cumulative volume distribution of the particles. This can be measured using methods known in the art, for example, using a laser particle size analyzer (e.g., Malvern Master Size 3000).

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

[0189] Furthermore, the melting point of the wall material is greater than 98° C. The high melting point of the wall material can maintain the structural stability of the microcapsule 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 this application is the same as the selection range of the above-mentioned ceramic material layer. In some examples, the above-mentioned thermal insulation substrate is a ceramic fiber mat. The ceramic fiber mat has ceramic fiber as the core skeleton, which can not only well infiltrate the liquid phase change material so that the phase change material is filled in the pores of its core skeleton, but also has low thermal conductivity, good high temperature resistance (1280°C), resistance to instantaneous thermal shock, flame retardant properties and mechanical properties, no powdering, and is flexible and resilient, and is compatible with the battery pack manufacturing process.

[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, and silicon dioxide particles. Furthermore, the ceramic particles have a Dv50 of 60 nm to 90 nm. For example, the Dv50 of the ceramic particles can be any value among 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 83 nm, 85 nm, and 90 nm, or between any two values. Silicon dioxide particles of this specific particle size facilitate doping and uniform dispersion in the substrate.

[0192] Phase-change microcapsules can be obtained by in-situ polymerization, where the wall material is coated with the core material. In some examples, the preparation method of phase-change microcapsules includes the following steps: dispersing ceramic particles in water to form an aqueous phase; heating the phase-change material to a molten state to form an oil phase; mixing the aqueous and oil phases and stirring to form a Pickering emulsion; adding the raw materials required to prepare the polymer matrix of the wall material (such as a water-soluble polymer monomer or prepolymer aqueous solution) to the Pickering emulsion; and stirring and polymerizing at room temperature to form a water-insoluble condensation polymer (i.e., the polymer matrix) with a cross-linked three-dimensional network structure at the emulsion interface.

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

[0194] Furthermore, the battery 30 includes multiple battery cells 20, and the composite thermal insulation pad 10 is disposed between at least two adjacent battery cells 20. Generally, a battery includes multiple battery cells, and the multiple battery cells have the same system and capacity.

[0195] Optionally, a composite thermal insulation pad 10 is provided between any two adjacent battery cells 20. It is understood that the composite thermal insulation pad 10 may also be provided between the battery cells 20 and the inner wall of the battery 30 housing.

[0196] It is understood that the shape of the battery cell 20 includes but is not limited to square and cylindrical. The composite thermal insulation pad 10 can be arranged in a manner consistent with 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 disposed on the side surface (ie, the large surface) of the battery cell 20 to increase its contact area and improve the thermal insulation performance.

[0198] It is understood that after multiple battery cells 20 are interconnected and arranged in a certain order, they can be directly housed in a housing to form a battery. Alternatively, multiple battery cells 20 can be first assembled into a battery module, and then the multiple battery modules are interconnected to form a whole, and finally the entire battery module is housed in a housing to form a battery.

[0199] Figure 11 shows a square-shaped battery cell 20 as an example. The battery cell 20 includes a housing 21, a cover plate 23, and an electrode assembly 22. The housing 21 has an opening, and the electrode assembly 22 is housed within the housing 21. The cover plate 23 is sealed in the opening. The electrode assembly 22 includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet, negative electrode sheet, and separator can be formed by a winding process or a lamination process.

[0200] Furthermore, the electrode assembly 22 also includes an electrolyte, such as an electrolyte solution. The electrolyte solution is immersed in the electrode assembly 22. The number of electrode assemblies 22 included in the battery cell 20 can be one or more, and those skilled in the art can select the number based on specific practical needs.

[0201] Furthermore, one or both ends of the housing 21 are provided with an opening.

[0202] Furthermore, the housing 21 is a rectangular parallelepiped housing, and the opening of the housing 21 is oriented along the height of the housing 21. Furthermore, the housing 21 has openings at both ends, and the two openings are arranged opposite each other along the height of the housing 21. Further, as a non-limiting example, the height of the housing 21 is 80 mm to 210 mm; further, as a non-limiting example, the length of the housing 21 is 90 mm to 240 mm; further, as a non-limiting example, the width of the housing 21 is 20 mm to 80 mm.

[0203] Furthermore, the battery cell 20 and the shell 21 are rectangular shells, and the composite insulation pad 10 is arranged on the side of the battery cell 20 with a larger area. The side of the larger area is perpendicular to the above-mentioned width direction, that is, the side formed by the two sides of the above-mentioned length direction and height direction.

[0204] As a further non-limiting example, the wall thickness of the housing 21 is 0.5 mm to 0.8 mm.

[0205] Furthermore, the housing 21 is an aluminum alloy housing; for example, a third-series aluminum alloy housing or a fifth-series aluminum alloy housing.

[0206] Furthermore, the aluminum alloy of the three-series aluminum alloy shell includes the following components in percentage by mass: 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] Furthermore, the aluminum alloy of the fifth series aluminum alloy shell includes the following components in percentage by mass: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and the total components of other elements ≤ 0.15%.

[0208] Furthermore, the electrode assembly 22 also includes an electrolyte. The electrolyte is soaked in the electrode assembly 22. The number of electrode assemblies 22 included in the battery cell 20 can be one or more, and those skilled in the art can select according to specific actual needs.

[0209] The working principle of the battery using the above-mentioned composite thermal insulation pad 10 is as follows: In the first stage, after a battery cell 20 in the battery 30 undergoes thermal runaway, the heat is transferred to the adjacent (for example, adjacent) composite thermal insulation pad 10, and the phase change material layer 131 in the composite thermal insulation pad 10 absorbs heat, thereby preventing the battery from thermal runaway. In the second stage, the phase change material layer 131 absorbs heat until a phase change occurs, absorbing a large amount of heat. 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 gas and breaks through the encapsulation layer 132, discharging the high-temperature gas. In the fourth stage, the first thermal insulation layer 11 and the second thermal insulation layer 12 and the optional thermal insulation substrate in the composite phase change layer 13 continue to play a role in thermal insulation.

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

[0211] Another embodiment of the present application further provides an electrical device, comprising the battery provided herein. The battery can be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices, electric vehicles, electric trains, ships, satellites, energy storage systems, and the like. Examples of mobile devices include, but are not limited to, mobile phones and laptop computers; examples of electric vehicles include, but are not limited to, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, and electric trucks.

[0212] As an electrical device, a secondary battery, a battery module or a battery pack can be selected according to its usage requirements.

[0213] Figure 12 shows an example of an electric device 40. The electric device 40 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the electric device's requirements for high power and high energy density of secondary batteries, a battery pack or battery module can be used.

[0214] Another example device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is generally required to be lightweight and thin, and may use a secondary battery as a power source.

[0215] The following are specific examples.

[0216] Specifically, the following is a battery of Example 1. The battery includes two battery cells (ie, battery cores) and a composite thermal insulation pad disposed between the two battery cells; the two battery cells are both five-series battery cells, namely NCM 523 The battery cells all have a capacity of 215Ah. The composite thermal insulation pad includes a stacked first thermal insulation layer, a composite phase change layer, and a second thermal insulation layer. Both the first and second thermal insulation layers are made of silica aerogel ceramic felt. The composite phase change layer includes a phase change material layer and an encapsulation layer disposed on the outer periphery of the phase change material layer. The encapsulation layer is a 0.2mm thick aluminum-plastic film, and the phase change material in the phase change material layer is CaCl2·6H2O.

[0217] The battery was tested as follows: by triggering thermal runaway in the first cell (referred to as cell A), the thermal insulation performance of the composite thermal pad on the second cell (referred to as cell B) was examined. While maintaining the overall thickness of the composite thermal pad, the thickness of the first thermal insulation layer, the composite phase change layer, and the second thermal insulation layer were adjusted to examine the effect of the internal film thickness on the thermal insulation performance of the composite thermal pad. The composite thermal pad was a 100mm x 100mm rectangular with a total thickness of 6.3mm. The thickness of each film layer is shown in Table 2.

[0218] The test method is as follows: Heat the heating table. Install temperature sensors on the two large surfaces of battery cell A and battery cell B, place the batteries on the heating table, and press an aluminum plate onto the batteries with a pressure of 3000N. Measure the temperature of the two large surfaces of battery cell A and battery cell B within 1000s or 2000s to determine the insulation effect of the thermal pad. Each surface has three temperature sampling points: one at the center, and the other two are symmetrically distributed around the center, with a spacing of 15mm between them.

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

[0220] Table 2

[0221] The measured curves of the thermal insulation performance of Battery 2 and Battery 3 are shown as curves 1a to 1d in FIG13 and FIG14 , respectively.

[0222] The "large surface" of cell A refers to the large surface that is in direct contact with the heating platform, and the other side opposite to it is the back of cell A. The "large surface" of cell B refers to the large surface that is in direct contact with the composite insulation pad, and the other side opposite to it is the back of cell B.

[0223] As shown in Figure 13, within the 2000s test time, when the hot surface temperature of cell A's large surface reached nearly 900°C within the first 1150s, the temperature of cell B's large surface did not exceed 250°C, and the temperature on the back of cell B did not exceed 100°C due to the insulating effect of the composite thermal pad. During the first 1150s, the temperature of cell B's large surface remained essentially at a temperature platform near 250°C, extending from the maximum temperature of cell A's large surface. The duration of this temperature platform (the temperature platform between the maximum temperature of cell A's large surface and the inflection point where the temperature of cell B's large surface rises) is the thermal diffusion time shown in Table 2.

[0224] As shown in Figure 14, within the 1000s test time, when the hot surface temperature of cell A's large surface reached nearly 900°C within the first 700s, the temperature of cell B's large surface did not exceed 350°C, and the temperature on the back of cell B did not exceed 100°C due to the insulating effect of the composite thermal pad. During the first 700s, the temperature of cell B's large surface remained essentially at a temperature platform near 250°C, from the maximum temperature of cell A's large surface. The duration of this temperature platform (the temperature platform between the maximum temperature of cell A's large surface and the inflection point where the temperature of cell B's large surface rises) is the thermal diffusion time shown in Table 2.

[0225] It can be seen from Table 2 that when the thickness of the composite thermal insulation pads is the same, the thermal insulation performance of the composite thermal insulation pads of batteries 2 to 3 is better, and the thermal insulation performance of the composite thermal insulation pad of battery 2 is the best. For battery 2, which is a ternary lithium battery cell in which the atomic proportion of nickel in the 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 thermal insulation layer and the second thermal insulation layer are both 1.5mm~2.5mm. Furthermore, the capacity of the battery cell is 215Ah, which is within the range of battery cell capacity ≥150Ah and <200Ah. Optionally, the thickness of the composite phase change layer is 2.3mm~3.3mm, and the thickness of the first thermal insulation layer and the second thermal insulation layer are each independently 1.5mm~2mm.

[0226] In some embodiments, the film thickness of the above-mentioned composite thermal insulation pad can be obtained by simulation and screening using a heat estimation model. The thermal diffusion time (simulation value) of batteries 1 to 4 obtained by simulation of the heat estimation model is shown in Table 2, and the simulation test curves of the thermal insulation performance of batteries 2 and 3 are shown as curves 2a to 1d in Figures 13 and 14, respectively. By comparing the measured values ​​with the simulation values, it can be seen that the error between the two is within 15%. As shown in Table 2, the thickness composition of the composite thermal insulation pad is screened by the measured values ​​and / or simulation values ​​of the thermal diffusion time. The above Table 2 of this application is for different systems and capacities of battery cells, and the thickness of the composite thermal insulation pad is verified by actual measurement and heat estimation model simulation.

[0227] FIG15 shows a method for testing a battery using a heat estimation model. The test method can obtain test data, and a heat diffusion time simulation value can be obtained from the test data. The following description uses the method applied to the computer device in FIG16 as an example. The computer device can be a terminal, and its internal structure diagram can be shown in FIG16. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected via 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 operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner. The wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a battery testing method is implemented. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or may be a key, trackball, or touchpad provided on the computer device housing, or may be an external keyboard, touchpad, or mouse, etc. It will be understood by those skilled in the art that the structure shown in FIG16 is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. Specific computer devices may include more or fewer components than shown in the figure, or may combine certain components, or have a different arrangement of components.

[0228] The battery testing method using the thermal estimation model includes the following steps:

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

[0230] The input command is used to obtain the property parameters of the battery under test entered by the user on the test interface, which contains the property parameters of the battery under test. The property parameters are relevant for calculating the thermal diffusion performance of the battery. The test interface is the interface of the test application or simulation software, for example, when using a test app to test the battery, the test interface of the test app. This test application or simulation software can realize the construction of a simulation model for the battery and perform testing based on the simulation model.

[0231] In an embodiment of the present application, a test application (e.g., 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 battery, thereby guiding the design of the battery. When it is necessary to test a thermal runaway battery or a battery, a test application or simulation software for simulating the battery can be started on the computer device, and a test interface corresponding to the test application or simulation software can be displayed on the display screen of the computer device. The user can enter the attribute parameters of the battery to be tested on the test interface. After the user enters the attribute parameters, the computer device can generate an input instruction carrying the attribute parameters. The computer device can immediately respond to the input instruction triggered by the user on the test interface, parse the input instruction, extract the attribute parameters of the battery to be tested, and obtain the attribute parameters of the battery to be tested. Optionally, after the user enters the attribute parameters of the battery on the test interface, the computer device can also store the attribute parameters in a cache. When the computer device responds to the input instruction, the attribute parameters can be obtained from the cache according to the instruction of the input instruction.

[0232] S202 , responding to a test instruction triggered by the user on the test interface, inputting the attribute parameters into a heat estimation model for measurement, obtaining test data of the battery to be tested, and displaying the test data on the test interface.

[0233] Among them, the test instruction is used to start the test of the battery to be tested, that is, to test according to the property parameters and the heat estimation model, so as to realize the test of the simulated battery to be tested. The heat estimation model is used to measure the influence of the thermal diffusion of the battery according to the property 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. For example, the battery to be tested includes thermal runaway cell A and thermal runaway cell B. The test data includes the temperature change data of the large surface of the cell of thermal runaway cell A over time, the temperature change data of the bottom surface of the cell of thermal runaway cell A over time, the temperature change data of the large surface of the cell of thermal runaway cell B over time, and the temperature change data of the bottom surface of the cell of thermal runaway cell B over time. The heat estimation model can be pre-built and stored in a database, which can include various types of battery test models to provide calculation methods for battery performance testing. Optionally, the heat estimation model can be used to calculate the heat exchange heat group between the thermal runaway cell and the air in the battery under test, as well as to calculate the internal thermal resistance of the thermal runaway cell, so as to measure the thermal diffusion performance of the thermal runaway cell based on these two calculations.

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

[0235] Among them, ρ represents the density of the battery cell, C pIndicates the specific heat capacity of the battery cell, T indicates the temperature of the battery cell, τ indicates the test time of the battery cell, represents the rate of change of temperature over time, k represents the thermal conductivity, Represents the self-generated heat of the battery cell. The density, specific heat capacity, self-generated heat capacity, and thermal conductivity of the battery cell are all attribute parameters of the battery cell, and the computer equipment can calculate the battery cell density and specific heat capacity based on some geometric parameters of the battery cell. For example, the battery cell density and specific heat capacity can be calculated based on the battery cell length, battery cell width, battery cell height, battery cell side shell thickness, battery cell large surface shell thickness, battery cell bottom shell thickness, etc. Optionally, the battery cell density, battery cell specific heat capacity, battery cell thermal conductivity, and self-generated heat capacity of the battery cell can also be determined based on the battery cell's description document.

[0236] In an embodiment of the present application, when the computer device obtains the property parameters of the battery to be tested based on the aforementioned steps, the user can trigger the generation of a test instruction on the test interface by clicking a control, voice input, or text input. Optionally, the test instruction can include an identifier of a 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 further search the database for the heat estimation model based on the identifier of the heat estimation model. The property parameters of the battery to be tested are input into the heat estimation model for measurement, and the temperature change data of each surface of the thermal runaway cell in the battery to be tested is measured, that is, the test data is obtained.

[0237] The test method described in the embodiment of the present application obtains the property parameters of the battery to be tested by responding to the input instructions triggered by the user on the test interface, and inputs the property parameters into the heat estimation model for measurement in response to the test instructions triggered by the user on the test interface, obtains the test data of the battery to be tested, and displays the test data on the test interface. The above test method provides a simulation application that can test the battery to be tested, that is, by inputting the corresponding test instructions on the test interface of the application, the thermal runaway condition or thermal runaway heat dissipation condition of the battery to be tested can be tested according to user needs and using a preset heat estimation model. Compared with the traditional method of performing actual testing on the battery to be tested, the above method is a user-operable simulation test method that does not rely on the actual thermal runaway battery for testing. It can avoid the additional cost brought by design trial and error to a certain extent, and 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 be tested to a certain extent.

[0238] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0239] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by 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 ≥200Ah and <260Ah, and the first thermal insulation layer and the second thermal insulation layer are The thickness is 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 in the battery cell accounts for ≥70% of the atoms 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 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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