Battery device, method of manufacturing the same, and electric device

Abstract

The application provides a battery device and a preparation method thereof and an electric device, wherein the battery device comprises: a box assembly having an accommodating cavity inside; and a battery monomer assembly comprising a plurality of battery monomers, wherein the battery monomers are provided with pressure relief valves facing the inner wall surface of the box assembly, and the pressure relief valves are configured to release the pressure inside the battery monomers; wherein the box assembly comprises an outer shell and a protective layer, the protective layer is arranged on the side of the outer shell facing the accommodating cavity, the pressure relief valves are arranged opposite to the protective layer, the protective layer comprises ceramicized silicone rubber, and the protective layer is integrally formed with the outer shell by calendering. The battery device has excellent safety performance.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery device and its preparation method, and an electrical device. Background Technology

[0002] In recent years, with economic development, battery technology has been widely applied in various fields, especially in the field of new energy vehicles. Currently, new energy vehicles have had a significant impact on traditional gasoline-powered vehicles. As a core component of new energy vehicles, batteries play a crucial role in their development.

[0003] In the development of battery technology, improving battery safety is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This application was made in view of the above-mentioned problems, and its purpose is to provide a battery device, a method for manufacturing the same, and an electrical device thereof. The battery device of this application has excellent safety performance.

[0005] To achieve the above objectives, a first aspect of this application provides a battery device, including a housing assembly having an internal receiving cavity; a battery cell assembly comprising a plurality of battery cells, each battery cell having a pressure relief valve disposed facing the inner wall of the housing assembly, the pressure relief valve being configured to release pressure inside the battery cell; wherein, the housing assembly includes a shell and a protective layer, the protective layer being disposed on the side of the shell facing the receiving cavity, the pressure relief valve being disposed opposite to the protective layer, the protective layer comprising ceramicized silicone rubber, and the protective layer being integrally formed by calendering with the shell.

[0006] In this application, ceramicized silicone rubber has the characteristics of no dripping and no release of toxic gases, which gives it strong fire resistance and flame retardancy, as well as good physical strength and thermal shock resistance. Therefore, the protective layer made of ceramicized silicone rubber is placed on the inner wall of the outer shell facing the pressure relief valve. The protective layer can resist the high-temperature spray released through the pressure relief valve, thereby protecting the outer shell of the housing assembly. This helps to improve the thermal shock resistance of the housing assembly and thus improves the safety performance of the battery device.

[0007] In addition, the integrated calendering of the protective layer and the outer shell eliminates the need for additional connecting structures between them, resulting in a better bond and improved impact resistance. Furthermore, the high damping factor of silicone rubber reduces the risk of vibration and noise from the shell, thus improving vehicle NVH.

[0008] In some embodiments, the housing includes a cover plate and a base plate; the protective layer is disposed on the base plate and / or the cover plate. This provides protection for the base plate and / or the cover plate, thereby improving the impact resistance of the housing assembly and consequently enhancing the safety performance of the battery device.

[0009] In some embodiments, the ceramicized silicone rubber comprises a silicone rubber matrix, a ceramic filler, a thermal insulation material, a flame retardant material, and a fluxing material, wherein the mass ratio of the silicone rubber matrix, the ceramic filler, the thermal insulation material, the flame retardant material, and the fluxing material is (0.6–1):(0.3–0.9):(0.1–0.6):(0.2–0.6):(0.04–0.16). The silicone rubber matrix and the ceramic filler can undergo a eutectic reaction and ceramicize under thermal runaway (or at high temperatures), resulting in a ceramicized silicone rubber with greater hardness and the ability to withstand thermal shock, thus improving the impact resistance of the enclosure assembly. The thermal insulation material and the flame retardant material further enhance the flame retardancy of the protective layer, making it more resistant to high-temperature projectiles from the pressure relief valve, further improving the impact resistance of the enclosure assembly and the safety performance of the battery device. Furthermore, the flame retardant material can make the ceramicization effect of the ceramicized silicone rubber more pronounced, further enhancing the impact resistance of the enclosure assembly and the safety performance of the battery device. Fluxing materials can lower the ceramization temperature of the protective layer and increase its strength, thereby improving its flame retardant and fire-resistant properties. When the mass ratio of silicone rubber matrix, ceramic filler, thermal insulation material, flame retardant material, and fluxing material is within the aforementioned range, it is beneficial to form a protective layer with excellent flame retardant, fire-resistant, and thermal shock-resistant properties.

[0010] In some embodiments, one or more of the following features are included: (1) the silicone rubber matrix accounts for 30% to 50% of the mass of the ceramicized silicone rubber; (2) the ceramic filler accounts for 15% to 45% of the mass of the ceramicized silicone rubber; (3) the thermal insulation material accounts for 5% to 30% of the mass of the ceramicized silicone rubber; (4) the flame retardant material accounts for 10% to 30% of the mass of the ceramicized silicone rubber; and (5) the fluxing material accounts for 2% to 8% of the mass of the ceramicized silicone rubber.

[0011] In some embodiments, one or more of the following features are included: (1) the ceramic filler includes one or more of muscovite, phlogopite, kaolin, brucite, talc, calcium silicate, aluminum silicate, and aluminum hydroxide; (2) the heat insulation material includes one or more of spherical glass microspheres, ceramic hollow microspheres, fly ash hollow microspheres, silica hollow microspheres, and bubble polycrystalline silicon hollow microspheres; (3) the flame retardant material includes one or more of magnesium hydroxide, aluminum hydroxide, magnesium silicate, calcium silicate, zinc borate, and low melting point glass powder; (4) the fluxing material includes one or more of zinc borate, boron oxide, zinc oxide, and low melting point glass powder.

[0012] In some embodiments, the ceramicized silicone rubber further includes reinforcing agents; the reinforcing agents constitute 5% to 12% of the ceramicized silicone rubber by mass. The reinforcing agents can increase the mechanical properties and thermal stability of the protective layer, further improving the impact resistance of the housing assembly and the safety performance of the battery device.

[0013] In some embodiments, the reinforcing agent includes silica and / or fibers.

[0014] In some embodiments, the ceramicized silicone rubber further includes a dispersing agent; the dispersing agent accounts for 0.5% to 2% of the mass of the ceramicized silicone rubber. The dispersing agent can make the ceramicized silicone rubber more compact, which is beneficial to improving the hardness of the protective layer, and can also improve the high temperature resistance and flame retardant properties of the ceramicized silicone rubber.

[0015] In some embodiments, the dispersing agent includes one or more of silane coupling agents, silicone oil, white oil, fatty acid salts, and silicone powder.

[0016] In some embodiments, the thickness of the protective layer is 0.3 mm to 3 mm. This allows for a balance between the safety performance and energy density of the battery device.

[0017] The second aspect of this application provides a method for manufacturing a battery device, including the preparation of a housing assembly. The preparation of the housing assembly includes the following steps: S1, preparing a compound rubber; S2, placing the compound rubber on the inner side of a housing and performing vulcanization calendering treatment using a calendering integral molding and curing process to obtain a protective layer located on the inner side of the housing, the protective layer comprising ceramicized silicone rubber; S3, assembling the housing with the protective layer into a housing assembly, wherein the housing assembly has an internal receiving cavity, the receiving cavity being disposed of a battery cell assembly, the battery cell assembly comprising multiple battery cells, each battery cell having a pressure relief valve disposed facing the inner wall surface of the housing assembly, the pressure relief valve being configured to release the pressure inside the battery cell; the protective layer is located on the side of the housing facing the receiving cavity, and the protective layer is disposed opposite to the pressure relief valve.

[0018] In this application, a protective layer located on the inner side of the outer casing can be prepared using a calendering integral molding and curing process. The protective layer has no additional connecting structure with the outer casing, exhibiting strong adhesion and improving the impact resistance of the outer casing. Furthermore, the protective layer prepared in this application faces the pressure relief valve inside the housing assembly. Therefore, the protective layer can resist high-temperature projectiles ejected from the pressure relief valve, thereby improving the impact resistance of the housing assembly and ultimately enhancing the safety performance of the battery device.

[0019] In some embodiments, step S1 includes a kneading step and a mixing step; the kneading step includes weighing 30-50 parts by weight of silicone rubber, 15-45 parts by weight of ceramic filler, 5-30 parts by weight of heat insulation material, 10-30 parts by weight of flame retardant material, and 2-8 parts by weight of fluxing material, and kneading them to obtain a base rubber; the mixing step includes mixing the vulcanizing agent and the base rubber to obtain the mixed rubber.

[0020] In some embodiments, the kneading step further includes weighing 5 to 12 parts by weight of reinforcing agent and performing the kneading treatment to obtain the base adhesive.

[0021] In some embodiments, the kneading step further includes weighing 0.5 to 2 parts by weight of a dispersing agent and performing the kneading treatment to obtain the base adhesive.

[0022] In some embodiments, the kneading process is carried out at a rotation speed of 18 r / min to 40 r / min and at a temperature of 25°C to 120°C for 35 min to 50 min. This facilitates the uniform dispersion of silicone rubber, ceramic filler, thermal insulation material, flame retardant material, and fluxing agent.

[0023] In some embodiments, the mixing process is carried out at a rotation speed of 20 r / min to 30 r / min and at a temperature of 105°C to 120°C for 35 min to 40 min. This is beneficial for further improving the dispersion uniformity of ceramic fillers, heat insulation materials, flame retardant materials, and fluxing materials in silicone rubber.

[0024] In some embodiments, the vulcanizing agent includes one or more of platinum vulcanizing agent, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,4-dichlorobenzoyl peroxide.

[0025] In some embodiments, the amount of the vulcanizing agent added is 0.3% to 1.2% of the amount of the base rubber added. This is beneficial for establishing the crosslinking density of the silicone rubber.

[0026] In some embodiments, in step S2, the vulcanization calendering treatment is carried out at 120°C to 180°C for 4 to 10 minutes. This is beneficial for building the crosslinking density of the silicone rubber and for improving the bonding strength with the substrate interface.

[0027] The third aspect of this application provides an electrical device, including the battery device provided in the first aspect of this application, or including a battery device prepared by the preparation method of the second aspect of this application. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a battery cell according to one embodiment of this application;

[0029] Figure 2 yes Figure 1 An exploded view of a single battery cell is shown.

[0030] Figure 3 This is a schematic diagram of a battery module according to one embodiment of this application;

[0031] Figure 4 This is a schematic diagram of a battery pack according to one embodiment of this application;

[0032] Figure 5 yes Figure 4 An exploded view of the battery pack shown.

[0033] Figure 6 This is a schematic diagram of a power supply device using a battery device according to an embodiment of this application.

[0034] Figure 7 These are the temperature curves of the front and back sides of the protective layer in Embodiment 1 of this application;

[0035] Figure 8This is a schematic diagram of the front and back sides of the protective layer after it has been ablated in Embodiment 1 of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1 Battery pack; 2 First housing; 3 Second housing; 4 Battery module; 5 Battery cell; 51 Housing; 52 Electrode assembly; 53 Top cover assembly. Detailed Implementation

[0038] The following detailed description, with appropriate reference to the accompanying drawings, discloses the battery device and its manufacturing method, as well as embodiments of the power-using device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0039] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0041] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0042] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0043] Unless otherwise specified, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0044] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be determined using various testing methods commonly used in the art, for example, according to the testing methods given in this application.

[0045] With the widespread application of new energy vehicles, batteries are extensively used as power output devices. Batteries typically consist of a housing assembly and multiple individual battery cells within it. When a battery cell experiences thermal runaway, it generates high-temperature gases and / or flames, which are released into the housing assembly through the cell's explosion-proof valve. When the pressure relief valve is inverted, the downward-spraying high-temperature material can easily melt through the housing assembly's base plate, leading to an open flame. This results in low battery safety and poses a threat to the safety of passengers.

[0046] Based on this, this application proposes a new battery device and an electrical device, the battery device of which has excellent safety performance.

[0047] Battery device

[0048] The first aspect of this application provides a battery device, including a housing assembly having an internal receiving cavity; a battery cell assembly including a plurality of battery cells, each battery cell having a pressure relief valve disposed facing the inner wall of the housing assembly, the pressure relief valve being configured to release pressure inside the battery cell; wherein, the housing assembly includes a shell and a protective layer, the protective layer being disposed on the side of the shell facing the receiving cavity, the pressure relief valve being disposed opposite to the protective layer, the protective layer being made of ceramicized silicone rubber, and the protective layer being integrally formed with the shell by calendering.

[0049] In this application, ceramicized silicone rubber has the characteristics of no dripping and no release of toxic gases, which gives it strong fire resistance and flame retardancy, as well as good physical strength and thermal shock resistance. Therefore, the protective layer made of ceramicized silicone rubber is placed on the inner wall of the outer shell facing the pressure relief valve. The protective layer can resist the high-temperature spray released through the pressure relief valve, thereby protecting the outer shell of the housing assembly. This helps to improve the thermal shock resistance of the housing assembly and thus improves the safety performance of the battery device.

[0050] In addition, the integrated calendering of the protective layer and the outer shell eliminates the need for additional connecting structures between them, resulting in a better bond and improved impact resistance. Furthermore, the high damping factor of silicone rubber reduces the risk of vibration and noise from the shell, thus improving vehicle NVH.

[0051] Furthermore, since ceramicized silicone rubber has corrosion resistance, when the protective layer of ceramicized silicone rubber is integrally molded with the outer shell, it can also protect the outer shell from electrolyte corrosion, which is beneficial for the maintenance and repair of the outer shell and extends the service life of the enclosure components and battery devices.

[0052] Furthermore, since ceramicized silicone rubber has anti-corrosion properties, the protective layer can replace the electrophoretic layer, PC sheet and mica board originally set on the inner wall of the housing assembly. This can save space inside the housing assembly and achieve weight reduction, which is beneficial to improving the energy density of the battery.

[0053] In this application, the "calendering integration" of the protective layer and the outer shell refers to the protective layer being formed on the outer shell through calendering, thus making the outer shell and the protective layer a single unit for simultaneous use. Calendering ensures, on the one hand, that the protective layer bonds better and more evenly to the outer shell, preventing detachment or cracking due to poor adhesion. On the other hand, the calendering process makes the molecular structure of the protective layer more compact, reducing pores and gaps, thereby improving its impact resistance and enabling it to better withstand external impacts and compression. Furthermore, calendering typically has high production efficiency, enabling rapid formation and curing of the protective layer. Compared to other processes, calendering also reduces raw material waste and energy consumption during processing, thus lowering production costs.

[0054] In some embodiments, the housing includes a cover plate and a base plate; a protective layer is disposed on the base plate and / or the cover plate. This provides protection for the base plate and / or the cover plate, thereby improving the impact resistance of the housing assembly and consequently enhancing the safety performance of the battery device.

[0055] In this application, when the pressure relief valve is in an upright position, the valve nozzle faces the cover plate of the housing assembly. At this time, the protective layer is set on the inner side of the cover plate. This allows the protective layer to resist the high-temperature spray from the pressure relief valve, thus protecting the cover plate of the housing assembly and improving the safety performance of the battery device.

[0056] In this application, when the pressure relief valve is an inverted structure, the pressure relief valve nozzle faces the bottom plate of the housing assembly. At this time, the protective layer is set on the inner side of the bottom plate. In this way, the high-temperature spray from the pressure relief valve can be resisted by the protective layer, thereby protecting the bottom plate of the housing assembly and thus improving the safety performance of the battery device.

[0057] In some embodiments, the housing assembly further includes a frame, with a base plate and a cover plate connected to the frame, creating a closed space (i.e., a receiving cavity) inside the housing to accommodate individual battery cells. When the pressure relief valve has a side-mounted structure, the valve nozzle faces the frame of the housing assembly, and a protective layer is disposed inside the frame facing the nozzle of the explosion-proof valve. This improves the impact resistance of the housing assembly and the safety performance of the battery device.

[0058] In some implementations, a bottom protective plate is also provided at the bottom of the housing assembly, and the protective layer may be located on the side of the bottom protective plate facing the housing assembly. This can further improve the safety performance of the battery device.

[0059] In some embodiments, the ceramized silicone rubber includes a silicone rubber matrix, ceramic fillers, thermal insulation materials, flame retardant materials, and fluxing materials. The silicone rubber matrix and ceramic fillers can undergo a eutectic reaction and ceramize during thermal runaway (or at high temperatures), resulting in greater hardness and improved thermal shock resistance of the silicone rubber, thus enhancing the impact resistance of the enclosure assembly. The thermal insulation and flame retardant materials further improve the flame retardancy of the protective layer, making it more resistant to high-temperature projectiles from the pressure relief valve, further improving the impact resistance of the enclosure assembly and the safety performance of the battery device. Furthermore, the flame retardant materials can further enhance the ceramization effect of the silicone rubber, further improving the impact resistance of the enclosure assembly and the safety performance of the battery device. The fluxing materials can lower the ceramization temperature of the protective layer and increase its strength, thereby improving its flame retardancy and fire resistance.

[0060] In some embodiments, the mass ratio of the silicone rubber matrix, ceramic filler, thermal insulation material, flame retardant material, and fluxing material is (0.6–1):(0.3–0.9):(0.1–0.6):(0.2–0.6):(0.04–0.16). This facilitates the formation of a protective layer with excellent flame retardant, fire-resistant, and thermal shock resistance properties. For example, the mass ratios of the silicone rubber matrix, ceramic filler, thermal insulation material, flame retardant material, and fluxing material are 0.6:0.3:0.1:0.2:0.04, 1:0.9:0.6:0.6:0.16, 1:0.5:0.5:0.5:0.1, 1:0.4:0.2:0.3:0.1, and 0.8:0.4:0.4:0.3:0.1.

[0061] In some embodiments, the silicone rubber matrix includes one or more of dimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, fluorosilicone rubber, and α,ω-dihydroxypolydimethylsiloxane.

[0062] In some embodiments, the silicone rubber matrix accounts for 30% to 50% of the mass of the ceramicized silicone rubber. This allows for the uniform dispersion of ceramic fillers, which is beneficial for forming a dense and hard ceramic body during thermal runaway. Exemplarily, the mass percentage of the silicone rubber matrix in the ceramicized silicone rubber is 30%, 35%, 40%, 45%, 50%, or a value within a range of any two of these values.

[0063] In some embodiments, the ceramic filler includes one or more of muscovite, phlogopite, kaolin, brucite, talc, calcium silicate, aluminum silicate, and aluminum hydroxide.

[0064] In some embodiments, the ceramic filler constitutes 15% to 45% of the mass of the ceramicized silicone rubber. This helps to improve the impact resistance of the housing assembly and the safety performance of the battery device. Exemplarily, the mass percentage of the ceramic filler in the ceramicized silicone rubber is a value within the range of 15%, 20%, 25%, 30%, 35%, 40%, 45%, or any two of these values.

[0065] In some embodiments, the thermal insulation material accounts for 5% to 30% of the mass of the ceramicized silicone rubber. This provides thermal insulation without compromising the fire resistance and flame retardancy of the ceramicized silicone rubber, thus improving the impact resistance of the enclosure assembly and the safety performance of the battery device. For example, the mass percentage of the thermal insulation material in the ceramicized silicone rubber is 5%, 10%, 15%, 20%, 25%, 30%, or any combination of two of these values.

[0066] In some embodiments, the thermal insulation material includes one or more of the following: spherical glass microspheres, ceramic hollow microspheres, fly ash hollow microspheres, silica hollow microspheres, and bubble polycrystalline silicon hollow microspheres. These materials have a hollow internal structure and low thermal conductivity, which greatly reduces heat transfer. Therefore, using these materials as thermal insulation materials provides excellent thermal insulation performance.

[0067] In some embodiments, the flame-retardant material constitutes 10% to 30% of the ceramicized silicone rubber by mass. This balances the flame-retardant and fire-resistant properties of the protective layer, improving the impact resistance of the housing assembly and the safety performance of the battery device. Exemplarily, the flame-retardant material constitutes 10%, 15%, 20%, 25%, 30% of the ceramicized silicone rubber by mass, or a value within the range of any two of these values.

[0068] In some embodiments, the flame-retardant material includes one or more of magnesium hydroxide, aluminum hydroxide, magnesium silicate, calcium silicate, zinc borate, and low-melting-point glass powder. These materials can reduce the combustion rate and inhibit the combustion reaction to varying degrees, thereby further improving the flame-retardant capability of the protective layer.

[0069] In some embodiments, the fluxing material constitutes 2% to 8% of the mass of the ceramicized silicone rubber. This improves the fire resistance and flame retardancy of the ceramicized silicone rubber, thereby enhancing the impact resistance of the housing assembly and the safety performance of the battery device. Exemplarily, the fluxing material constitutes 2%, 3%, 4%, 5%, 6%, 7%, 8%, or any combination of two of these values ​​within a range.

[0070] In some embodiments, the fluxing material includes one or more of zinc borate, boron oxide, zinc oxide, and low-melting-point glass powder. These materials can all lower the melting point, promote sintering, and enhance material properties at high temperatures; therefore, they can be used as fluxing materials.

[0071] In this application, when the battery cell experiences thermal runaway, the pressure relief valve ejects high-temperature gas. The silicone rubber matrix in the protective layer decomposes at high temperatures, and the generated silica undergoes a eutectic reaction with the ceramic filler, forming a liquid-phase eutectic at the edge of the ceramic filler. As the ablation temperature increases and time extends, the eutectic continuously diffuses, acting as a bridge between the silica particles and the ceramic filler particles. After cooling, a dense ceramic protective shell forms on the surface of the battery assembly casing. This ceramic protective shell effectively isolates the battery assembly casing from the outside environment, preventing heat transfer and flame erosion. Furthermore, the hollow structure of the insulating filler provides insulation and self-support, withstanding certain mechanical impacts and vibrations. Therefore, it protects the battery assembly casing from being ablated and melted by the high-temperature flames during battery cell thermal runaway, thereby improving the safety performance of the battery device.

[0072] In some embodiments, the protective layer further includes reinforcing agents; these reinforcing agents include silica and / or fibers. Reinforcing agents can increase the mechanical properties and thermal stability of the protective layer, further enhancing the impact resistance of the housing assembly and the safety performance of the battery device.

[0073] In some implementations, the fibers include glass fibers, ceramic fibers, basalt fibers, etc.

[0074] In some embodiments, silica comprises fumed silica.

[0075] In some embodiments, the reinforcing agent constitutes 5% to 12% of the ceramicized silicone rubber by mass. This is beneficial for improving the mechanical properties and thermal stability of the protective layer, thereby further enhancing the impact resistance of the housing assembly and the safety performance of the battery device. Exemplarily, the reinforcing agent constitutes 5%, 6%, 8%, 10%, 12% of the ceramicized silicone rubber by mass, or a value within the range of any two of these values.

[0076] In some embodiments, the ceramicized silicone rubber further includes dispersing agents; the dispersing agents include one or more of silane coupling agents, silicone oil, white oil, fatty acid salts, and silicone powder. Dispersing agents can, on the one hand, make the ceramicized silicone rubber denser, which is beneficial for improving the hardness of the protective layer; on the other hand, they can also improve the high-temperature resistance and flame-retardant properties of the ceramicized silicone rubber.

[0077] In some embodiments, the dispersing agent constitutes 0.5% to 2% of the ceramicized silicone rubber by mass. This is beneficial for improving the hardness, high-temperature resistance, and flame retardant properties of the ceramicized silicone rubber, and further enhances the impact resistance of the housing assembly and the safety performance of the battery device. Exemplarily, the dispersing agent constitutes 0.5%, 0.8%, 1%, 1.5%, 2%, or any combination of two of these values ​​by mass in the ceramicized silicone rubber.

[0078] In some embodiments, the thickness of the protective layer is 0.3 mm to 3 mm. A thickness within this range allows for the improvement of the impact resistance of the housing assembly and the safety performance of the battery device without excessively occupying the internal space of the housing assembly, thus balancing the safety performance and energy density of the battery device. For example, the thickness of the protective layer is a value within the range of 0.3 mm, 1 mm, 2 mm, 3 mm, or any two of these values.

[0079] In this application, the silicone rubber matrix, ceramic filler, heat insulation material, flame retardant material, fluxing material, reinforcing agent, and dispersing agent in the ceramicized silicone rubber can be tested using a Fourier transform infrared spectrometer. Specifically, the ceramicized silicone rubber sample is mixed with an infrared-transmitting material to form a thin film, which is then placed in the sample chamber of the Fourier transform infrared spectrometer. The instrument is started, preheated, and the instrument parameters are adjusted before testing to obtain the infrared spectral data of the ceramicized silicone rubber. The collected infrared spectral data is processed and analyzed using professional software to identify characteristic absorption peaks and determine the silicone rubber matrix, ceramic filler, heat insulation material, flame retardant material, fluxing material, reinforcing agent, and dispersing agent in the ceramicized silicone rubber based on the characteristic absorption peaks.

[0080] In this application, the thickness of the protective layer can be tested using a thickness gauge.

[0081] In some implementations, a battery cell assembly is used to provide voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0082] In some implementations, a battery cell assembly is typically formed by arranging multiple battery cells.

[0083] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0084] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0085] In some embodiments, the battery device may be a battery pack, which includes a housing assembly and one or more individual battery cells housed within the housing assembly.

[0086] As an example, the battery cell assembly can be a battery module, which can be housed in the housing by fixing the battery module in the housing assembly.

[0087] As an example, battery cell assemblies can also be housed within a housing assembly by directly fixing multiple battery cells to the housing assembly.

[0088] In some embodiments, the housing assembly may be part of the vehicle's chassis structure. For example, a portion of the housing assembly may be at least a portion of the vehicle's floor, or a portion of the housing assembly may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0089] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0090] In some implementations, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used.

[0091] For example, the battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0092] In some embodiments, the battery cell includes a housing and electrode assemblies. The housing is the outer protective shell of the battery cell, and has an internal cavity formed for encapsulating components such as the electrode assemblies and electrolyte. The housing can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite shell), or aluminum-plastic film, etc.

[0093] In some embodiments, the electrode assembly is the component within the battery cell where electrochemical reactions occur. The electrode assembly is typically stacked along the thickness direction (stack direction) of the battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode plates. The separator, positioned between the positive and negative electrode plates, prevents short circuits while allowing active ions to pass through.

[0094] In some embodiments, the positive electrode may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0095] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0096] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver-treated aluminum or stainless steel, copper, nickel, or titanium can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0097] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this disclosure is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0098] In some embodiments, the positive electrode sheet can be made of foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or a foamed alloy, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0099] In some implementations, the negative electrode may include a negative current collector.

[0100] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, copper, nickel, carbon, or titanium. The composite current collector may include a polymer base layer and a metal layer. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or foamed alloys. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). In some embodiments, the positive electrode current collector can be made of aluminum, and the negative electrode current collector can be made of copper.

[0101] This application does not impose any particular restrictions on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0102] In some embodiments, the material of the separator can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0103] This application does not impose specific restrictions on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel, or completely solid.

[0104] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0105] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0106] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0107] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0108] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0109] In some implementations, the electrode assembly is a stacked structure.

[0110] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0111] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0112] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0113] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0114] As an example, the separator can be continuously installed between any adjacent positive or negative electrode plates by folding or rolling.

[0115] In some embodiments, the electrode assembly is provided with tabs that can either draw current from or introduce current into the electrode assembly. The tabs include positive and negative tabs.

[0116] In some embodiments, the battery cell may include an outer packaging. This outer packaging can be used to encapsulate the electrode assembly and electrolyte described above.

[0117] In some embodiments, the outer packaging of the battery cell can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of the battery cell can also be a flexible package, such as a pouch. The material of the flexible package can be plastic; examples of plastics include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0118] This application does not impose any particular limitation on the shape of the battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 1 This is a schematic diagram of a battery cell according to one embodiment of this application. Figure 1 A square-structured battery cell 5 is shown.

[0119] In some implementations... Figure 2 yes Figure 1 The exploded view of the battery cell shown is for reference. Figure 2 The outer packaging may include a housing 51 and a top cover assembly 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the top cover assembly 53 can cover the opening to close the receiving cavity. A positive electrode sheet, a negative electrode sheet, and a separator can be formed into an electrode assembly 52 through a winding process or a stacking process. The electrode assembly 52 is encapsulated within the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The number of electrode assemblies 52 contained in a single battery cell 5 can be one or more, which can be selected by those skilled in the art according to specific practical needs.

[0120] Figure 3 This is a schematic diagram of a battery module according to one embodiment of this application, with reference to... Figure 3 In the battery module 4, multiple battery cells 5 can be arranged sequentially along the length of the battery module 4. Of course, they can also be arranged in any other way. Furthermore, these multiple battery cells 5 can be fixed in place using fasteners.

[0121] Optionally, the battery module 4 may also include a housing with a receiving space in which multiple battery cells 5 are received.

[0122] Figure 4 This is a schematic diagram of a battery pack according to one embodiment of this application. Figure 5 yes Figure 4 The exploded view of the battery pack shown is for reference only. Figure 4 and Figure 5 The battery pack 1 may include a housing assembly and multiple battery modules 4 disposed within the housing assembly. The housing assembly includes a first housing 2 and a second housing 3, wherein the first housing 2 can cover the second housing 3 and form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery pack.

[0123] Method for preparing battery devices

[0124] The second aspect of this application provides a method for preparing a battery device, comprising the following steps: S1, preparing a compound rubber; S2, placing the compound rubber on the inner side of a shell and performing vulcanization calendering treatment using a calendering integral molding and curing process to obtain a protective layer located on the inner side of the shell, the protective layer comprising ceramicized silicone rubber; S3, assembling the shell with the protective layer into a housing assembly, wherein the housing assembly has a receiving cavity inside, a battery cell assembly is disposed inside the receiving cavity, the battery cell assembly includes multiple battery cells, the battery cells have a pressure relief valve disposed facing the inner wall surface of the housing assembly, the pressure relief valve is configured to release the pressure inside the battery cell; the protective layer is located on the side of the shell facing the receiving cavity, and the protective layer is disposed opposite to the pressure relief valve.

[0125] In this application, a protective layer located on the inner side of the outer casing can be prepared using a calendering integral molding and curing process. The protective layer has no additional connecting structure with the outer casing, exhibiting strong adhesion and improving the impact resistance of the outer casing. Furthermore, the protective layer prepared in this application faces the pressure relief valve inside the housing assembly. Therefore, the protective layer can resist high-temperature projectiles ejected from the pressure relief valve, thereby improving the impact resistance of the housing assembly and ultimately enhancing the safety performance of the battery device.

[0126] In addition, since the protective layer prepared in this application includes ceramicized silicone rubber, which has anti-corrosion properties, it can replace the electrophoretic layer, polycarbonate insulating sheet (PC sheet) and mica board originally set on the bottom plate of the battery box. In this way, at least the electrophoresis process can be eliminated, simplifying the preparation process of the box assembly.

[0127] In some embodiments, step S1 includes a kneading step and a mixing step; the kneading step includes weighing 30-50 parts by weight of silicone rubber, 15-45 parts by weight of ceramic filler, 5-30 parts by weight of heat insulation material, 10-30 parts by weight of flame retardant material and 2-8 parts by weight of fluxing material, and kneading them to obtain a base rubber; the mixing step includes mixing the vulcanizing agent and the base rubber to obtain a compound rubber.

[0128] Thermal insulation and flame-retardant materials can further enhance the flame-retardant capability of the protective layer, making it more resistant to high-temperature projectiles from the pressure relief valve, thus improving the impact resistance of the enclosure components and the safety performance of the battery device. Additionally, flame-retardant materials can further enhance the ceramization effect of the ceramized silicone rubber, further improving the impact resistance of the enclosure components and the safety performance of the battery device. Flux materials can also enhance the ceramization effect of the silicone rubber, thereby lowering the ceramization temperature of the protective layer, increasing its strength, and ultimately improving its flame-retardant and fire-resistant properties.

[0129] In some embodiments, the kneading process can be performed in three steps. First, 15-45 parts by weight of ceramic filler, 5-30 parts by weight of heat insulation material, 10-30 parts by weight of flame retardant material, and 2-8 parts by weight of fluxing material are weighed and mixed evenly to form a mixed powder. Then, 30-50 parts by weight of silicone rubber, 60% of the mixed powder, and 2% of silicone oil are weighed and kneaded in a kneader. Next, 25% of the mixed powder and 1.5% of the silicone oil are added and kneaded in the kneader. Finally, 15% of the mixed powder and 1.0% of the silicone oil are added and kneaded in the kneader. Through multiple kneading processes, the components can be mixed more evenly. In addition, adding silicone oil during the kneading process is more conducive to the dispersion of ceramic filler, heat insulation material, flame retardant material, and fluxing material.

[0130] In some embodiments, the ceramic-forming filler includes one or more of muscovite, phlogopite, kaolin, brucite, talc, calcium silicate, aluminum silicate, and aluminum hydroxide; optionally, the ceramic-forming filler includes muscovite. Muscovite has a small particle size and good ceramization effect, therefore, the prepared protective layer has high strength.

[0131] In some embodiments, the average particle size of muscovite is 15 μm to 250 μm. This allows for a balance between the ceramization effect and the shrinkage rate of the protective layer, resulting in a protective layer with both high strength and a suitable shrinkage rate.

[0132] In some embodiments, the silicone rubber includes one or more of dimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, fluorosilicone rubber, and α,ω-dihydroxypolydimethylsiloxane.

[0133] In some embodiments, the weight-average molecular weight of the silicone rubber is 80,000 to 500,000.

[0134] It should be noted that after vulcanization, silicone rubber undergoes cross-linking between molecules to form a macromolecular silicone rubber matrix.

[0135] In some embodiments, the thermal insulation material includes one or more of the following: spherical glass microspheres, ceramic hollow microspheres, fly ash hollow microspheres, silica hollow microspheres, and bubble polycrystalline silicon hollow microspheres. These materials have a hollow internal structure and low thermal conductivity, which greatly reduces heat transfer. Therefore, using these materials as thermal insulation materials provides excellent thermal insulation performance.

[0136] In some embodiments, the flame-retardant material includes one or more of magnesium hydroxide, aluminum hydroxide, magnesium silicate, calcium silicate, zinc borate, and low-melting-point glass powder. These materials can reduce the combustion rate and inhibit the combustion reaction to varying degrees, thereby further improving the flame-retardant capability of the protective layer.

[0137] In some embodiments, the fluxing material includes one or more of zinc borate, boron oxide, zinc oxide, and low-melting-point glass powder. These materials can all lower the melting point, promote sintering, and enhance material properties at high temperatures; therefore, they can be used as fluxing materials.

[0138] In some embodiments, the fluxing material includes low-melting-point glass powder. Low-melting-point glass powder has a low softening temperature, and upon reaching the appropriate temperature, it forms a molten liquid phase that flows between the surrounding ceramic filler particles, effectively coating them. The longer the time, the more liquid phase is formed by the low-melting-point glass powder. After the temperature drops and the material solidifies, it can act as a bridge, thereby improving the strength of the formed protective layer.

[0139] In some embodiments, the kneading step further includes weighing 5 to 12 parts by weight of reinforcing additives and kneading them to obtain the base material adhesive. The reinforcing additives can increase the mechanical properties and thermal stability of the protective layer, further improving the impact resistance of the housing assembly and the safety performance of the battery device.

[0140] In some embodiments, the reinforcing agents include silica and / or fibers; alternatively, the reinforcing agents include glass fibers, ceramic fibers, basalt fibers, etc.

[0141] In some embodiments, silica comprises fumed silica.

[0142] In some embodiments, the kneading step further includes weighing 0.5 to 2 parts by weight of a dispersing agent and kneading it to obtain the base material. The addition of the dispersing agent can significantly improve the dispersibility and wettability of the ceramic filler in the silicone rubber, thereby enhancing the overall performance of the formed protective layer.

[0143] In some embodiments, the dispersing aid is one or more of the following: silane coupling agent, silicone oil, white oil, fatty acid salt, and silicone powder.

[0144] In some embodiments, during the kneading step, the kneading process is carried out at a rotation speed of 18 r / min to 40 r / min and at a temperature of 25°C to 120°C for 35 min to 50 min. Kneading under these conditions promotes the uniform dispersion of silicone rubber, ceramic filler, thermal insulation material, flame retardant material, and fluxing agent.

[0145] In some embodiments, during the mixing step, the mixing process is carried out at a rotation speed of 20 r / min to 30 r / min and at a temperature of 105°C to 120°C for 35 min to 40 min. Mixing under these conditions helps to further improve the dispersion uniformity of ceramic fillers, heat-insulating materials, flame-retardant materials, and fluxing materials in the silicone rubber.

[0146] In some embodiments, the vulcanizing agent includes one or more of platinum vulcanizing agent, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,4-dichlorobenzoyl peroxide. Optionally, the vulcanizing agent includes dicumyl peroxide.

[0147] In some embodiments, the amount of vulcanizing agent added is 0.3% to 1.2% of the amount of silicone rubber added. Exemplarily, the amount of vulcanizing agent added is 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, or any range of two such values, of the amount of base rubber added. Adding vulcanizing agent within the above range is beneficial for establishing the crosslinking density of the silicone rubber.

[0148] In some embodiments, in step S2, the vulcanization calendering treatment is carried out at 120°C to 180°C for 4 to 10 minutes; alternatively, the vulcanization calendering treatment is carried out at 150°C to 170°C for 5 to 8 minutes. Performing the vulcanization treatment under these conditions is beneficial for building the crosslinking density of the silicone rubber and for improving the bonding strength between the protective layer and the substrate interface.

[0149] Electrical appliances

[0150] Furthermore, a third aspect of this application provides an electrical device, which includes the battery device provided in the first aspect of this application, or a battery device prepared according to the preparation method of the second aspect of this application. The battery device can be used as a power source for the electrical device or as an energy storage unit of the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0151] As an electrical device, you can choose individual battery cells, battery modules, or battery packs according to your usage requirements.

[0152] Figure 6 This is a schematic diagram of an electrical device using a battery device as a power source according to one embodiment of this application. The electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of the secondary battery for this electrical device, a battery pack or battery module can be used.

[0153] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use a single battery cell as their power source.

[0154] Example

[0155] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0156] Example 1

[0157] Preparation of enclosure components:

[0158] S1, Prepare the compound; weigh and mix the raw materials according to the following formula: 20 parts by weight of ceramic filler mica (Shijiazhuang Chenxing Industrial Co., Ltd.), 10 parts by weight of heat insulation material hollow glass microspheres (Zhongke Huaxing New Materials Co., Ltd.), 15 parts by weight of flame retardant material aluminum hydroxide, calcium silicate, magnesium silicate, and zinc borate mixture (Anhui Yishitong Materials Technology Co., Ltd.), and 5 parts by weight of fluxing agent low melting point glass powder CFR-2. Then weigh 50 parts by weight of organosilicon rubber α,ω - Dihydroxypolydimethylsiloxane (Shandong Dongyue Organosilicon Materials Co., Ltd.), 60% of the mixed powder and 2% of silicone oil were kneaded in a kneader at 30 r / min and 25°C for 15 min; then 25% of the mixed powder and 1.5% of silicone oil were added and kneaded in a kneader at 30 r / min and 25°C for 15 min; then 15% of the mixed powder and 1% of silicone oil were added again and kneaded in a kneader at 30 r / min and 25°C for 15 min; the base material was obtained.

[0159] S2, take the above base rubber and add 0.8% of the vulcanizing agent 2,4-dichlorobenzoyl peroxide, then add it to an open mixing mill and process it at 25 r / min and 110°C for 35 min to obtain a compound rubber. The amount of vulcanizing agent added is 0.5% of the amount of base rubber added. Then, set the temperature of the flat vulcanizing mill to 120°C, preheat the mold until it stabilizes, and then spread the compound rubber evenly on the inner side of the bottom plate of the box assembly. After hot pressing at 10 MPa for 10 min, a one-piece molded bottom plate with a protective layer is formed; the thickness of the protective layer is 1 mm. The protective layer in Example 1 contains 50% silicone rubber matrix, 20% ceramic filler, 10% heat insulation material, 15% flame retardant material and 5% fluxing material.

[0160] S3, Assemble the base plate containing the protective layer obtained in step S2 into a box assembly.

[0161] Example 2

[0162] The housing assembly was prepared using the same method as in Example 1, except that the compound contained 40 parts by weight of α,ω-dihydroxypolydimethylsiloxane (Shandong Dongyue Organosilicon Materials Co., Ltd.), 20 parts by weight of muscovite (Shijiazhuang Chenxing Industrial Co., Ltd.), 20 parts by weight of hollow glass microspheres (Zhongke Huaxing New Materials Co., Ltd.), 15 parts by weight of a mixture of aluminum hydroxide, calcium silicate, magnesium silicate, and zinc borate (Anhui Yishitong Materials Technology Co., Ltd.), and 5 parts by weight of low-melting-point glass powder as a flux. The protective layer in Example 2 contained 40% silicone rubber matrix, 20% ceramic filler, 20% thermal insulation material, 15% flame retardant material, and 5% flux.

[0163] Example 3

[0164] The housing assembly was prepared using the same method as in Example 1, except that the compound contained 50 parts by weight of α,ω-dihydroxypolydimethylsiloxane (Shandong Dongyue Organosilicon Materials Co., Ltd.), 15 parts by weight of muscovite (Shijiazhuang Chenxing Industrial Co., Ltd.), 10 parts by weight of hollow glass microspheres (Zhongke Huaxing New Materials Co., Ltd.), 15 parts by weight of a mixture of aluminum hydroxide, calcium silicate, magnesium silicate, and zinc borate (Anhui Yishitong Materials Technology Co., Ltd.), 5 parts by weight of low-melting-point glass powder as flux, and 5 parts by weight of glass fiber as reinforcing agent. The protective layer in Example 3 contained 50% silicone rubber matrix, 15% ceramic filler, 10% thermal insulation material, 15% flame retardant material, 5% flux, and 5% reinforcing agent.

[0165] Example 4

[0166] The housing assembly was prepared using the same method as in Example 1, except that the compound contained 50 parts by weight of α,ω-dihydroxypolydimethylsiloxane (Shandong Dongyue Organosilicon Materials Co., Ltd.), 15 parts by weight of muscovite (Shijiazhuang Chenxing Industrial Co., Ltd.), 10 parts by weight of hollow glass microspheres (Zhongke Huaxing New Materials Co., Ltd.), 15 parts by weight of a mixture of aluminum hydroxide, calcium silicate, magnesium silicate, and zinc borate (Anhui Yishitong Materials Technology Co., Ltd.), 8 parts by weight of low-melting-point glass powder as flux, and 2 parts by weight of silane coupling agent (KH550) as dispersant. The protective layer in Example 4 contained 50% silicone rubber matrix, 15% ceramic filler, 10% thermal insulation material, 15% flame retardant material, 8% flux, and 2% dispersant.

[0167] Example 5

[0168] The housing assembly was prepared using the same method as in Example 1, except that the compound contained 50 parts by weight of α,ω-dihydroxypolydimethylsiloxane (Shandong Dongyue Organosilicon Materials Co., Ltd.), 15 parts by weight of muscovite (Shijiazhuang Chenxing Industrial Co., Ltd.), 10 parts by weight of hollow glass microspheres (Zhongke Huaxing New Materials Co., Ltd.), 10 parts by weight of a mixture of aluminum hydroxide, calcium silicate, magnesium silicate, and zinc borate (Anhui Yishitong Materials Technology Co., Ltd.), 8 parts by weight of low-melting-point glass powder as flux, 5 parts by weight of glass fiber as reinforcing agent, and 2 parts by weight of silane coupling agent (KH550) as dispersing agent. The protective layer in Example 5 contained 50% silicone rubber matrix, 15% ceramic filler, 10% thermal insulation material, 10% flame retardant material, 8% flux, 5% reinforcing agent, and 2% dispersing agent.

[0169] Comparative Example 1

[0170] The enclosure assembly does not include a protective layer.

[0171] Protective layer performance test

[0172] After the vulcanization and calendering treatment in step 2) above, a protective layer sample is prepared. The protective layer sample does not contain a base plate, but only the protective layer. Then, the following tests are performed on the protective layer sample.

[0173] (1) Tensile strength and elongation

[0174] Tensile strength and elongation can be tested using methods commonly used in the field, for example, according to Sections 6 and 7 of GB / T528-2009. Specifically, the testing environment is 23±2℃, 45%~55%RH; the protective layer sample is prepared as a Type 1 standard tensile specimen with a thickness of 2mm and a smooth, burr-free surface; the tensile specimen is fixed, the extensometer gauge length is 25mm, and one end is stretched using a tensile testing machine at a speed of 500±10mm / min. The tensile strength and elongation of the protective layer sample are measured, and the specific test results are shown in Table 2.

[0175] (2) Tear strength

[0176] Tear hardness can be tested using methods commonly used in the field, for example, according to GB / T529-2008. An external force is applied along the length of the specimen to a specified right-angled protective layer sample. The tensile speed of the right-angled sample is (500±50) mm / min, and the sample thickness is (2.0±0.2) mm. The tear strength of the protective layer sample is the maximum force required to tear it, divided by the sample thickness. Specific test results are shown in Table 2.

[0177] Enclosure component performance testing

[0178] (1) Fire resistance

[0179] The test was conducted using a butane flame torch, with the flame 10cm away from the protective layer and the flame temperature between 1000℃ and 1200℃. The temperature of the protective layer and the back of the base plate were tested.

[0180] Figure 7 These are the temperature curves of the front and back sides of the protective layer in Embodiment 1 of this application, such as... Figure 7 As shown, the protective layer was subjected to flame ablation at 1000℃~1200℃. The temperature on the front of the protective layer was about 600℃, while the temperature on the back (i.e., the base plate) was only about 300℃. This further demonstrates that the protective layer in this application has excellent fireproof, flame-retardant, and high-temperature resistance properties.

[0181] Figure 8 This is a schematic diagram of the front and back of the protective layer after it has been ablated in Embodiment 1 of this application. It can be seen that ablation marks are visible on the front of the protective layer after it has been ablated, while no ablation marks are visible on the back. Therefore, the protective layer in this application can protect the base plate from being eroded through.

[0182] (2) Volume resistivity before and after ablation

[0183] Volume resistivity can be tested using methods commonly used in this field. For example, it can be tested according to GB / T1692-2008, and the test results are shown in Table 2 below.

[0184] (3) Flame retardant rating

[0185] Flame retardancy ratings can be tested using methods commonly used in the field, such as referring to the UL94 vertical burning test. The test results are shown in Table 2 below.

[0186] Table 1 below shows the formulations of the compound rubbers in Examples 1 to 5.

[0187] Table 1

[0188]

[0189] In Table 1, " / " indicates that the item does not exist.

[0190] The performance test results of the protective layer and the housing assembly prepared in Examples 1 to 5 and Comparative Example 1 are shown in Table 2 below.

[0191] Table 2

[0192]

[0193]

[0194] In Table 2, " / " indicates that the item does not exist.

[0195] As can be seen from Tables 1 and 2, compared to Comparative Example 1 (without a protective layer), in Examples 1 to 5, by providing a protective layer on the base plate, no cracks appear on the base plate after burning, and the temperature on the back of the base plate is lower, significantly improving the fire resistance, flame retardancy, and high-temperature resistance of the housing assembly, thereby improving the safety performance of the battery device. Furthermore, the higher volume resistivity of the base plate after ablation reflects better insulation performance, indicating that the presence of the protective layer prevents short circuits during thermal runaway, which is beneficial to the insulation performance of the housing assembly and thus to the safety performance of the battery device. In addition, the performance test results of the protective layer in Examples 1 to 5 show that the tensile strength and tear strength of the protective layer are high, reflecting its fire-resistant impact resistance; the elongation of the protective layer is high, reflecting its certain elongation performance, which is beneficial to its bonding strength with the base plate. Furthermore, comparing Examples 1 to 4 and Example 5, the flame retardant rating of Examples 1 to 4 is higher than that of Example 5 because of the higher content of flame-retardant material.

[0196] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A battery device, characterized in that, include: The housing assembly has an internal cavity; A battery cell assembly, the battery cell assembly including a plurality of battery cells, each battery cell having a pressure relief valve disposed toward the inner wall surface of the housing assembly, the pressure relief valve being configured to release pressure inside the battery cell; The housing assembly includes an outer shell and a protective layer. The protective layer is disposed on the side of the outer shell facing the receiving cavity. The pressure relief valve is disposed opposite to the protective layer. The protective layer includes ceramicized silicone rubber and is integrally formed by calendering with the outer shell.

2. The battery device according to claim 1, characterized in that, The outer casing includes a cover plate and a bottom plate; the protective layer is disposed on the bottom plate and / or the cover plate.

3. The battery device according to claim 1 or 2, characterized in that, The ceramicized silicone rubber includes a silicone rubber matrix, ceramic filler, thermal insulation material, flame retardant material, and fluxing material. The mass ratio of the silicone rubber matrix, the ceramic filler, the thermal insulation material, the flame retardant material, and the fluxing material is (0.6-1):(0.3-0.9):(0.1-0.6):(0.2-0.6):(0.04-0.16).

4. The battery device according to claim 3, characterized in that, Includes one or more of the following features: (1) The mass percentage of the silicone rubber matrix in the ceramicized silicone rubber is 30% to 50%; (2) The ceramic filler accounts for 15% to 45% of the mass of the ceramicized silicone rubber; (3) The thermal insulation material accounts for 5% to 30% of the mass of the ceramicized silicone rubber; (4) The flame retardant material accounts for 10% to 30% of the mass of the ceramicized silicone rubber; (5) The fluxing material accounts for 2% to 8% of the mass of the ceramicized silicone rubber.

5. The battery device according to claim 3, characterized in that, Includes one or more of the following features: (1) The ceramic filler includes one or more of the following: muscovite, phlogopite, kaolin, brucite, talc, calcium silicate, aluminum silicate, and aluminum hydroxide; (2) The heat insulation material includes one or more of the following: spherical glass microspheres, ceramic hollow microspheres, fly ash hollow microspheres, silica hollow microspheres, and bubble polycrystalline silicon hollow microspheres; (3) The flame retardant material includes one or more of magnesium hydroxide, aluminum hydroxide, magnesium silicate, calcium silicate, zinc borate, and low melting point glass powder; (4) The fluxing material includes one or more of zinc borate, boron oxide, zinc oxide, and low melting point glass powder.

6. The battery device according to claim 3, characterized in that, The ceramicized silicone rubber also includes reinforcing agents; the reinforcing agents account for 5% to 12% of the mass of the ceramicized silicone rubber.

7. The battery device according to claim 6, characterized in that, The reinforcing agents include silica and / or fibers.

8. The battery device according to claim 3, characterized in that, The ceramicized silicone rubber also includes a dispersing agent; the dispersing agent accounts for 0.5% to 2% of the mass of the ceramicized silicone rubber.

9. The battery device according to claim 8, characterized in that, The dispersing agent includes one or more of the following: silane coupling agent, silicone oil, white oil, fatty acid salt, and silicone powder.

10. The battery device according to claim 1 or 2, characterized in that, The thickness of the protective layer is 0.3mm to 3mm.

11. A method for preparing a battery device, characterized in that, The preparation of the enclosure assembly includes the following steps: S1, prepare the compound rubber; S2, the compound is placed on the inner side of the shell and vulcanized and calendered using a calendering integral molding and curing process to obtain a protective layer on the inner side of the shell, the protective layer comprising ceramicized silicone rubber; S3, assemble the outer shell with the protective layer into the housing assembly, wherein the housing assembly has a receiving cavity inside, the receiving cavity is provided with a battery cell assembly, the battery cell assembly includes a plurality of battery cells, the battery cell has a pressure relief valve disposed facing the inner wall surface of the housing assembly, the pressure relief valve is configured to release the pressure inside the battery cell; The protective layer is located on the side of the outer shell facing the receiving cavity, and the protective layer is disposed opposite to the pressure relief valve.

12. The preparation method according to claim 11, characterized in that, Step S1 includes a kneading step and a mixing step; The kneading step includes weighing 30-50 parts by weight of silicone rubber, 15-45 parts by weight of ceramic filler, 5-30 parts by weight of heat insulation material, 10-30 parts by weight of flame retardant material and 2-8 parts by weight of fluxing material, and kneading them to obtain the base material. The mixing step includes mixing the vulcanizing agent and the base rubber to obtain the mixed rubber.

13. The preparation method according to claim 12, characterized in that, The kneading step further includes weighing 5 to 12 parts by weight of reinforcing agent and performing the kneading treatment to obtain the base material adhesive.

14. The preparation method according to claim 12 or 13, characterized in that, The kneading step further includes weighing 0.5 to 2 parts by weight of a dispersing agent and performing the kneading treatment to obtain the base adhesive.

15. The preparation method according to claim 12, characterized in that, The kneading process is carried out at a rotation speed of 18 r / min to 40 r / min and at a temperature of 25°C to 120°C for 35 min to 50 min.

16. The preparation method according to claim 12, characterized in that, The mixing process is carried out at a rotation speed of 20 r / min to 30 r / min and at a temperature of 105℃ to 120℃ for 35 min to 40 min.

17. The preparation method according to claim 12, characterized in that, The vulcanizing agent includes one or more of platinum vulcanizing agent, dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,4-dichlorobenzoyl peroxide.

18. The preparation method according to claim 17, characterized in that, The amount of the vulcanizing agent added is 0.3% to 1.2% of the amount of the base rubber added.

19. The preparation method according to claim 11, characterized in that, In step S2, the vulcanization calendering treatment is carried out at 120℃~180℃ for 4min~10min.

20. An electrical device, characterized in that, Includes the battery device according to any one of claims 1 to 10, or includes the battery device prepared by the preparation method according to any one of claims 11 to 19.

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