Battery case, battery cell and battery device

Abstract

The invention discloses a battery shell, a battery monomer and a battery device, the battery shell comprises a shell and an insulation protection layer, the insulation protection layer is arranged on the outer surface of the shell, the volume heat capacity of the insulation protection layer is s, and s is greater than or equal to 1 MJ / (m.K). According to the battery shell disclosed by the embodiment of the invention, the insulation protection layer is arranged on the outer surface of the shell, so that an insulation protection effect can be achieved; when the battery works, heat generated by the electrode assembly located in the battery shell is transferred to the insulation protection layer through the shell, and the volume heat capacity of the insulation protection layer is not smaller than 1 MJ / (m.K), so that when the insulation protection layer absorbs the same heat, the temperature rise amplitude is smaller, the heat buffering capacity is higher, and the heat stability is better; according to the invention, rapid accumulation of heat can be more effectively buffered, and rapid rise of temperature can be delayed, so that the heat dissipation effect can be improved, and the heat dissipation requirement of the battery can be well met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery shell, a battery monomer and a battery device. BACKGROUND

[0002] In the related art, an insulating protective layer is usually arranged on the outer surface of the battery shell to play an insulating protective role. However, the insulating protective layer arranged on the outer surface of the battery shell in the related art can play an insulating protective role, but it is difficult to better meet the heat dissipation requirements of the battery. Therefore, there is room for improvement. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a battery shell, wherein the insulating protective layer arranged on the outer surface of the shell can better meet the heat dissipation requirements of the battery while playing an insulating protective role.

[0004] The present application also provides a battery monomer having the above-mentioned battery shell.

[0005] The present application also provides a battery device having the above-mentioned battery monomer.

[0006] According to the battery shell of the first aspect of the present application, the insulating protective layer arranged on the outer surface of the shell can better meet the heat dissipation requirements of the battery while playing an insulating protective role.

[0007] According to the battery shell of the present application, the insulating protective layer arranged on the outer surface of the shell can play an insulating protective role. When the battery is working, the heat generated by the electrode assembly located in the battery shell is transmitted to the insulating protective layer through the shell. By making the volumetric heat capacity of the insulating protective layer not less than 1 MJ / (m3·K), the temperature rise of the insulating protective layer is smaller when absorbing the same amount of heat, and the insulating protective layer has stronger heat buffering capacity and better thermal stability. It can more effectively buffer the rapid accumulation of heat and delay the rapid rise of temperature, thereby improving the heat dissipation effect and better meeting the heat dissipation requirements of the battery.

[0008] According to some embodiments of the present application, the volumetric heat capacity of the insulating protective layer ranges from 1 MJ / (m3·K) to 3 MJ / (m3·K).

[0009] According to some embodiments of the present application, the thermal conductivity of the insulating protective layer is k, and k ranges from 0.1 W / (m·K) to 1 W / (m·K).

[0010] According to some embodiments of the present application, the thermal conductivity of the insulation protective layer is k, k satisfies: 200≤p / k≤300, wherein the unit of k is W / (m·K), and p is the mass energy density of the battery, the unit of p is Wh / kg.

[0011] According to some embodiments of the present application, the thickness of the insulation protective layer ranges from 60 μm to 200 μm.

[0012] According to some embodiments of the present application, the insulation protective layer is an insulation coating.

[0013] According to some embodiments of the present application, the insulation protective layer is a light-cured coating.

[0014] According to some embodiments of the present application, the insulation protective layer comprises a bottom layer and a surface layer which are arranged in a stack, and the bottom layer is located between the surface layer and the outer surface of the shell.

[0015] According to some embodiments of the present application, the absolute value of the difference between the thermal conductivities of the bottom layer and the surface layer is a thermal conductivity difference, the ratio of the thermal conductivity difference to the thermal conductivity of the bottom layer is less than 0.1, and the ratio of the thermal conductivity difference to the thermal conductivity of the surface layer is less than 0.1.

[0016] According to some embodiments of the present application, the thickness of the bottom layer is less than the thickness of the surface layer; and / or, the thickness of the bottom layer ranges from 10 μm to 50 μm, and the thickness of the surface layer ranges from 50 μm to 150 μm.

[0017] According to some embodiments of the present application, the bottom layer and the surface layer both comprise epoxy resin and polyurethane acrylic resin, the mass percentage of the epoxy resin in the bottom layer is greater than the mass percentage of the epoxy resin in the surface layer, and the mass percentage of the polyurethane acrylic resin in the surface layer is greater than the mass percentage of the polyurethane acrylic resin in the bottom layer.

[0018] The battery cell according to the second aspect of the embodiments of the present application comprises: a battery shell, the battery shell is the battery shell according to the first aspect of the embodiments of the present application; and an electrode assembly, the electrode assembly is arranged in the battery shell.

[0019] The battery cell according to the embodiments of the present application can effectively buffer the rapid accumulation of heat and delay the rapid rise of temperature when the battery cell is working, so as to improve the heat dissipation effect and meet the heat dissipation demand of the battery.

[0020] The battery device according to the third aspect of the embodiments of the present application comprises: a box; and a battery cell according to the second aspect of the embodiments of the present application, the battery cell is arranged in the box.

[0021] According to the battery device of the embodiment of the present application, by arranging the battery monomer, when the battery monomer is working, the rapid accumulation of heat can be more effectively buffered, the rapid rise of temperature is delayed, and thus the heat dissipation effect can be improved, and the heat dissipation requirement of the battery can be better met.

[0022] Additional aspects and advantages of the present application will be made apparent from the following description of embodiments that proceeds with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which: Figure 1 is a schematic diagram of a battery monomer according to some embodiments of the present application; Figure 2 is a schematic diagram of a battery shell according to some embodiments of the present application; Figure 3 is a partial sectional schematic diagram of a battery shell according to some embodiments of the present application; Figure 4 is a schematic diagram of a battery device according to some embodiments of the present application.

[0024] REFERENCE NUMERALS 100, battery monomer; 10, battery shell; 11, shell; 12, insulation protective layer; 121, bottom layer; 122, surface layer; 21, electrode terminal; 200, battery device; 30, box. DETAILED DESCRIPTION

[0025] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which examples of the embodiments are shown, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0026] Reference is made below Figures 1-3 A battery shell 10 according to an embodiment of the present application is described.

[0027] Reference is made to Figures 1-3 According to the battery shell 10 of the first aspect embodiment of the present application, the battery shell 10 comprises a shell 11 and an insulation protective layer 12, and the insulation protective layer 12 is arranged on the outer surface of the shell 11. The shell 11 can be a metal piece, for example, the shell 11 can be a steel shell, an aluminum shell, an aluminum alloy shell, or a titanium alloy shell, etc.

[0028] The insulation protective layer 12 has good insulation performance. For example, at least part of the insulation protective layer 12 can be resin. For example, the insulation protective layer 12 can be a pre-prepared insulation film, and then the insulation film is bonded and fixed on the outer surface of the shell 11. The insulation protective layer 12 can also be an insulation coating, which can be formed on the outer surface of the shell 11 by spraying. By covering the insulation protective layer 12 with insulation performance on the outer surface of the shell 11, the insulation protective effect on the battery can be achieved.

[0029] The volume heat capacity of the insulation protective layer 12 is s, and s satisfies s≥1 MJ / (m³·K). For example, the volume heat capacity s of the insulation protective layer 12 can be 1 MJ / (m³·K), 1.2 MJ / (m³·K), 1.4 MJ / (m³·K), 1.5 MJ / (m³·K), 1.6 MJ / (m³·K), 1.8 MJ / (m³·K), 2 MJ / (m³·K), 2.1 MJ / (m³·K), 2.2 MJ / (m³·K), 2.4 MJ / (m³·K), 2.5 MJ / (m³·K), 2.7 MJ / (m³·K), 3 MJ / (m³·K), etc.

[0030] When the battery is working, the heat generated by the electrode assembly located in the battery shell 10 is transmitted to the insulation protective layer 12 through the shell 11. The insulation protective layer 12 can absorb the heat generated by the battery. By making the volume heat capacity of the insulation protective layer 12 not less than 1 MJ / (m³·K), the temperature rise of the insulation protective layer 12 is smaller when absorbing the same amount of heat, and the insulation protective layer 12 has stronger heat buffering capacity and better thermal stability, which can more effectively buffer the rapid accumulation of heat and delay the rapid rise of temperature, thereby improving the heat dissipation effect and better meeting the heat dissipation demand of the battery.

[0031] According to the battery shell 10 of the embodiment of the present application, the insulation protective layer 12 is arranged on the outer surface of the shell 11, which can achieve the insulation protective effect. When the battery is working, the heat generated by the electrode assembly located in the battery shell 10 is transmitted to the insulation protective layer 12 through the shell 11. By making the volume heat capacity of the insulation protective layer 12 not less than 1 MJ / (m³·K), the temperature rise of the insulation protective layer 12 is smaller when absorbing the same amount of heat, and the insulation protective layer 12 has stronger heat buffering capacity and better thermal stability, which can more effectively buffer the rapid accumulation of heat and delay the rapid rise of temperature, thereby improving the heat dissipation effect and better meeting the heat dissipation demand of the battery.

[0032] According to some embodiments of the present application, the volume heat capacity of the insulation protective layer 12 is in the range of 1 MJ / (m3·K) to 3 MJ / (m3·K). When the battery needs to dissipate heat, the insulation protective layer 12 can absorb the heat generated by the battery. By setting the volume heat capacity of the insulation protective layer 12 to be not less than 1 MJ / (m3·K), the temperature rise of the insulation protective layer 12 when absorbing the same amount of heat is smaller, so that the insulation protective layer 12 has stronger heat buffering capacity and better thermal stability, can more effectively buffer the rapid accumulation of heat and delay the rapid rise of temperature, thereby improving the heat dissipation effect and better meeting the heat dissipation needs of the battery. When the external environment temperature is low and the battery needs to be heated by a heating film, by setting the volume heat capacity of the insulation protective layer 12 to be not more than 3 MJ / (m3·K), the temperature rise of the insulation protective layer 12 when absorbing the heat generated by the heating film and transferring the heat to the electrode assembly in the battery shell 10 is not too small to affect the heating efficiency of the battery. By setting the volume heat capacity of the insulation protective layer 12 in the range of 1 MJ / (m3·K) to 3 MJ / (m3·K), the heat dissipation needs of the battery and the heating efficiency of the battery can be better balanced.

[0033] According to some embodiments of the present application, the thermal conductivity of the insulation protective layer 12 is k, and the value of k is in the range of 0.1 W / (m·K) to 1 W / (m·K). For example, the value of the thermal conductivity k of the insulation protective layer 12 can be 0.1 W / (m·K), 0.2 W / (m·K), 0.3 W / (m·K), 0.4 W / (m·K), 0.5 W / (m·K), 0.6 W / (m·K), 0.7 W / (m·K), 0.8 W / (m·K), 0.9 W / (m·K), 1 W / (m·K), etc.

[0034] By setting the thermal conductivity of the insulation protective layer 12 to be not less than 0.1 W / (m·K), the insulation protective layer 12 has better heat dissipation efficiency, so that when the battery needs to dissipate heat, the heat generated in the battery shell 10 is transferred to the insulation protective layer 12 through the shell 11, the insulation protective layer 12 can quickly absorb the heat generated by the battery and dissipate the absorbed heat, and the heat dissipation needs of the battery can be better met. By setting the thermal conductivity of the insulation protective layer 12 to be not more than 1 W / (m·K), the excessive heat loss of the battery in a low temperature environment due to the too high thermal conductivity of the insulation protective layer 12 can be avoided. By setting the thermal conductivity of the insulation protective layer 12 in the range of 0.1 W / (m·K) to 1 W / (m·K), the heat dissipation needs in high temperature environment or high power charging and discharging conditions can be better balanced, and excessive heat loss in a low temperature environment can be better avoided.

[0035] According to some embodiments of the present application, the thermal conductivity of the insulation protective layer 12 is k, and k satisfies: 200≤p / k≤300, where the unit of k is W / (m·K), and p is the mass energy density of the battery, and the unit of p is Wh / kg. For example, the value of p / k can be 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, etc. By setting the ratio of the thermal conductivity of the insulation protective layer 12 to the mass energy density of the battery in the range of 200-300, the thermal conductivity of the insulation protective layer 12 is more matched with the mass energy density of the battery. When setting the thermal conductivity of the insulation protective layer 12, the mass energy density of the battery can be designed, so that the insulation protective layer 12 on the battery shell 10 can better meet the corresponding heat dissipation requirements.

[0036] According to some embodiments of the present application, referring to Figure 3 , the thickness of the insulation protective layer 12 ranges from 60 μm to 200 μm. For example, the thickness of the insulation protective layer 12 is d0, and d0 can be 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, etc. By setting the thickness of the insulation protective layer 12 in the range of 60 μm to 200 μm, the insulation protective layer 12 can better cover the outer surface of the shell 11 to ensure the insulation protection performance. In addition, the use of the insulation protective layer 12 and the volume of the battery shell 10 can be reduced, and the insulation protective layer 12 can also avoid being too thick to reduce the heat dissipation efficiency.

[0037] According to some embodiments of the present application, the insulation protective layer 12 is an insulation coating. By setting the insulation protective layer 12 as an insulation coating, the insulation protective layer 12 can be sprayed or coated on the outer surface of the shell 11. The adhesion between the insulation protective layer 12 and the shell 11 is stronger, and the insulation protective layer 12 is less likely to fall off from the shell 11 and has better scratch resistance. The insulation performance is not easy to fail, and the insulation protective layer 12 can play a stable and reliable insulation protection role. In addition, the insulation protective layer 12 formed by spraying is closely combined with the outer surface of the shell 11, reducing the contact thermal resistance between the insulation protective layer 12 and the shell 11. Compared with the traditional PET insulation film, no bubbles are generated between the insulation protective layer 12 formed by spraying on the outer surface of the shell 11 and the outer surface of the shell 11, further reducing the heat transfer resistance between the insulation protective layer 12 and the shell 11, which is beneficial to improving the heat dissipation performance of the battery and better meeting the heat dissipation requirements of the battery.

[0038] According to some embodiments of the present application, the insulation protective layer 12 is a photocuring coating. By setting the insulation coating as a photocuring coating, the photocuring coating has fast curing speed, high production efficiency, and high-quality coating with excellent coating performance.

[0039] According to some embodiments of the present application, referring to Figure 3 The insulating protective layer 12 comprises a bottom layer 121 and a surface layer 122 arranged in a stack, and the bottom layer 121 is located between the surface layer 122 and the outer surface of the shell 11. In the process of spraying the insulating protective layer 12 on the outer surface of the shell 11, the bottom layer 121 can be sprayed on the outer surface of the shell 11 first, and then the surface layer 122 is sprayed on the bottom layer 121. The bottom layer 121 can be one layer or a plurality of layers arranged in a stack, and the surface layer 122 can be one layer or a plurality of layers arranged in a stack.

[0040] The bottom layer 121 and the surface layer 122 both have insulating properties, for example, the insulating properties of the surface layer 122 can be better than those of the bottom layer 121, and the adhesion between the bottom layer 121 and the shell 11 can be better than that between the surface layer 122 and the shell 11.

[0041] By arranging the insulating protective layer 12 covering the outer surface of the shell 11 to comprise a bottom layer 121 and a surface layer 122 arranged in a stack, the adhesion between the insulating protective layer 12 and the shell 11 can be further enhanced, and the material composition of the bottom layer 121 and the surface layer 122 can be arranged as needed to better meet the adhesion requirements between the insulating protective layer 12 and the shell 11 and the protective insulating properties of the insulating protective layer 12.

[0042] For example, the volumetric heat capacity of the bottom layer 121 is not less than 1 MJ / (m³·K), and the volumetric heat capacity of the surface layer 122 is not less than 1 MJ / (m³·K). Further, the volumetric heat capacity of the bottom layer 121 ranges from 1 MJ / (m³·K) to 3 MJ / (m³·K), and the volumetric heat capacity of the surface layer 122 ranges from 1 MJ / (m³·K) to 3 MJ / (m³·K).

[0043] For example, the thermal conductivity of the bottom layer 121 ranges from 0.1 W / (m·K) to 1 W / (m·K), and the thermal conductivity of the surface layer 122 ranges from 0.1 W / (m·K) to 1 W / (m·K).

[0044] According to some embodiments of the present application, the absolute value of the difference between the thermal conductivities of the bottom layer 121 and the surface layer 122 is the thermal conductivity difference, and the ratio of the thermal conductivity difference to the thermal conductivity of the bottom layer 121 is less than 0.1, and the ratio of the thermal conductivity difference to the thermal conductivity of the surface layer 122 is less than 0.1. For example, when the thermal conductivity of the bottom layer 121 is greater than that of the surface layer 122, the difference between the thermal conductivities of the bottom layer 121 and the surface layer 122 is positive; when the thermal conductivity of the bottom layer 121 is less than that of the surface layer 122, the difference between the thermal conductivities of the bottom layer 121 and the surface layer 122 is negative; and when the thermal conductivity of the bottom layer 121 is equal to that of the surface layer 122, the difference between the thermal conductivities of the bottom layer 121 and the surface layer 122 is 0.

[0045] For example, the ratio of the thermal conductivity difference to the thermal conductivity of the bottom layer 121 can be 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0, etc.; the ratio of the thermal conductivity difference to the thermal conductivity of the surface layer 122 can be 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0, etc.

[0046] By making the ratio of the thermal conductivity difference to any one of the bottom layer 121 and the surface layer 122 less than 0.1, the thermal conductivities of the bottom layer 121 and the surface layer 122 can be close or the same, making the thermal conductivity of the entire insulating protective layer 12 more uniform, which helps to evenly distribute heat throughout the coating, avoiding local overheating or overcooling, thereby improving heat dissipation effect; and uniform thermal conductivity can reduce the thermal resistance between the bottom layer 121 and the surface layer 122, allowing heat to be more smoothly transferred from the shell 11 to the external environment, improving heat dissipation efficiency.

[0047] According to some embodiments of the application, the thickness of the bottom layer 121 is less than the thickness of the surface layer 122. By making the thickness of the bottom layer 121 less than the thickness of the surface layer 122, when the bottom layer 121 is sprayed on the outer surface of the shell 11, the adhesion of the bottom layer 121 to the outer surface of the shell 11 can be stronger than if the thickness of the bottom layer 121 is too thick, and the cracking and cost problems caused by the large thickness of the bottom layer 121 can be reduced.

[0048] According to some embodiments of the application, with reference to Figure 3 , the thickness of the surface layer 122 ranges from 50 μm to 150 μm. For example, the thickness of the surface layer 122 is d1, and d1 can be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, etc. By setting the thickness of the surface layer 122 to be 50 μm to 150 μm, the appropriate thickness of the surface layer 122 can ensure the uniformity and insulation performance of the coating, while preventing corrosion of the battery cell by the external environment.

[0049] According to some embodiments of the application, with reference to Figure 3The thickness of the bottom layer 121 ranges from 10 μm to 50 μm. For example, the thickness of the bottom layer 121 is d2, and d2 can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or the like. By setting the thickness of the bottom layer 121 to range from 10 μm to 50 μm, the insulation effect can be ensured, and the adhesion can be ensured, and the risk of cracking of the bottom layer 121 can be reduced.

[0050] According to some embodiments of the present application, the bottom layer 121 and the surface layer 122 both include epoxy resin and polyurethane acrylic resin, the mass ratio of the epoxy resin in the bottom layer 121 is greater than the mass ratio of the epoxy resin in the surface layer 122, and the mass ratio of the polyurethane acrylic resin in the surface layer 122 is greater than the mass ratio of the polyurethane acrylic resin in the bottom layer 121. Both the epoxy resin and the polyurethane acrylic resin have good insulation performance, so that the bottom layer 121 and the surface layer 122 both have good insulation performance. The adhesion of the epoxy resin is better than that of the polyurethane acrylic resin, and the adhesion of the epoxy resin to the metal substrate is stronger, and the weather resistance of the polyurethane acrylic resin is better than that of the epoxy resin.

[0051] By making the mass ratio of the epoxy resin in the bottom layer 121 greater than the mass ratio of the epoxy resin in the surface layer 122, the adhesion between the bottom layer 121 and the shell 11 can be stronger, so that the insulation protective layer 12 is not easy to fall off from the shell 11. The surface layer 122 is the part of the insulation protective layer 12 exposed to the outside, and by making the mass ratio of the polyurethane acrylic resin in the surface layer 122 greater than the mass ratio of the polyurethane acrylic resin in the bottom layer 121, the surface layer 122 has good weather resistance, which is conducive to improving the stability of the insulation protective layer 12 and prolonging the service life of the insulation protective layer 12.

[0052] According to the battery cell 100 of the second aspect of the embodiments of the present application, the battery cell 100 includes a battery shell 10 and an electrode assembly. The battery shell 10 is the battery shell 10 according to the first aspect of the embodiments of the present application, and the electrode assembly is arranged in the battery shell 10.

[0053] The battery shell 10 is provided with an electrode terminal 21, and an electrode assembly is arranged in the battery shell 10 and connected with the electrode terminal 21. The electrode assembly can include a positive electrode tab, a negative electrode tab and an insulating separator arranged between the positive electrode tab and the negative electrode tab. The electrode assembly includes a positive electrode lug and a negative electrode lug, and the battery shell 10 can be provided with two electrode terminals 21, one of which is positive and the other of which is negative, and the positive electrode lug and the negative electrode lug are respectively connected with the electrode terminal 21 of the same polarity.

[0054] According to the battery monomer 100 of the embodiment of the application, by arranging the battery shell 10, when the battery monomer 100 works, the rapid accumulation of heat can be more effectively buffered, and the rapid rise of temperature is delayed, so that the heat dissipation effect can be improved, and the heat dissipation requirement of the battery can be better met.

[0055] According to the battery device 200 of the third aspect of the embodiment of the application, the battery device 200 includes a box body 30 and a battery monomer 100, the battery monomer 100 is the battery monomer 100 according to the second aspect of the embodiment of the application, and the battery monomer 100 is arranged in the box body 30. The battery monomer 100 can be multiple, and the multiple battery monomers 100 can be assembled into a battery module and placed in the box body 30.

[0056] For example, the battery device 200 can be used in an energy storage device.

[0057] According to the battery device 200 of the embodiment of the application, by arranging the battery monomer 100, when the battery monomer 100 works, the rapid accumulation of heat can be more effectively buffered, and the rapid rise of temperature is delayed, so that the heat dissipation effect can be improved, and the heat dissipation requirement of the battery can be better met.

[0058] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0059] In the description of the application, "first feature" and "second feature" can include one or more features.

[0060] In the description of the application, "multiple" means two or more.

[0061] In the description of the application, a first feature being "on", "above", or "on top" of a second feature can include the first and second features being directly in contact, or the first and second features not being directly in contact but being in contact through another feature between them.

[0062] In the description of the application, a first feature being "on", "above", and "on top" of a second feature includes the first feature being directly on, above, and on top of the second feature, or only indicating the first feature being horizontally higher than the second feature.

[0063] In the description of the application, the description of the reference terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description of the application, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made hereto without departing from the principles and spirit of the application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery casing, characterized in that, include: case; An insulating protective layer is disposed on the outer surface of the shell, and the volumetric heat capacity of the insulating protective layer is s, which satisfies: s≥1 MJ / (m³·K).

2. The battery casing according to claim 1, characterized in that, The volumetric heat capacity of the insulating protective layer ranges from 1 MJ / (m³·K) to 3 MJ / (m³·K).

3. The battery casing according to claim 1, characterized in that, The thermal conductivity of the insulating protective layer is k, and the value of k ranges from 0.1 W / (m·K) to 1 W / (m·K).

4. The battery casing according to claim 1, characterized in that, The thermal conductivity of the insulating protective layer is k, which satisfies: 200≤ρ / k≤300, where the unit of k is W / (m·K), and ρ is the mass energy density of the battery, with the unit of ρ being Wh / kg.

5. The battery casing according to claim 1, characterized in that, The thickness of the insulating protective layer ranges from 60μm to 200μm.

6. The battery casing according to any one of claims 1-5, characterized in that, The insulating protective layer is an insulating coating.

7. The battery casing according to claim 6, characterized in that, The insulating protective layer is a photocurable coating.

8. The battery casing according to claim 6, characterized in that, The insulating protective layer includes a bottom layer and a top layer stacked together, with the bottom layer located between the top layer and the outer surface of the housing.

9. The battery casing according to claim 8, characterized in that, The absolute value of the difference in thermal conductivity between the bottom layer and the top layer is the thermal conductivity difference. The ratio of the thermal conductivity difference to the thermal conductivity of the bottom layer is less than 0.1, and the ratio of the thermal conductivity difference to the thermal conductivity of the top layer is less than 0.

1.

10. The battery casing according to claim 8, characterized in that, The thickness of the bottom layer is less than the thickness of the top layer; and / or, the thickness of the bottom layer ranges from 10 μm to 50 μm, and the thickness of the top layer ranges from 50 μm to 150 μm.

11. The battery casing according to claim 8, characterized in that, Both the bottom layer and the top layer comprise epoxy resin and polyurethane acrylate resin. The epoxy resin in the bottom layer has a higher mass percentage than the epoxy resin in the top layer, and the polyurethane acrylate resin in the top layer has a higher mass percentage than the polyurethane acrylate resin in the bottom layer.

12. A single battery cell, characterized in that, include: A battery casing, wherein the battery casing is the battery casing according to any one of claims 1-11; An electrode assembly is disposed within the battery casing.

13. A battery device, characterized in that, include: Box; According to claim 12, the battery cell is disposed within the housing.

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