Battery cell, battery, and electric device

Abstract

The present application relates to a battery cell, a battery, and an electric device. The battery cell comprises: a housing having an opening; a cell assembly accommodated in the housing; an end cover provided at the opening in a sealing manner; electrode terminals provided on the end cover and used for connecting to the cell assembly; and rubber sealing members provided between the electrode terminals and the end cover in a sealing manner, the rubber sealing members comprising hydrogenated nitrile butadiene rubber, and the hydrogenated nitrile butadiene rubber having a weight average molecular weight of 100 thousand to 1 million.

Description

Battery cell, battery and electric device

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 2024113374124, filed on September 24, 2024, and entitled "Battery cell, battery and electric device", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

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

[0004] Batteries are widely used in various consumer electronic products and electric vehicles due to their outstanding characteristics such as light weight, no pollution, no memory effect, etc. In order to seal the structure of the battery, sealing materials are needed, for example, an electrode terminal for connecting with the cell assembly needs to be arranged on the end cover of the battery cell, and the sealing between the electrode terminal and the end cover is particularly important, so a sealing member needs to be arranged.

[0005] Fluororubber is widely used in the sealing of batteries due to its excellent performance. However, the fluorine atoms in fluororubber have strong polarity and large intermolecular forces, which makes the glass transition temperature of fluororubber relatively high, and the elastic modulus and tensile strength will sharply decrease when encountering low temperature, resulting in the decrease of the service life and sealing performance of the sealing material.

[0006] In addition, fluororubber contains fluorine elements, which can cause pollution damage to the ecological environment and harm to human health.

[0007] Therefore, the traditional technology needs to be improved. SUMMARY

[0008] Therefore, it is necessary to provide a battery cell, a battery and an electric device, which have good low-temperature resistance, insulation and chemical resistance, especially electrolyte swelling resistance, so as to improve the service life of the battery and the battery cell.

[0009] In a first aspect, the present application provides a battery cell, comprising:

[0010] a housing having an opening;

[0011] a cell assembly accommodated in the housing;

[0012] an end cover sealingly arranged in the opening;

[0013] an electrode terminal arranged on the end cover and used for connecting with the cell assembly; and

[0014] A rubber seal is arranged between the electrode terminal and the end cover; the rubber seal comprises hydrogenated nitrile rubber, and the hydrogenated nitrile rubber has a weight average molecular weight of 100,000-1,000,000.

[0015] Therefore, the rubber seal applied to the battery cell of the application comprises hydrogenated nitrile rubber (HNBR) having a specific weight average molecular weight, the hydrogenated nitrile rubber (HNBR) is in a solid state, the rubber seal prepared by using the hydrogenated nitrile rubber having the specific weight average molecular weight has good low-temperature resistance, insulation performance and chemical resistance, in particular, electrolyte swelling resistance, and thus can provide good sealing performance, so as to improve the service life of the battery and the battery cell.

[0016] In some embodiments of the application, the hydrogenated nitrile rubber has a weight average molecular weight of 200,000-450,000. The hydrogenated nitrile rubber has a weight average molecular weight in the range, so that the rubber seal prepared therefrom has good low-temperature resistance, insulation performance, and further improved elongation at break and chemical resistance, in particular, electrolyte swelling resistance, and thus improves the service life of the battery and the battery cell.

[0017] In some embodiments of the application, at least one of the following conditions is met:

[0018] (1) the hydrogenated nitrile rubber has an acrylonitrile content of 15wt%-45wt%;

[0019] (2) the hydrogenated nitrile rubber has a hydrogenation degree of ≥80%.

[0020] The higher the acrylonitrile content of the hydrogenated nitrile rubber, the higher the tensile strength, heat resistance, oil resistance, air tightness and hardness, but the low-temperature resistance is reduced, so that the acrylonitrile content of the hydrogenated nitrile rubber is further controlled in the range on the basis of the above preparation raw material ratio, so that the rubber seal prepared therefrom has better low-temperature resistance, insulation performance and chemical resistance, in particular, electrolyte swelling resistance.

[0021] The hydrogenation degree of the hydrogenated nitrile rubber in the range can have better heat resistance, low-temperature resistance, ozone resistance, chemical resistance and mechanical strength.

[0022] In some embodiments of the application, the preparation raw material of the rubber seal comprises hydrogenated nitrile rubber, reinforcing filler, insulating filler, processing aid, vulcanizing agent, vulcanizing activator and vulcanizing aid.

[0023] The rubber seal adopts hydrogenated nitrile rubber (HNBR) with a specific weight average molecular weight and is combined with reinforcing fillers, insulating fillers, processing aids, vulcanizing agents, vulcanizing activators and vulcanizing aids. Appropriately increasing the weight average molecular weight of the HNBR can improve the physical and mechanical properties of the rubber, such as tensile strength and wear resistance, and the rubber seal has good heat resistance and aging resistance. However, the HNBR with a high weight average molecular weight usually has a large viscosity, and a higher energy is required to slow down the vulcanization speed during processing, which can adversely affect the performance of the rubber seal after vulcanization. Therefore, by using the above preparation raw materials and controlling the weight average molecular weight within the above range, the processing performance of the HNBR rubber product can be improved, and the rubber seal prepared has good low-temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance. In addition, the rubber seal also has good mechanical properties, high-temperature resistance and compression resistance, thereby improving the service life of the rubber seal, the battery and the battery cell.

[0024] In some embodiments of the present application, in the preparation raw materials, the hydrogenated nitrile rubber is 100 parts, the reinforcing filler is 30-70 parts, the insulating filler is 10-30 parts, the processing aid is 5-15 parts, the vulcanizing agent is 3-10 parts, the vulcanizing activator is 5-15 parts, and the vulcanizing aid is 0.5-4 parts. Controlling the above preparation raw materials within the above range can improve the processing performance of the HNBR rubber product, and the rubber seal prepared has further improved elongation at break under the condition of good low-temperature resistance, insulation performance, electrolyte swelling resistance and compression resistance, thereby improving the service life of the rubber seal, the battery and the battery cell.

[0025] In some embodiments of the present application, in the preparation raw materials, the hydrogenated nitrile rubber is 100 parts, the reinforcing filler is 40-60 parts, the insulating filler is 10-15 parts, the processing aid is 8-12 parts, the vulcanizing agent is 5-8 parts, the vulcanizing activator is 7-10 parts, and the vulcanizing aid is 2-3 parts. Controlling the components of the above preparation raw materials within the range can further improve the elongation at break and chemical resistance, especially electrolyte swelling resistance, of the rubber seal prepared on the basis of good low-temperature resistance and insulation performance, thereby further improving the service life of the battery and the battery cell.

[0026] In some embodiments of the present application, the reinforcing filler includes at least one of carbon black, white carbon black, calcium carbonate, talc powder, mica powder and montmorillonite.

[0027] In some embodiments of the present application, the insulating filler includes at least one of barium sulfate and kaolin. The use of a compounded insulating filler can improve the insulation performance of the rubber seal.

[0028] In some embodiments of the present application, the processing aid includes at least one of a fatty acid derivative and an organic acid ester compound.

[0029] In some embodiments of the present application, at least one of the following conditions is satisfied:

[0030] (1) the fatty acid derivative includes at least one of stearic acid, zinc stearate, magnesium stearate, calcium stearate, potassium stearate, and sodium stearate;

[0031] (2) the organic acid ester compound includes at least one of trioctyl trimellitate, diisononyl phthalate, and di(2-ethyl)hexyl phthalate.

[0032] In some embodiments of the present application, at least one of the following conditions is satisfied:

[0033] (1) the vulcanization active agent includes a metal oxide;

[0034] (2) the vulcanization agent includes at least one of a peroxide vulcanization agent, a sulfur vulcanization agent, and a metal oxide vulcanization agent;

[0035] (3) the co-vulcanization agent includes at least one of zinc dimethyl acrylate, triallyl cyanurate, triallyl isocyanurate, and bismaleimide.

[0036] In some embodiments of the present application, at least one of the following conditions is satisfied:

[0037] (1) the metal oxide includes at least one of zinc oxide and magnesium oxide;

[0038] (2) the peroxide vulcanization agent includes at least one of dicumyl peroxide, di(tert-butylperoxy isopropyl) benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane.

[0039] In some embodiments of the present application, the preparation of the rubber seal includes the following steps:

[0040] mixing the preparation raw materials to obtain a rubber compound;

[0041] vulcanizing and forming the rubber compound to obtain a rubber seal.

[0042] In some embodiments of the present application, the temperature of the vulcanizing and forming is 140°C to 200°C, and the pressure of the vulcanizing and forming is 8MPa to 20MPa.

[0043] In some embodiments of the present application, the rubber seal has a mass change rate <40% and a volume expansion rate <40% after being soaked in a dimethyl carbonate solvent at 70°C for 72h.

[0044] In some embodiments of the present application, the compression permanent set of the rubber seal is < 30% after compression at 120°C for 9 days, according to the national standard GB / T 7759.1.

[0045] In some embodiments of the present application, the volume resistivity of the rubber seal is > 1*10 10 Ω·cm at a test voltage of 500V, according to the national standard GBT 31838.2-2019.

[0046] In some embodiments of the present application, the tensile strength of the rubber seal is ≥ 14.0 MPa, and the elongation at break is ≥ 130%.

[0047] In some embodiments of the present application, the battery monomer further comprises an electrolyte, the electrolyte is arranged in the shell, and the battery monomer is soaked in the electrolyte.

[0048] In a second aspect of the present application, a battery is provided, comprising the battery monomer of the first aspect of the present application.

[0049] In a third aspect of the present application, a power utilization device is provided, comprising at least one of the battery monomer of the first aspect of the present application and the battery of the second aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the present application, the drawings used in the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0051] FIG. 1 is a schematic diagram of a power utilization device using the battery of an embodiment of the present application as a power source;

[0052] FIG. 2 is an exploded structural diagram of the battery of an embodiment of the present application shown in FIG. 1;

[0053] FIG. 3 is an exploded structural diagram of a battery monomer in the battery of an embodiment of the present application;

[0054] FIG. 4 is a top view of the battery monomer in the battery of an embodiment of the present application;

[0055] FIG. 5 is an exploded structural diagram of an end cover, an electrode terminal, and a rubber seal of the battery monomer shown in FIG. 4;

[0056] FIG. 6 is a partial sectional view of the end cover of the battery monomer shown in FIG. 4 along line A-A.

[0057] Reference signs: 1000, electric device; 100, battery; 200, controller; 300, motor; 20, battery cell; 21, end cap; 22, housing; 23, electrode assembly; 21a, electrode terminal; 23a, tab; 231, mounting hole; 25, rubber seal. DETAILED DESCRIPTION

[0058] Hereinafter, specific embodiments of the battery, the manufacturing method, and the electric device of the present application are described in detail with appropriate reference to the accompanying drawings. However, there are cases where unnecessary detailed description is omitted. For example, there are cases where detailed description of matters that are well known, repeated description of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided so that those skilled in the art can fully understand the present application, and are not intended to limit the subject matter recited in the claims.

[0059] The "ranges" disclosed in the present application are defined in the form of lower and upper limits, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise specified, the numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when it is stated that a certain parameter is an integer ≥ 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0061] If not specifically stated, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0062] If not otherwise specified, all steps of the present application can be carried out in sequence or randomly, preferably in sequence. For example, the method comprising steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method can further comprise step (c) means that step (c) can be added to the method in any sequence, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0063] Unless otherwise specified, the terms used in the present application have the commonly understood meanings by those skilled in the art. Unless otherwise specified, the values of the parameters mentioned in the present application can be measured by various measuring methods commonly used in the art (for example, the test can be carried out according to the method given in the examples of the present application).

[0064] At present, from the development of market situation, the application of power battery is more and more widely. Power battery is not only applied to energy storage power supply system such as hydroelectric, thermal, wind and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of power battery, the demand of its market is also increasing.

[0065] The skilled person of the present application notices that the sealing of electrolyte in the battery monomer is particularly important, and the sealing element arranged between the electrode terminal and the end cover is the key material related to the sealing performance. At present, the main material of the sealing element is fluororubber, however, on the one hand, fluororubber contains fluorine element, which will cause pollution damage to the ecological environment and harm to human health, on the other hand, the low temperature performance of fluororubber is not good. The main deficiency of the sealing material currently applied to the battery is that the chemical resistance, especially the electrolyte swelling resistance, is not good, and the sealing material absorbs the electrolyte in the battery and swells after a period of use, thus leading to the decrease of the service life and sealing performance of the sealing material.

[0066] Therefore, the present application proposes a new rubber sealing element applied to the battery monomer, which not only does not contain fluorine element, but also has good low temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance, so as to improve the service life of the battery and the battery monomer.

[0067] The battery monomer disclosed in the embodiments of the present application can be used in, but not limited to, electric devices such as vehicles, ships or aircraft. The power supply system of the electric device can be composed of the battery monomer and the battery disclosed in the present application, so as to improve the sealing performance of the battery monomer and the service life of the battery and the battery monomer.

[0068] The embodiments of the present application provide a power consumption device using a battery as a power supply. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0069] The following embodiments are described by taking a power consumption device of an embodiment of the present application as a vehicle 1000 for example for convenience of description.

[0070] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile. The new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile. The vehicle 1000 is internally provided with a battery 100. The battery 100 can be arranged at a bottom, a head, or a tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power demand of the vehicle 1000 during starting, navigation, and driving.

[0071] In some embodiments of the present application, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000. Referring to FIG. 2, an embodiment of the present application provides a battery 100. Referring to FIG. 2, the battery monomer 20 includes a box body 10 and one or more battery monomers 20 arranged in the box body 10.

[0072] The box body 10 is used to provide an accommodation space for the battery monomer 20. The box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first part 11 and a second part 12. The first part 11 and the second part 12 are mutually covered, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the battery monomer 20. The second part 12 can be a hollow structure with one end open. The first part 11 can be a plate-shaped structure, and the first part 11 covers the open side of the second part 12 to jointly define the accommodation space with the second part 12. The first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder, a cuboid, and the like.

[0073] In the battery 100, the battery cells 20 can be multiple, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection, where the mixed connection means that the multiple battery cells 20 are connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and the whole of the multiple battery cells 20 is accommodated in the case 10. Of course, the battery 100 can also be that the multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and the whole is accommodated in the case 10. The battery 100 can also include other structures, for example, the battery 100 can also include a current combing component for realizing the electrical connection between the multiple battery cells 20.

[0074] Each of the battery cells 20 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0075] Please refer to FIG. 3, which is an exploded structural schematic diagram of the battery cell 20 provided by some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes a battery. Referring to FIG. 3, the battery cell 20 includes an end cover 21, a shell 22, and a cell assembly 23.

[0076] The end cover 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 21 can be adapted to the shape of the shell 22 to fit the shell 22. Optionally, the end cover 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cover 21 is not easy to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher structural strength, and the safety performance can also be improved. The end cover 21 can be provided with functional components such as an electrode terminal 21a. The electrode terminal 21a can be used to electrically connect with the cell assembly 23 for outputting or inputting the electrical energy of the battery cell 20. In some embodiments, the end cover 21 can also be provided with a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cover 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations thereon.

[0077] The shell 22 is a component for cooperating with the end cover 21 to form an internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte and other components. The shell 22 and the end cover 21 can be independent components, and an opening can be provided on the shell 22, and the end cover 21 is used to cover the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 21 and the shell 22 can also be integrated, specifically, the end cover 21 and the shell 22 can form a common connecting surface before other components enter the shell, and when it is necessary to seal the internal environment of the shell 22, the end cover 21 is used to cover the shell 22. The shell 22 can be various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations.

[0078] The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 2000, and is a basic unit capable of realizing mutual conversion between chemical energy and electrical energy. One or more electrode assemblies 23 can be contained in the shell 22. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have a portion with active material constituting a main body of the electrode assembly, and a portion without active material of the positive electrode sheet and the negative electrode sheet respectively constitutes a tab 23a. The positive electrode tab and the negative electrode tab can be located at one end of the main body or at two ends of the main body respectively. In the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tab 23a is connected to the electrode terminal 21a to form a current loop.

[0079] Please refer to FIG. 4, FIG. 5 and FIG. 6, the battery cell 20 further comprises an electrode terminal 21a and a rubber seal 25. The electrode terminal 21a is provided on the end cover 21 and is used to connect with the electrode assembly 23. The rubber seal 25 is provided between the electrode terminal 21a and the end cover 21. The rubber seal 25 not only has a sealing effect, but also has an insulating effect, avoiding conduction between the electrode terminal 21a and the end cover 21.

[0080] Further, the end cover 21 is provided with a mounting hole 231, and the electrode terminal 21a is provided on the end cover 21 through the mounting hole 231 and connected with the electrode assembly 23 in the internal environment of the shell 22.

[0081] The rubber seal 25 comprises hydrogenated nitrile rubber, and the weight average molecular weight of the hydrogenated nitrile rubber is 100,000-1,000,000. Please refer to FIG. 5, in the specific example, the rubber seal 25 is a sealing ring. It can be understood that the electrode terminal 21a is arranged on the outer side of the end cover 21. The hydrogenated nitrile rubber (HNBR) is a highly saturated elastomer material prepared by selectively hydrogenating the butadiene carbon-carbon double bond in the nitrile rubber (NBR). The HNBR has excellent heat resistance, low temperature resistance, ozone resistance, chemical resistance and mechanical strength while maintaining the oil resistance of the NBR. The HNBR has good mechanical properties and insulation properties, which can meet the corresponding performance requirements of battery sealing such as lithium ion battery.

[0082] Therefore, the rubber seal applied to the battery cell of the present application comprises hydrogenated nitrile rubber (HNBR) with a specific weight average molecular weight, and the hydrogenated nitrile rubber (HNBR) is in a solid state. The rubber seal prepared by using the hydrogenated nitrile rubber with the specific weight average molecular weight has good low temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance, so as to provide good sealing performance, thereby improving the service life of the battery and the battery cell.

[0083] Compared with the solid hydrogenated nitrile rubber, the liquid hydrogenated nitrile rubber has high price, and the strength and flex resistance of the hydrogenated nitrile rubber are poor, so that the tensile strength of the prepared sealing material is low, and the electrolyte swelling resistance and compression resistance are poor, which is difficult to meet the use requirements of the sealing material.

[0084] The higher the molecular weight of the hydrogenated nitrile rubber, the poorer the flowability, and the more difficult the processing. It is difficult to produce rubber with a molecular weight greater than 1,000,000, and the equipment requirements are also relatively harsh; in addition, the hydrogenation efficiency is slow and the cost is also high. Therefore, the weight average molecular weight of the hydrogenated nitrile rubber is controlled to be 100,000-1,000,000.

[0085] In some embodiments, the raw materials for preparing the rubber seal 25 comprise the above-mentioned hydrogenated nitrile rubber and vulcanizing agent, and optionally at least one of reinforcing filler, insulating filler, processing aid, vulcanization activator and vulcanization aid, and the weight average molecular weight of the hydrogenated nitrile rubber is 100,000-1,000,000.

[0086] Further, the raw materials for preparing the rubber seal 25 comprise the above-mentioned hydrogenated nitrile rubber, reinforcing filler, insulating filler, processing aid, vulcanizing agent, vulcanization activator and vulcanization aid, and the weight average molecular weight of the hydrogenated nitrile rubber is 100,000-1,000,000.

[0087] The rubber seal adopts hydrogenated nitrile rubber (HNBR) with a specific weight average molecular weight and is combined with reinforcing fillers, insulating fillers, processing aids, vulcanizing agents, vulcanizing activators and vulcanizing aids. Appropriately increasing the weight average molecular weight of HNBR can improve the physical and mechanical properties of the rubber, such as tensile strength and wear resistance, and the rubber seal has good heat resistance and aging resistance. However, HNBR with a high weight average molecular weight usually has a large viscosity, and higher energy is required to slow down the vulcanization speed during processing, which can adversely affect the performance of the vulcanized rubber seal. Therefore, by using the above preparation raw materials and controlling the weight average molecular weight within the above range, the processing performance of the HNBR rubber product can be improved, and the rubber seal prepared has good low temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance. In addition, the rubber seal also has good mechanical properties, high temperature resistance and compression resistance, thereby improving the service life of the rubber seal, the battery and the battery cell.

[0088] In some embodiments, the above preparation raw materials include 100 parts of hydrogenated nitrile rubber, 30-70 parts of reinforcing fillers, 10-30 parts of insulating fillers, 5-15 parts of processing aids, 3-10 parts of vulcanizing agents, 5-15 parts of vulcanizing activators and 0.5-4 parts of vulcanizing aids. The weight average molecular weight of the hydrogenated nitrile rubber is 100-1,000,000. Controlling the above preparation raw materials within the above range can improve the processing performance of the HNBR rubber product, and the rubber seal prepared has further improved elongation at break under the conditions of good low temperature resistance, insulation performance, electrolyte swelling resistance and compression resistance, thereby improving the service life of the rubber seal, the battery and the battery cell.

[0089] For example, the weight average molecular weight of the hydrogenated nitrile rubber can be 100,000, 150,000, 200,000, 220,000, 250,000, 270,000, 280,000, 300,000, 330,000, 350,000, 370,000, 400,000, 430,000, 450,000, 500,000, 550,000, 600,000, 650,000, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000 or 1,000,000.

[0090] In some embodiments of the present application, the weight average molecular weight of the hydrogenated nitrile rubber is 100-700,000, or 200-600,000, or 200-450,000, or within a range formed by any two of the above values as end values, and the like below.

[0091] The weight average molecular weight of the hydrogenated nitrile rubber within the range can make the rubber seal prepared have good low temperature resistance and insulation performance, and further improve the elongation at break and chemical resistance, especially electrolyte swelling resistance, thereby improving the service life of the battery and the battery cell.

[0092] In some embodiments of the present application, the hydrogenated nitrile rubber has an acrylonitrile content of 15wt% to 45wt%, for example, the hydrogenated nitrile rubber can have an acrylonitrile content of 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%. The higher the acrylonitrile content of the hydrogenated nitrile rubber, the higher the tensile strength, heat resistance, oil resistance, air tightness, hardness, but the lower the low temperature resistance, so further controlling the acrylonitrile content of the hydrogenated nitrile rubber in the above range based on the above raw material ratio can make the rubber sealing piece have better low temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance. Understandably, the acrylonitrile content of the hydrogenated nitrile rubber refers to the content of acrylonitrile units in the hydrogenated nitrile rubber.

[0093] In some embodiments of the present application, the hydrogenated nitrile rubber has a hydrogenation degree of ≥80%, or ≥90%. The hydrogenated nitrile rubber having a hydrogenation degree in the range can have better heat resistance, low temperature resistance, ozone resistance, chemical resistance and mechanical strength. For example, the hydrogenation degree of the hydrogenated nitrile rubber can be 80%, 85%, 90%, 95%, 99%, 100%.

[0094] For example, in the above raw materials, the hydrogenated nitrile rubber is 100 parts, and the reinforcing filler can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts. Further, the reinforcing filler includes at least one of carbon black, white carbon black, calcium carbonate, talc powder, mica powder and montmorillonite.

[0095] In a specific example, the reinforcing filler can be carbon black.

[0096] In another specific example, the reinforcing filler includes carbon black and calcium carbonate, or includes carbon black and white carbon black; further, the mass ratio of carbon black and calcium carbonate or the mass ratio of carbon black and white carbon black is (2-6):1, for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1. The addition of white carbon black can improve the insulation performance and elongation at break, so that the rubber sealing piece prepared has higher volume resistivity and elongation at break, and can provide better insulation performance and longer service life.

[0097] For example, in the above raw materials, the hydrogenated nitrile rubber is 100 parts, and the insulating filler can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts. Further, the insulating filler includes at least one of barium sulfate and kaolin.

[0098] In a specific example, the insulating filler can be kaolin or barium sulfate.

[0099] In another specific example, the insulating filler comprises kaolin and barium sulfate; further, the mass ratio of the kaolin and the barium sulfate is 1:(0.8-1.2), which may, for example, be 1:0.8, 1:0.9, 1:1, 1:1.1, or 1:1.2. The use of the compounded insulating filler can improve the insulating performance of the rubber seal.

[0100] For example, in the above preparation raw materials, the hydrogenated nitrile rubber is 100 parts, and the processing aid may, for example, be 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 13 parts, or 15 parts. Further, the processing aid comprises at least one of a fatty acid derivative and an organic acid ester compound.

[0101] Further, the fatty acid derivative comprises at least one of stearic acid, zinc stearate, magnesium stearate, calcium stearate, potassium stearate, and sodium stearate. The fatty acid derivative can act as a lubricant and a plasticizer.

[0102] Further, the organic acid ester compound comprises at least one of trioctyl trimellitate, diisononyl phthalate, and di(2-ethyl)hexyl phthalate. The fatty acid derivative can act as a plasticizer.

[0103] In some embodiments, the above preparation raw materials may, for example, further comprise liquid hydrogenated nitrile rubber, which can act as a plasticizer. It should be noted that the weight average molecular weight of the liquid hydrogenated nitrile rubber is <100,000.

[0104] In a specific example, the processing aid comprises an organic acid ester compound and a fatty acid derivative, which are compounded to further improve the processing performance, and thus the mechanical performance of the prepared seal; further, the processing aid comprises trioctyl trimellitate and stearic acid. Further, the mass ratio of the organic acid ester compound and the fatty acid derivative is (4-8):1; further, the mass ratio may, for example, be 4:1, 5:1, 6:1, 7:1, or 8:1.

[0105] For example, in the above preparation raw materials, the hydrogenated nitrile rubber is 100 parts, and the vulcanizing agent may, for example, be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts. Further, the vulcanizing agent comprises a peroxide vulcanizing agent, a sulfur vulcanizing agent, and a metal oxide vulcanizing agent.

[0106] Further, the peroxide vulcanizing agent comprises at least one of dicumyl peroxide (DCP), di(tert-butylperoxy isopropyl) benzene (BIPB), and 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane.

[0107] As an example, in the above preparation raw materials, the hydrogenated nitrile rubber is 100 parts by weight, and the vulcanization activator can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts. Further, the vulcanization activator includes metal oxides. Further, the metal oxides include at least one of zinc oxide and magnesium oxide. These metal oxides in the vulcanization activator can promote the chemical reaction between the rubber molecular chain and the vulcanizing agent by forming a complex, help to generate crosslinking bonds, and form a stable network structure. Not only can it increase the crosslinking density of the rubber to a certain extent, but also can improve the processing performance of the rubber and improve the dimensional stability of the rubber product.

[0108] Further, the metal oxides in the vulcanization activator include both zinc oxide and magnesium oxide; further, the mass ratio of zinc oxide and magnesium oxide is (1-2):1, as an example, it can be 1:1, 1.1:1, 8:7, 1.2:1, 1.3:1, 4:3, 1.4:1, 1.5:1, 1.6:1, 5:3, 1.7:1, 1.8:1, 2:1.

[0109] As an example, in the above preparation raw materials, the hydrogenated nitrile rubber is 100 parts by weight, and the vulcanization activator can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts. Further, the vulcanization activator includes metal oxides. Further, the metal oxides include at least one of zinc oxide and magnesium oxide. These metal oxides in the vulcanization activator can promote the chemical reaction between the rubber molecular chain and the vulcanizing agent by forming a complex, help to generate crosslinking bonds, and form a stable network structure. Not only can it increase the crosslinking density of the rubber to a certain extent, but also can improve the processing performance of the rubber and improve the dimensional stability of the rubber product.

[0110] In some embodiments of the present application, in the above preparation raw materials, the hydrogenated nitrile rubber is 100 parts by weight, the reinforcing filler is 40-60 parts, the insulating filler is 10-15 parts, the processing aid is 8-12 parts, the vulcanizing agent is 5-8 parts, the vulcanization activator is 7-10 parts, and the vulcanization aid is 2-3 parts. Controlling the components of the above preparation raw materials within this range can further improve the electrolyte swelling resistance, compression resistance, tensile strength and elongation at break of the hydrogenated nitrile rubber sealing material, and further improve the service life of the battery and the battery cell, while the low temperature resistance and insulation performance of the rubber sealing piece are relatively good.

[0111] The rubber sealing piece prepared from the above preparation raw materials has good low temperature resistance, insulation performance and chemical resistance, especially electrolyte swelling resistance, in addition to good mechanical properties, high temperature resistance and compression resistance.

[0112] The application also provides a raw material composition for preparing the rubber seal, which comprises hydrogenated nitrile rubber and vulcanizing agent. Further, reinforcing filler, insulating filler, processing aid, vulcanization activator and vulcanization aid are also included. The weight fractions of the above raw materials are as described above, which will not be repeated here.

[0113] The method for preparing the rubber seal comprises the following steps S10-S20:

[0114] S10, mixing the raw materials to obtain a rubber compound.

[0115] In some embodiments, step S10 comprises the following steps S11-S12.

[0116] S11, plasticizing the hydrogenated nitrile rubber and then mixing the reinforcing filler, insulating filler, processing aid and vulcanization activator.

[0117] Further, the temperature for mixing in S11 is 50-100°C, and the time is 5-10 minutes. As an example, the temperature for mixing in S11 can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, and the time can be 5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes.

[0118] S12, then sequentially adding the vulcanizing agent and vulcanization aid for mixing to obtain a rubber compound containing hydrogenated nitrile rubber, and cooling.

[0119] Further, the temperature for mixing in S12 is 50-100°C, and the time is 5-10 minutes. As an example, the temperature for mixing in S12 can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, and the time can be 5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes.

[0120] Further, the cooling step comprises placing at 23±2°C for 8-24 hours.

[0121] S20, vulcanizing the rubber compound to obtain a rubber seal.

[0122] In some embodiments, the temperature for vulcanizing in S20 is 140-200°C; as an example, the temperature can be 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, further can be 140-180°C, or a range formed by any two of the above-mentioned points as end values.

[0123] In some embodiments, the pressure of the vulcanization forming in S20 is 8-20 MPa; for example, the pressure is 8 MPa, 9 MPa, 10 MPa, 12 MPa, 14 MPa, 15 MPa, 16 MPa, 18 MPa, or 20 MPa.

[0124] In some embodiments, the time of the vulcanization forming in S20 is 1*T90-3*T90; for example, the time is 1*T90, 1.5*T90, 2*T90, 2.5*T90, or 3*T90. Herein, T90 refers to the process curing time of the vulcanization system, specifically, the time required for the torque to reach 90% of the maximum torque from the start of heating, which can be obtained from the vulcanization curve obtained by a vulcanization instrument.

[0125] Further, the temperature of the vulcanization forming is 160-180℃, the pressure is 10-15 MPa, and the time is (1.5-2.5)*T90. 90

[0126] In some embodiments, the rubber sealing member can include, but is not limited to, a sealing ring, a sealing gasket, etc. The above vulcanization forming can be performed in different molds according to different shapes of the rubber sealing member.

[0127] The mass change rate of the above rubber sealing member is <40% and the volume expansion rate is <40% when immersed in a dimethyl carbonate solvent at 70℃. In some embodiments of the present application, the mass change rate of the above rubber sealing member is ≤30% and the volume expansion rate is ≤30% when immersed in a dimethyl carbonate solvent at 70℃.

[0128] The compression permanent set of the above rubber sealing member is <30%. In some embodiments of the present application, the compression permanent set of the above rubber sealing member is ≤20%. Herein, the compression permanent set is tested according to the national standard GB / T 7759.1 after compression at 120℃ for 9 days.

[0129] The volume resistivity of the above rubber sealing member is >1*10 10 Ω·cm, which is tested at a test voltage of 500V according to the national standard GBT 31838.2-2019.

[0130] The tensile strength of the above rubber sealing member is ≥14.0 MPa and the elongation at break is ≥130%. In some embodiments of the present application, the tensile strength of the above rubber sealing member is ≥15.0 MPa, further, the tensile strength is ≥18.0 MPa and the elongation at break is ≥150%. The tensile strength of the above rubber sealing member is ≥15.0 MPa and the elongation at break is ≥150% to meet the use requirements of the battery cell well; further, the tensile strength is ≥18.0 MPa and the elongation at break is ≥150% to better meet the use requirements of the battery cell.​

[0131] In some embodiments of the present application, the low-temperature brittleness temperature (i.e., ductile-brittle transition temperature) of the rubber seal described above can be as low as -52.8°C, with excellent low-temperature resistance, while also having good high-temperature resistance, and can be used for a long time at -40°C to 120°C. Further, it can be used for a long time at -50°C to 120°C. In some specific examples, the low-temperature brittleness temperature of the rubber seal described above is -50°C to -45°C.

[0132] The shape of the battery cell 20 is not particularly limited in the present application, and can be a cylinder, a flat body, a cuboid, or any other shape. For example, the battery cell 20 shown in FIG. 3 is a cuboid structure as an example. Referring to FIG. 3, the shell 22 can include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. An opening of the shell 22 is in communication with the receiving cavity, and the end cover 21 can be provided on the opening to close the receiving cavity. The cell assembly 23 is packaged in the receiving cavity.

[0133] The number of cell assemblies 23 contained in the battery cell 20 can be one or more, which can be selected by a person skilled in the art according to specific actual needs.

[0134] In some embodiments, the cell assembly 23 includes a positive electrode sheet, a separator film, and a negative electrode sheet arranged in a stack, and the positive electrode sheet, the separator film, and the negative electrode sheet can form the cell assembly 23 through a winding process or a stacking process. The battery cell 20 described above further includes an electrolyte, which is provided in the shell 22, and the cell assembly 23 is soaked in the electrolyte.

[0135] Positive electrode sheet

[0136] The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, and the positive electrode film layer includes a positive electrode active material.

[0137] As a non-limiting example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material layer is provided on any one or both of the two opposite surfaces of the positive electrode current collector.

[0138] In some embodiments, the positive current collector can employ a metal foil or a composite current collector. For example, as a metal foil, an aluminum foil can be employed. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be obtained by forming a metal material on a polymer material base material. Non-limiting examples of the metal material in the positive current collector can include one or more of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like. Non-limiting examples of the polymer material base material in the positive current collector can include one or more of a polypropylene (PP) base material, a polyethylene terephthalate (PET) base material, a polybutylene terephthalate (PBT) base material, a polystyrene (PS) base material, a polyethylene (PE) base material, and the like.

[0139] In some embodiments, the positive active material can employ a positive active material for a battery known in the art. As non-limiting examples, the positive active material can include one or more of a lithium-containing phosphate of an olivine structure, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive active material for a battery can also be used. These positive active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium transition metal oxide can include, but are not limited to, one or more of a lithium cobalt oxide (e.g., LiCoO2), a lithium nickel oxide, a lithium manganese oxide, a lithium nickel cobalt oxide, a lithium manganese cobalt oxide, a lithium nickel manganese oxide, a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide, and a modified compound thereof. Non-limiting examples of the lithium-containing phosphate of an olivine structure can include, but are not limited to, one or more of lithium iron phosphate, a composite of lithium iron phosphate and carbon, lithium manganese phosphate, a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite of lithium manganese iron phosphate and carbon.

[0140] Non-limiting examples of the lithium cobalt oxide can include LiCoO2; non-limiting examples of the lithium nickel oxide can include LiNiO2; non-limiting examples of the lithium manganese oxide can include LiMnO2, LiMn2O4, and the like; non-limiting examples of the lithium nickel cobalt manganese oxide can include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also referred to simply as NCM 211 ), LiNi 0.6Co 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 ), and the like. Non-limiting examples of lithium nickel cobalt aluminum oxides can include LiNi 0.8 Co 0.15 Al 0.05 O2.

[0141] It can be appreciated that the battery will be accompanied by lithium (Li) deintercalation and consumption during charging and discharging, and the content of Li in the positive active material is different when the battery is discharged to different states. In the enumeration of the positive active material in this application, the content of Li is the initial state of the material unless otherwise stated. When the positive active material is applied to the positive electrode sheet in the battery system, the content of Li in the positive active material contained in the sheet will usually change after charging and discharging cycles. Among them, the content of Li can be quantified by molar content, but is not limited thereto. As for "the content of Li is the initial state of the material", the initial state of the material refers to the state before being put into the positive electrode slurry. It can be appreciated that new materials obtained by proper modification on the basis of the listed positive active materials are also within the scope of positive active materials, and the foregoing proper modification refers to acceptable modification methods for positive active materials, non-limiting examples of which include coating modification.

[0142] In the enumeration of the positive active material in this application, the content of oxygen (O) is only the theoretical state value, and the release of oxygen from the lattice will cause the molar content of oxygen to change, and the actual content of O will fluctuate. Among them, the content of O can be quantified by molar content, but is not limited thereto.

[0143] In some embodiments, the positive active material layer also optionally includes a binder. As non-limiting examples, the binder can include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluorine-containing acrylate resin.

[0144] In some embodiments, the positive active material layer also optionally includes a conductive agent. As non-limiting examples, the conductive agent can include one or more of super P carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0145] In some embodiments, the positive electrode sheet can be prepared by dispersing the components described above for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder, and any other components, in a solvent to form a positive electrode slurry; coating the positive electrode slurry on at least one side surface of the positive electrode current collector; and drying, cold-pressing, or the like to obtain the positive electrode sheet. The solvent can be selected from, but is not limited to, any of the aforementioned embodiments, such as N-methylpyrrolidone (NMP). The positive electrode slurry can be coated on a single surface of the positive electrode current collector, or on both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40 wt% to 80 wt%.

[0146] Negative electrode sheet

[0147] The negative electrode sheet includes a negative electrode current collector. Further, the negative electrode sheet can also include a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material.

[0148] As a non-limiting example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material layer is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0149] In some embodiments, the negative electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, a copper foil can be used. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be obtained by forming a metal material on a polymer material base layer. Non-limiting examples of the metal material in the negative electrode current collector can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, and the like. Non-limiting examples of the polymer material base layer in the negative electrode current collector can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), and the like.

[0150] In some embodiments, the negative electrode active material can be a negative electrode active material known in the art for use in a battery. As a non-limiting example, the negative electrode active material can include one or more of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like. The silicon-based material can include one or more of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can include one or more of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery can also be used. The negative electrode active material can be used alone or in combination of two or more.

[0151] In some embodiments, the negative active material layer can optionally further include a binder. The binder can include one or more of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0152] In some embodiments, the negative active material layer can optionally further include a conductive agent. The conductive agent can include one or more of super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0153] In some embodiments, the negative active material layer can optionally further include other auxiliary agents, such as a thickening agent (e.g., sodium carboxymethyl cellulose (CMC-Na)), and the like.

[0154] In some embodiments, the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as the negative active material, the conductive agent, the binder, and any other components, in a solvent (a non-limiting example of the solvent is deionized water) to form a negative electrode slurry; coating the negative electrode slurry on at least one side surface of the negative current collector, and after processes such as drying, cold pressing, and the like, the negative electrode sheet can be obtained. The surface of the negative current collector coated with the negative electrode slurry can be on a single surface of the negative current collector, or on both surfaces of the negative current collector. The solid content of the negative electrode slurry can be 40 wt% to 60 wt%.

[0155] Electrolyte

[0156] The electrolyte functions to conduct ions between the positive electrode sheet and the negative electrode sheet. The above-mentioned cell assembly 23 is impregnated in the electrolyte. The electrolyte includes an electrolyte salt and a solvent. Since the solvent in the electrolyte is generally an organic solvent, and the sealing member is also an organic material, the sealing member is prone to swelling in the electrolyte, which in turn affects the sealing performance of the sealing member. As described above, the HNBR sealing material absorbs the electrolyte in the battery and swells after being used for a period of time, thus leading to a decrease in the service life and sealing performance of the sealing material.

[0157] In some embodiments, the solvent includes at least one of an ether solvent, an ester solvent, and a sulfone solvent.

[0158] As an example, the ether solvent can include at least one of dimethoxyethane (DME), diethylene glycol dimethyl ether (DEGDME), triethylene glycol dimethyl ether (TRGDME), tetraethylene glycol dimethyl ether (TEGDME), and 1,3-dioxolane (DOL).

[0159] As an example, the ester solvent can include at least one of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl carbonate (VC), fluoroethylene carbonate (FEC), methyl ethyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), γ-butyrolactone (BL), 1,3-propane sultone (1,3-PS), methyl propionate (MP), methyl butyrate (MB), ethyl acetate (EA), ethyl propionate (EP), propyl propionate (PP), and ethyl butyrate (EB).

[0160] As an example, the sulfone-based solvent includes dimethyl sulfoxide (DMSO).

[0161] In some embodiments, the electrolyte salt includes at least one of a sodium salt, a lithium salt, and a potassium salt.

[0162] As an example, the sodium salt in the electrolyte salt can be selected from one or more of sodium perchlorate (NaClO4), sodium tetrafluoroborate (NaBF4), sodium hexafluorophosphate (NaPF6), sodium hexafluoroarsenate (NaAsF6), sodium trifluoroacetate (CF3COONa), sodium tetraphenylborate (NaB(C6H5)4), sodium trifluoromethylsulfonate (NaSO3CF3), sodium bis(fluorosulfonyl)imide (Na[(FSO2)2N]), or sodium bis(trifluoromethylsulfonyl)imide (Na[(CF3SO2)2N]).

[0163] As an example, the lithium salt in the electrolyte salt can be selected from one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium trifluoromethylsulfonate (LiTFS), lithium difluoro(oxalato)borate (LiDFOB), lithium difluoro(oxalato)phosphate (LiPO2F2), lithium difluoro(oxalato)phosphate (LiDFOP), and lithium tetrafluoro(oxalato)phosphate (LiTFOP).

[0164] In some embodiments, the electrolyte solution can also optionally include an additive. For example, the additive can include a negative electrode film-forming additive, a positive electrode film-forming additive, and can also include an additive capable of improving certain properties of the battery, such as an additive for improving overcharge performance of the battery, an additive for improving high-temperature or low-temperature performance of the battery, etc.

[0165] Separator film

[0166] In some embodiments, a separator film is also included in the battery. The separator film is disposed between the positive electrode sheet and the negative electrode sheet, and functions to separate.

[0167] In some embodiments, the material of the isolation film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The isolation film can be a single-layer film or a multi-layer composite film. When the isolation film is a multi-layer composite film, the materials of the layers can be the same or different.

[0168] When the isolation film is a multi-layer composite film, the materials of the layers can be the same or different, and are not particularly limited.

[0169] In some embodiments, the thickness of the isolation film is 6 μm to 40 μm, and can be selected from 12 μm to 20 μm.

[0170] Another embodiment of the present application further provides a battery comprising one or more of the above-mentioned battery cells.

[0171] The battery cell is the smallest unit constituting the battery, and a plurality of battery cells can be connected in series or in parallel or in a mixed manner. That is, one battery can comprise one or more battery cells, and the plurality of battery cells can be connected in series or in parallel or in a mixed manner. The mixed manner means that the plurality of battery cells are connected in series and in parallel.

[0172] After the plurality of battery cells are connected to each other and arranged in a certain order, they can be directly accommodated in the box to form the battery. Alternatively, the plurality of battery cells can be first assembled into a battery module, and then the plurality of battery modules are connected to each other to form a whole, and finally the whole of the battery module is accommodated in the box to form the battery.

[0173] In some embodiments, the above-mentioned battery can be, but is not limited to, a lithium ion battery, a sodium ion battery.

[0174] In addition, an embodiment of the present application further provides an electric device, which comprises the above-mentioned battery provided by the present application. The battery can be used as a power supply of the electric device, or as an energy storage unit of the electric device. The electric device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. The mobile device can be, for example, a mobile phone, a notebook computer, etc.; the electric vehicle can be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but is not limited thereto.

[0175] As the electric device, the battery cell, the battery pack or the battery module can be selected as the battery according to the use requirement.

[0176] Fig. 6 is an example of an electric device 2. The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the demand of the electric device for a high power and a high energy density of a battery, a battery pack or a battery module can be used as a power source.

[0177] An example of the device can be a mobile phone, a tablet, a notebook, etc. The device generally requires thinness, and a battery monomer can be used as a power source.

[0178] For the purpose, technical solutions and advantages of the present application to be more concise and clear, the present application is described by the following specific examples, but the present application is not limited to these examples. The examples described below are only good examples of the present application, which can be used to describe the present application, and should not be understood as limiting the scope of the present application. It should be noted that any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

[0179] In order to better illustrate the present application, the content of the present application is further described below in combination with examples. The following are specific examples.

[0180] Reagent information:

[0181] The weight average molecular weight of hydrogenated nitrile rubber 1 (HNBR1) is 30±3 million, the acrylonitrile content is 34%, and the hydrogenation degree is 99%.

[0182] The weight average molecular weight of hydrogenated nitrile rubber 2 (HNBR2) is 25±3 million, the acrylonitrile content is 43%, and the hydrogenation degree is 99%.

[0183] The weight average molecular weight of hydrogenated nitrile rubber 3 (HNBR3) is 40±3 million, the acrylonitrile content is 40%, and the hydrogenation degree is 99%.

[0184] The weight average molecular weight of hydrogenated nitrile rubber 4 (HNBR4) is 50±10 million, the acrylonitrile content is 21%, and the hydrogenation degree is 95%.

[0185] The weight average molecular weight of hydrogenated nitrile rubber 5 (HNBR5) is 100±10 million, the acrylonitrile content is 17%, and the hydrogenation degree is 99%.

[0186] Example 1

[0187] The raw materials for preparing a rubber seal include the components shown in Table 1 by weight parts.

[0188] The specific preparation method in this example is as follows:

[0189] (1) After the internal mixer was started, the raw rubber of hydrogenated nitrile rubber (HNBR1) was added for plasticizing work, and then the processing aids (trioctyl trimellitate and stearic acid), vulcanization activators (ZnO and MgO), insulating filler (kaolin), reinforcing filler (carbon black) were added together, and the rubber was blended at 70°C for 6 minutes and 30 seconds to discharge the rubber.

[0190] (2) After the internal mixer was started again, the rubber compound obtained in (1) was added, and then the vulcanizing agent (DCP) and vulcanization aid (TAIC) were added, and the rubber was blended at 70°C for 7 minutes to discharge the rubber. The rubber compound was then rolled into a triangle package using an open mill for 10 times to obtain a rubber compound, which was cooled at room temperature for at least 24 hours.

[0191] (3) The rubber compound obtained in step (2) was vulcanized in a vulcanizing machine, with a vulcanization temperature of 180°C, a pressure of 10 MPa, and a vulcanization time of 2xT90, to obtain a rubber sealing member (sealing ring). T90 refers to the process vulcanization time of the vulcanization system, which is the time required for the torque to reach 90% of the maximum torque from the start of heating, which can be obtained from the vulcanization curve obtained by a vulcanization instrument.

[0192] The prepared rubber sealing ring was applied to a battery monomer. The battery monomer of the present embodiment, as shown in Figure 1, includes a shell 22, an electrode assembly 23, and an end cover 21. The shell 22 has an opening 111, and the electrode assembly 23 is accommodated in the shell 22; the end cover 21 is sealingly arranged in the opening 111. Referring to Figures 3, 4 and 5, the battery monomer 20 further includes an electrode terminal 21a and a rubber sealing member 25. The electrode terminal 21a is arranged on the end cover 21 and is used to connect with the electrode assembly 23. The rubber sealing member 25 is sealingly arranged between the electrode terminal 21a and the end cover 21. The end cover 21 is provided with a mounting hole 231, and the electrode terminal 21a is arranged on the end cover 21 through the mounting hole 231 and connected with the electrode assembly 23 inside the shell 22. The battery monomer 20 further includes an electrolyte, which is arranged in the shell 22 and the electrode assembly 23 is soaked in the electrolyte. The composition of the electrolyte is that the electrolyte contains ethylene carbonate and methyl ethyl carbonate in a mass ratio of 3:7, and contains LiPF6 with a concentration of 1 mol / L.

[0193] Example 2

[0194] The raw materials for preparing a rubber sealing member include the components shown in Table 1 in parts by weight.

[0195] The specific preparation method in the present embodiment is as follows:

[0196] (1) After starting the internal mixer, the raw rubber of hydrogenated nitrile rubber (HNBR1) was added for plasticization, and then the processing aids (trioctyl trimellitate and stearic acid), vulcanization activators (ZnO and MgO), insulating filler (kaolin), reinforcing filler (carbon black) were added together, and the rubber was blended at 70°C for 6 minutes and 30 seconds to discharge the rubber.

[0197] (2) After starting the internal mixer again, the rubber compound obtained in (1) was added, and then the vulcanizing agent (BIPB) and vulcanization aid (TAIC) were added, and the rubber was blended at 70°C for 7 minutes to discharge the rubber. The rubber compound was rolled into a triangle package using an open mill for 10 times to obtain a rubber compound, which was placed at room temperature for at least 24 hours.

[0198] (3) The rubber compound obtained in step (2) was vulcanized in a vulcanizing machine, with a vulcanization temperature of 180°C, a pressure of 10 MPa, and a vulcanization time of 2xT90.

[0199] Examples 3-17

[0200] A preparation material for a rubber seal was prepared, including the components shown in Table 1 by weight. The preparation material was basically the same as that of Example 1, and the only difference was that at least one of the types and proportions of the components of the preparation material was different, as shown in Table 1.

[0201] Examples 18-21

[0202] The composition and proportion of the preparation material for a rubber seal were the same as those of Example 1, and the only difference was that the specific type of hydrogenated nitrile rubber in the preparation material was different (specifically, the weight average molecular weight, acrylonitrile content, and hydrogenation degree were different), as shown in Table 2.

[0203] Comparative Example 1

[0204] Comparative Example 1 was basically the same as Example 1, except that an equal amount of liquid hydrogenated nitrile rubber (weight average molecular weight of 8±1 million, acrylonitrile content of 34%, hydrogenation degree of 99%) was used instead of HNBR1 in Example 1.

[0205] Table 1

[0206] Table 2

[0207] The following are the performance test results and test methods of the seals prepared in the above examples and comparative examples, and the results are shown in Table 3.

[0208] Table 3

[0209] The sealing material prepared by Comparative Example 1 has a relatively low low-temperature brittleness temperature and good insulation performance, but has poor electrolyte swelling resistance, with a mass change rate > 40% and a volume expansion rate > 40% after immersion in dimethyl carbonate at 70°C for 3 days, and has a low tensile strength of 11.2 MPa (< 14 MPa), which is difficult to meet the use requirements. In addition, the sealing material prepared by Comparative Example 1 has a relatively large compression set of 32.8% (> 30%) under the condition of compression at 120°C for 9 days, is prone to deformation, and has a relatively short service life.

[0210] The sealing material prepared by the above examples is a hydrogenated nitrile rubber-based sealing material, with a low-temperature brittleness temperature of -47°C to -52.8°C, excellent low-temperature resistance, good insulation performance (volume resistivity of the material is 1 x 10 10 Ω·cm or more), and good electrolyte swelling resistance, with a mass change rate < 40% and a volume expansion rate < 40% after immersion in dimethyl carbonate at 70°C for 3 days. In addition, the tensile strength of the sealing material of the examples is ≥ 14.0 MPa, and the elongation at break is ≥ 130.2%, showing good mechanical properties; at the same time, the compression set is < 30% under the condition of compression at 120°C for 9 days, and is between 17.2% and 26.3%, showing good compression set resistance. Therefore, the sealing material provided by the examples of the present application can meet the sealing and insulation requirements of lithium ion batteries, and does not contain fluorine elements in the raw materials, avoiding the use of fluorine-containing compounds, and meeting the demand for non-fluorine-containing rubber sealing materials required by lithium ion batteries and other batteries.

[0211] As can be seen from Examples 1-17, the reinforcing fillers in Examples 14-15 are more or less, and the vulcanizing agents in Examples 16-17 are more or less, and the elongation at break of the hydrogenated nitrile rubber sealing material prepared thereby is relatively low; controlling the proportion of the raw materials within the range of Examples 1-13 can further improve the elongation at break of the hydrogenated nitrile rubber sealing material under the conditions of good low-temperature resistance, insulation performance, electrolyte swelling resistance, and compression resistance; specifically, the tensile strength is ≥ 15.0 MPa, the elongation at break is ≥ 140%, the mass change rate of electrolyte swelling resistance is ≤ 30%, the volume expansion rate is ≤ 30%, and the compression set is ≤ 25%.

[0212] Further, the proportion of the raw materials for preparation is controlled in the range of embodiments 1-4, 9-11, which can further improve the electrolyte swelling resistance, compression resistance, tensile strength and elongation at break of the sealing material of the hydrogenated nitrile rubber in the case of better low-temperature resistance and insulation performance; specifically, the mass change rate of the electrolyte swelling resistance is ≤27%, the volume expansion rate is ≤29%, the tensile strength is ≥18.0 MPa, the elongation at break is ≥150%, and the compression permanent set is ≤20%.

[0213] Further, compared with embodiment 1, embodiment 9 uses a compounded reinforcing filler of carbon black and calcium carbonate, and other performances are equivalent to those of embodiment 1, and the elongation at break is slightly improved. Embodiment 12 uses a compounded reinforcing filler of carbon black and white carbon black, and since the addition of white carbon black can improve the insulation performance and elongation at break, it has a higher volume resistivity and elongation at break. Embodiment 10 uses a compounded insulation filler of kaolin and barium sulfate, and also has a higher volume resistivity.

[0214] As can be seen from the comparison of embodiments 1, 18-21, controlling the weight average molecular weight of the hydrogenated nitrile rubber in the raw materials for preparation in the range of 200-450 thousand within 200-1000 thousand can further improve the elongation at break and electrolyte swelling resistance of the sealing material of the hydrogenated nitrile rubber; specifically, the mass change rate of the electrolyte swelling resistance is ≤27%, the volume expansion rate is ≤30%, and the elongation at break is ≥150%.

[0215] The above test methods are as follows.

[0216] (1) Low-temperature brittleness test: the test is carried out according to the provisions of GB / T 1682-2014, and the vulcanized sealing samples of each embodiment are used. The sample is loaded into a lifting holder, frozen in a refrigerated medium to a specified time, the lifting holder is raised, the sample is impacted with an impactor within a specified time, the sample is taken out, and after resting for at least 30 seconds, the sample is bent to 180° in the impact direction, and whether there is damage is observed. Through repeated tests, the lowest temperature at which the sample is not damaged and the highest temperature at which two or more samples in the previous group are damaged are determined, and when the difference between the two results is not more than 1℃, the highest temperature at which the sample is damaged is the brittleness temperature.

[0217] Parameter result acquisition standard: if none of the samples in a group of samples is damaged at a certain temperature, the test result is that the sample is not damaged at that temperature. If two or more samples in a group of samples are completely damaged, the test result is that the sample is damaged. If only one sample in a group of samples is damaged, three new intact samples are tested again, and if all three samples are not damaged, the test result is not damaged, otherwise the test result is damaged.

[0218] (2) Volume resistivity:

[0219] The test is carried out according to GBT 31838.2-2019, and the test voltage is specified as 10V, 100V, 500V, 1000V or 10000V. The volume resistivity of the present application selects 500V as the measurement voltage.

[0220] The vulcanized rubber sample for measuring the rubber resistivity is circular, with a diameter of ≥100mm and a thickness of 1.0mm±0.5mm.

[0221] The measurement of rubber resistivity generally requires the use of electrical testing instruments or meters, such as ohmmeters, conductivity meters, etc.

[0222] Method for measuring the volume resistivity of rubber: take the rubber sample to be tested (three as a group), measure the thickness of the sample, put the sample into the resistance measuring instrument, input the thickness of the sample, read the resistivity value after the test is completed and record it.

[0223] (3) Electrolyte solution swelling resistance:

[0224] The electrolyte is generally prepared by mixing high-purity organic solvents, electrolyte lithium salts (lithium hexafluorophosphate, LiPF6), necessary additives, etc. in a certain proportion under certain conditions. The solvents in the electrolyte are commonly propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, etc.

[0225] Currently, the reagent used to simulate the swelling behavior of the electrolyte is dimethyl carbonate.

[0226] Cut the prepared rubber sealing piece to obtain 25mm*25mm*2mm samples (three), and measure their mass in air and mass in water before swelling. Put the samples into separate reaction kettles containing 25mL of dimethyl carbonate solvent, one piece in each kettle, and place them in a 70℃ oven for 72h. After cooling for 30min to room temperature, measure the mass in air and mass in water after swelling.

[0227] Method for calculating the mass change rate:

[0228] Method for calculating the volume expansion rate:

[0229] In the formula:

[0230] m 11 - mass in air before swelling;

[0231] m 12 - mass in air after swelling;

[0232] m 21 - mass in water before swelling;

[0233] m 22 — Mass in water after swelling.

[0234] (4) Tensile strength and elongation at break:

[0235] The test was carried out according to GB / T 5720-2008, and the sealing material was made into dumbbell-shaped samples using the same process conditions as in each example, and then tested on a tensile testing machine. Type 2 dumbbell-shaped tensile samples were used, with a thickness of 2 ± 0.2 mm and a tensile speed of 500 ± 50 mm / min.

[0236] Tensile strength is the maximum tensile stress during the tensile process of the sample to break, and elongation at break is the percentage elongation at the time of sample breakage, which respectively reflects the tensile strength and plastic deformation capacity of the material.

[0237] Test method: The thickness of the tensile sample was measured using a thickness gauge (at least three for a group), and the median of the three values was recorded and input. The sample was symmetrically clamped on the tensile testing machine, and the testing machine was started for tensile testing. A constant tensile speed was applied to the sample, and the sample was continuously stretched until the material broke. After the test was completed, the tensile strength and elongation at break were read and recorded.

[0238] (5) Compression set:

[0239] The degree of compression set is used to determine the sealing performance of the elastomer seal.

[0240] The test was carried out according to GB / T 7759.1, and the sealing material was made into B-type samples using the same process conditions as in each example, and the compression permanent deformation rate at 120°C for 9 days @ 15% was tested. The B-type sample is a cylindrical shape with a diameter of 13 mm ± 5 mm and a height of 6. mm 3 ± 0.3 mm. When the compression rate is 15%, the stopper height is 5.3 mm ~ 5.4 mm.

[0241] Compression permanent deformation rate is a measure of the proportion of the original size of a material that is reduced when it is subjected to compression. In the compression permanent deformation test of rubber materials, it defines the degree to which the sample should be compressed during the test. The smaller the compression permanent deformation rate, the better the compression resistance, i.e. the better the sealing performance of the elastomer seal.

[0242] Test method: The thickness of the sample block was measured using a thickness gauge, and the sample block was placed in the compression device. The B-type 15% stopper was selected, and after compression, it was placed in a 120°C constant temperature oven for 9 days. After taking it out, the sample was loosened and placed on a wooden board for 30 min, and then the thickness of the compressed sample was measured using a thickness gauge.

[0243] The compression permanent deformation calculation formula is as follows:

[0244] In the formula:

[0245] h0 - original height of the sample, mm;

[0246] hi - height after compression recovery, mm;

[0247] h s - height of the limiter, mm.

[0248] Each technical feature of the above-described embodiments can be combined arbitrarily, and to make the description simple, each technical feature in the above-described embodiments is not described in all possible combinations, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the description.

[0249] The above-described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A battery cell, comprising: a housing having an opening; a cell assembly housed in the housing; a terminal cover sealingly disposed in the opening; an electrode terminal disposed on the terminal cover and configured to connect with the cell assembly; and a rubber seal sealingly disposed between the electrode terminal and the terminal cover, wherein the rubber seal comprises a hydrogenated nitrile rubber having a weight average molecular weight of 100,000 to 1,000,000. The hydrogenated nitrile rubber has a weight average molecular weight of 200,000 to 450,000. At least one of the following conditions is satisfied: (1) the hydrogenated nitrile rubber has an acrylonitrile content of 15 wt% to 45 wt%; and (2) the hydrogenated nitrile rubber has a hydrogenation degree of ≥ 80%. The raw materials for preparing the rubber seal include the hydrogenated nitrile rubber, a reinforcing filler, an insulating filler, a processing aid, a vulcanizing agent, a vulcanizing activator, and a vulcanizing co-agent. In the raw materials, the hydrogenated nitrile rubber is 100 parts, the reinforcing filler is 30 to 70 parts, the insulating filler is 10 to 30 parts, the processing aid is 5 to 15 parts, the vulcanizing agent is 3 to 10 parts, the vulcanizing activator is 5 to 15 parts, and the vulcanizing co-agent is 0.5 to 4 parts. In the raw materials, the hydrogenated nitrile rubber is 100 parts, the reinforcing filler is 40 to 60 parts, the insulating filler is 10 to 15 parts, the processing aid is 8 to 12 parts, the vulcanizing agent is 5 to 8 parts, the vulcanizing activator is 7 to 10 parts, and the vulcanizing co-agent is 2 to 3 parts. The reinforcing filler includes at least one of carbon black, white carbon black, calcium carbonate, talc, mica powder, and montmorillonite.

2. The battery cell of claim 1, wherein, The insulating filler includes at least one of barium sulfate and kaolin.

3. The battery cell of any one of claims 1 to 2, wherein, The processing aid includes at least one of a fatty acid derivative and an organic acid ester compound. At least one of the following conditions is satisfied: (1) the fatty acid derivative includes at least one of stearic acid, zinc stearate, magnesium stearate, calcium stearate, potassium stearate, and sodium stearate; and (2) the organic acid ester compound includes at least one of trioctyl trimellitate, diisononyl phthalate, and di(2-ethyl)hexyl phthalate. At least one of the following conditions is satisfied: (1) the vulcanizing activator includes a metal oxide; (2) the vulcanizing agent includes at least one of a peroxide vulcanizing agent, a sulfur vulcanizing agent, and a metal oxide vulcanizing agent; and (3) the vulcanizing co-agent includes at least one of zinc dimethyl acrylate, triallyl cyanurate, triallyl isocyanurate, and bismaleimide.

4. The battery cell of any one of claims 1 to 3, wherein, At least one of the following conditions is satisfied: (1) the metal oxide includes at least one of zinc oxide and magnesium oxide; and (2) the peroxide vulcanizing agent includes at least one of dicumyl peroxide, di(tert-butylperoxy isopropyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

5. The battery cell of claim 4, wherein, The preparation of the rubber seal includes the following steps: mixing the raw materials to obtain a rubber compound; and vulcanizing the rubber compound to obtain the rubber seal.

6. The battery cell of claim 5, wherein, ​ 7. The battery cell of any one of claims 4 to 6, wherein, ​ 8. The battery cell of any one of claims 4 to 7, wherein, ​ 9. The battery cell of any one of claims 4 to 8, wherein, ​ 10. The battery cell of claim 9, wherein, ​ ​ ​ 11. The battery cell of any one of claims 4 to 10, wherein, ​ ​ ​ ​ 12. The battery cell of claim 11, wherein, ​ ​ ​ 13. The battery cell of any one of claims 4 to 12, wherein, ​ ​ ​ 14. The battery cell of claim 13, wherein, The temperature of the vulcanization molding is 140-200 DEG C, and the pressure of the vulcanization molding is 8-20 MPa.

15. The battery cell of any one of claims 1 to 14, wherein, The mass change rate of the rubber seal is less than 40% and the volume expansion rate is less than 40% after the rubber seal is soaked in dimethyl carbonate solvent at 70 DEG C for 72 hours.

16. The battery cell of any one of claims 1 to 15, wherein, According to the test of national standard GB / T 7759.1, the compression permanent deformation rate of the rubber seal is less than 30% after being compressed at 120 DEG C for 9 days.

17. The battery cell of any one of claims 1 to 16, wherein, The rubber seal has a volume resistivity > 1 x 10 10 Ω·cm at a test voltage of 500 V according to national standard GBT 31838.2-2019. 10 Ω·cm at a test voltage of 500 V according to national standard GBT 31838.2-2019. 10 Ω·cm at a test voltage of 500 V according to national standard GBT 18. The battery cell of any one of claims 1 to 17, wherein, The tensile strength of the rubber seal is greater than or equal to 14.0 MPa, and the elongation at break is greater than or equal to 130%.

19. The battery cell of any one of claims 1 to 18, wherein, The electric core assembly comprises a positive electrode sheet, a separator and a negative electrode sheet which are stacked; the battery monomer further comprises an electrolyte, the electrolyte is arranged in the shell, and the electric core assembly is soaked in the electrolyte.

20. A battery comprising the battery monomer according to any one of claims 1 to 19.

21. An electric device comprising at least one of the battery monomer according to any one of claims 1 to 19 and the battery according to claim 20.

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