A power battery heat insulation protection assembly, a battery cell assembly and an electric device

Abstract

The application discloses a power battery heat insulation protection assembly, a battery cell assembly and a power utilization device, and relates to the technical field of new energy sources.The power battery heat insulation protection assembly comprises a first protection layer, a second protection layer and a third protection layer arranged in sequence in the thickness direction of the power battery heat insulation protection assembly, wherein the material of the power battery heat insulation protection assembly comprises ceramic fibers and aerogel;the volume proportion of the ceramic fibers in the first protection layer, the second protection layer and the third protection layer is arranged in a layer-by-layer decreasing manner;the volume proportion of the aerogel in the first protection layer, the second protection layer and the third protection layer is arranged in a layer-by-layer increasing manner;the first protection layer, the second protection layer and the third protection layer are further provided with micro flow channels for fluid to pass through; and the first protection layer, the second protection layer and the third protection layer are integrally formed.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a power battery heat insulation protection component, a battery cell component, and an electrical device. Background Technology

[0002] Currently, new energy vehicle power batteries are rapidly developing towards high-rate fast charging, high energy density, and integrated modules. These batteries have wide operating temperature ranges, rapid heat accumulation during charging and discharging, fast thermal runaway trigger speeds, high flame jet temperatures, and intense heat spread, placing extremely high demands on the comprehensive performance of battery protection materials and structures. Existing power battery thermal protection technologies are mainly divided into two categories: purely passive thermal insulation protection and purely active cooling and fire extinguishing protection. These technologies have significant shortcomings and cannot simultaneously meet the integrated protection requirements of long-term thermal insulation, extreme resistance to high-temperature shocks, and dynamic intelligent fire extinguishing. Summary of the Invention

[0003] This application provides a power battery heat insulation protection component, a cell component, and an electrical device to improve the shortcomings of poor stability of passive protection, low reliability of active protection, and insufficient adaptability to all working conditions.

[0004] In a first aspect, this application provides a power battery heat insulation and protection component, which includes a first protective layer, a second protective layer, and a third protective layer sequentially disposed in its thickness direction, wherein: The materials of the power battery heat insulation protection component include ceramic fiber and aerogel; The volume percentage of ceramic fibers in the first, second, and third protective layers decreases progressively. The volume percentage of aerogel in the first, second, and third protective layers increases progressively. The first, second, and third protective layers are also provided with microchannels for fluid to pass through; The first protective layer, the second protective layer, and the third protective layer are integrally formed.

[0005] This application employs a continuous gradient structure with a gradually changing volume ratio of ceramic fiber and aerogel, utilizing the difference in the thermal expansion coefficients of the two materials to progressively release thermal stress generated by thermal cycling. This reduces the problems of thermal cycling cracking, pulverization and detachment, and performance degradation caused by thermal stress concentration in traditional homogeneous structures, significantly extending the lifespan of the module and ensuring that the protective performance does not degrade throughout the entire battery life cycle. The microchannels and gradient substrate are integrally molded, eliminating the bonding or sewing interfaces between the traditional separate channels and the insulation layer. This solves the problems of channel detachment and leakage failure caused by adhesive carbonization and seam melting at high temperatures in traditional structures. At the same time, the tight connection reduces interlayer contact thermal resistance, allowing heat to be smoothly transferred from the high-temperature side to the microchannels and carried away, improving structural integrity and protective reliability under extreme thermal runaway conditions. A gradient insulation layer provides passive insulation under normal conditions, while microchannels provide active cooling / fire suppression under extreme conditions. This achieves full-cycle synergistic protection through passive insulation to prevent heat accumulation under normal conditions, intelligent pre-emptive control to prevent runaway, and active fire suppression to prevent the spread of heat. It covers the safety needs of the entire battery lifecycle and solves the problems of insufficient passive insulation to cope with thermal runaway and high energy consumption of active cooling alone. A high-fiber-content first protective layer blocks the intrusion of external high temperatures, while a high-aerogel-content third protective layer blocks the outward transfer of internal heat. Microchannels rapidly remove heat in the middle layer, achieving a two-way thermal management balance. This prevents both external fire sources from igniting the battery and internal overheating from igniting external sources, forming a two-way safety barrier. The three layers are tightly connected to form a single component, improving the overall mechanical strength of the module and enabling it to withstand vibrations and impacts within the battery pack, preventing displacement or loosening of the module during vehicle operation.

[0006] In some embodiments, the ceramic fiber includes at least one selected from basalt fiber, alumina fiber, quartz fiber, and aluminosilicate fiber; and / or, The aerogel includes at least one of silica aerogel, alumina aerogel, and zirconia aerogel.

[0007] Both the ceramic fiber and aerogel materials mentioned above have excellent resistance to electrolyte corrosion. They do not swell or decompose under battery leakage conditions, maintain stable protective performance, and reduce safety hazards caused by material failure. Basalt fiber possesses ultra-high temperature resistance, capable of withstanding instantaneous high-temperature jets exceeding 800°C, and exhibits excellent resistance to flame impact and thermal radiation. It can serve as a skeletal support to prevent components from being ablated and perforated during thermal runaway, ensuring structural stability under the impact of flame jets from the battery. Alumina aerogel and zirconia aerogel can further enhance the high-temperature resistance to an upper limit of 1000°C, making it suitable for extreme high heat flux density conditions.

[0008] Silica aerogel possesses a nanoporous structure and extremely low thermal conductivity, enabling long-lasting thermal insulation at room temperature. It effectively blocks heat transfer to the battery body, reducing heat accumulation caused by high ambient temperatures or thermal runaway from adjacent batteries, thus lowering air conditioning energy consumption. Alumina fibers and quartz fibers can enhance the ablation resistance and thermal shock resistance of the hot side.

[0009] In some embodiments, the ceramic fiber volume ratio in the first protective layer is 60% to 80%. This high fiber ratio in the first protective layer (hot side) can form a dense, high-temperature resistant barrier, possessing high-temperature resistance and flame impact resistance, reducing the probability of the substrate being ablated and perforated by high-temperature gas flow in the early stages of thermal runaway, thus ensuring the first line of defense does not fail; and / or, The volume percentage of ceramic fibers in the second protective layer is 20% to 60%. Specifically, the volume percentage of ceramic fibers in the second protective layer can gradually change from 40% to 60% near the first protective layer to 20% to 40% near the third protective layer. The composition of the second protective layer (middle layer) changes continuously and gradually, releasing heat flow step by step through a continuous gradient impedance. This both blocks heat transfer and mitigates thermal cycling stress, reducing delamination between layers due to abrupt material changes. As a result, the three-layer structure does not delaminate during long-term use, reducing cracking and differentiation; and / or, The ceramic fiber volume ratio in the third protective layer is 10%~20%. The third protective layer (cold side) has a high aerogel content, excellent thermal conductivity and flexibility, and can closely fit the irregular curved surface of the battery module, eliminating assembly gaps, reducing the risk of thermal short circuits caused by gaps, and reducing thermal insulation dead zones.

[0010] A higher fiber content results in higher strength, while a higher aerogel content results in better flexibility. This achieves a smooth transition in mechanical properties from high-strength support on the hot side to flexible buffering on the cold side, protecting the battery from impacts by hard objects while also preventing damage to the battery casing from hard contact.

[0011] In some embodiments, the thermal conductivity of the first protective layer at 25°C is 0.025 W / (m·K) to 0.035 W / (m·K); and / or, The second protective layer has a thermal conductivity of 0.018 W / (m·K) to 0.025 W / (m·K) at 25°C; and / or, The thermal conductivity of the third protective layer at 25°C is 0.012 W / (m·K) to 0.018 W / (m·K).

[0012] Through a gradient thermal conductivity design, with the first to third protective layers decreasing in thermal conductivity, heat flow is gradually consumed and attenuated during transfer, effectively blocking heat transfer to the battery body, reducing the battery temperature rise rate, and providing more reaction time for the thermal management system. The ultra-low thermal conductivity on the cold side (0.012 W / (m·K) ~ 0.018 W / (m·K)) enables long-lasting insulation at room temperature, preventing battery aging due to excessive environmental temperature differences and heat accumulation, ensuring the battery operates within a suitable temperature window, reducing the activation frequency of the battery thermal management system (BTMS), and lowering overall vehicle energy consumption. Specific thermal conductivity matching helps to achieve a uniform temperature distribution within the battery module, reducing temperature differences between individual cells, improving battery pack consistency, and extending battery cycle life. Appropriate thermal conductivity also prevents excessively low component surface temperatures, avoiding condensation on component surfaces in humid environments and preventing electrical short-circuit risks.

[0013] In some embodiments, the density of the first protective layer is 250 kg / m³. 3 ~400kg / m 3 ; and / or, The density of the second protective layer is 150 kg / m³ 3 ~250kg / m 3 ; and / or, The density of the third protective layer is 80 kg / m³. 3 ~150kg / m 3 .

[0014] The first protective layer has a higher density (250~400kg / m³), while the third protective layer has a lower density (80~150kg / m³). This overall density gradient design balances lightweight construction with protective performance, resulting in significant weight reduction compared to traditional structures at the same protection level, directly improving the vehicle's driving range. The low-density layer's excellent flexibility allows for fitting to irregularly shaped curved surfaces, reducing installation stress. Simultaneously, the low-density porous structure has energy absorption and shock absorption properties, absorbing the minute deformation stress generated by battery expansion during charging and discharging, protecting the cells from mechanical damage. The low-density material occupies less space, helping to increase the volumetric energy density of the battery pack, allowing for more cells to be installed within a limited space. Lightweight components facilitate manual or robotic installation, reducing the labor intensity of production line workers and improving assembly efficiency. The porous low-density material has sound-absorbing properties, helping to reduce noise transmission within the battery pack and improving the overall vehicle's sound insulation performance.

[0015] In some embodiments, the thickness ratio of the first, second, and third protective layers is 1:(3~7):(0.5~2). This allows for functional partitioning, forming a dense, heat-resistant section on the hot side, a gradient heat-insulating section in the middle (thickest, the main heat-insulating area), and a flexible, low-thermal-conductivity section on the cold side. This achieves graded protection, maximizes material performance utilization, and avoids material waste or insufficient performance. The overall thickness is controlled within a reasonable range (2.5mm~5mm), reducing space occupation and adapting to the high energy density development needs of battery packs. This avoids excessive occupation of valuable internal space by protective components, facilitating vehicle layout. The thicker middle layer provides the main heat capacity, absorbing sudden heat and preventing excessively high instantaneous temperature peaks, thus providing a valuable time window for the active cooling system to activate and offering crucial rescue time. The reasonable thickness ratio ensures that the components are not easily bent or deformed, maintaining shape stability even under long-term vibration environments and preventing frictional loss with the battery cells.

[0016] In some embodiments, the diameter of the microchannel is 0.5mm to 2mm. It should be noted that the microchannel diameter is less than half the overall thickness of the first, second, and third protective layers to ensure sufficient protective layer material on both the upper and lower sides of the microchannel to provide fire resistance, heat insulation, and support performance. When the overall thickness of the component is in the small range of 2.5mm to 3mm, the microchannel diameter is preferably controlled to be 0.5mm to 1.2mm; when the overall thickness of the component increases to more than 3mm, a larger diameter microchannel can be used, not exceeding 2mm, and always ensuring that the microchannel diameter is less than half the overall thickness of the component; and / or, The microchannels adopt a distributed or labyrinthine uniform layout. The channels are embedded inside the three protective layers of the power battery heat insulation and protection component. The microchannel walls are integrally formed with the three protective layers of the same material. Fluid interfaces are reserved at both ends of the microchannels to connect to the external fluid storage and supply unit.

[0017] Distributed or labyrinthine uniform layouts can adapt to the uniform heat exchange and fire suppression requirements of modules of different sizes, reducing cooling dead zones and achieving rapid cooling, flame retardancy, and suffocation fire suppression, eliminating localized hot spots within the battery pack. The microchannel diameter is adaptable to various protective media such as coolant, flame-retardant gel, and inert gas, enabling multi-media synergistic cooling and fire suppression. Different media can be selected based on the level of thermal runaway; coolant is used initially, while gel or gas is used in severe cases, offering flexible strategies. Pre-installed fluid interfaces allow for quick plug-and-play connections between components and external pipelines, facilitating later maintenance, replacement, or repair without damaging the overall battery pack structure, thus reducing total lifecycle maintenance costs.

[0018] In some embodiments, the power battery thermal insulation protection component integrates a temperature sensor and / or a pressure sensor. The sensors are embedded within the power battery thermal insulation protection component and in the gaps between battery modules, used to collect real-time temperature and pressure data inside the battery pack. The system has a preset trigger threshold of: Temperature threshold 120℃~180℃; and / or, Pressure threshold: 0.2 MPa to 0.4 MPa.

[0019] Employing dual-parameter over-limit triggering logic based on temperature and pressure, this system can accurately capture the precursory characteristics of sudden pressure increases and gradual temperature rises in the early stages of thermal runaway. Compared to single-temperature monitoring, it can detect hidden faults such as internal short circuits earlier, allowing for proactive cooling and protection, thus preventing thermal runaway in its nascent stage. Compared to traditional single-temperature triggering structures, it offers faster response speeds and higher protection accuracy, effectively compensating for the lag in response of single-trigger methods, significantly improving battery thermal safety redundancy, reducing false alarm rates, and avoiding unnecessary waste of extinguishing agents. Embedded installation collects data in real time, enabling intelligent prediction of thermal runaway precursors and providing decision-making support for the battery management system. Simultaneously, it records pre-accident data for easy post-accident analysis and liability determination. The sensors are protected within the components, preventing damage from external mechanical impacts, water intrusion, and corrosion, ensuring the long-term accuracy and reliability of the monitoring data. The specific threshold range matches the thermal runaway initiation characteristics of lithium batteries, enabling protective measures to be activated before irreversible thermal runaway occurs. It is neither too sensitive to cause false triggering nor too sluggish to cause failure. It perfectly adapts to the chemical characteristics of mainstream lithium-ion batteries. The preset threshold can directly link with the BMS or fire protection system to achieve millisecond-level automatic response without manual intervention, ensuring safe protection even in unattended conditions, such as charging at night.

[0020] Secondly, this application provides a battery cell assembly, including a battery cell and a power battery thermal insulation protection assembly as described in the first aspect, disposed on the outer surface of the battery cell, wherein the third protective layer is tightly attached to the battery cell. The cold side of the protection assembly (the low thermal conductivity flexible third protective layer) is tightly attached to the battery cell, eliminating assembly gaps, preventing thermal short circuits caused by air gaps, reducing contact thermal resistance, ensuring maximum thermal insulation performance, and facilitating heat transfer from the battery cell to the assembly when heat dissipation is required. No additional adhesives or rivets are needed for fixing; the assembly relies on the material's own friction and flexible adhesion, protecting surrounding battery cells from chain ignition, simplifying the assembly process, reducing the number of fasteners, and lowering BOM costs. The tight attachment provides a certain constraint on the volume expansion of the battery cell during charging and discharging, reducing excessive expansion that could damage the internal structure and extending the battery cell's cycle life.

[0021] Thirdly, this application provides an electrical device including the battery cell assembly described in the second aspect. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Currently, new energy vehicle power batteries are rapidly developing towards high-rate fast charging, high energy density, and integrated modules. These batteries have wide operating temperature ranges, rapid heat accumulation during charging and discharging, fast thermal runaway trigger speeds, high flame jet temperatures, and intense heat spread, placing extremely high demands on the comprehensive performance of battery protection materials and structures. Existing power battery thermal protection technologies are mainly divided into two categories: purely passive thermal insulation protection and purely active cooling and fire extinguishing protection. These technologies have significant shortcomings and cannot simultaneously meet the integrated protection requirements of long-term thermal insulation, extreme resistance to high-temperature shocks, and dynamic intelligent fire extinguishing. Existing passive thermal insulation solutions mostly use homogeneous materials such as homogeneous basalt fiber and ordinary aerogel composite panels, which have uniform overall composition, density, and thermal conductivity. Under long-term thermal cycling and repeated thermal shock conditions of batteries, the internal thermal stress of homogeneous materials concentrates, making them prone to cracking, aerogel pulverization, and interface detachment, resulting in a significant degradation of long-term thermal insulation performance. At the same time, homogeneous materials cannot simultaneously achieve high-temperature shock resistance and ultra-low thermal conductivity, and cannot effectively block high-temperature flames and high-speed heat flow during high-temperature thermal runaway, thus having limited thermal blocking capabilities. Existing active fire suppression and cooling solutions mostly employ externally sewn piping, interlayered water hoses, split-type sprinkler structures, or pure homogeneous basalt fiber channel structures. These structures have significant drawbacks: sewn / embedded piping has an independent interface with the substrate, leading to carbonization of the seams and failure of the adhesive layer at high temperatures, making it prone to pipe detachment and leakage; pure homogeneous basalt fiber channel structures have limited thermal insulation performance, resulting in significant heat accumulation at room temperature and under normal operating conditions, failing to achieve long-term thermal insulation, and only able to passively respond after thermal runaway is triggered, lacking sufficient proactive protection. Currently, there is no technical solution in the industry that can deeply integrate the basalt-aerogel continuous gradient passive thermal insulation structure with the substrate integrated microchannel active fire extinguishing and cooling structure. It is impossible to achieve integrated and synergistic protection of long-term thermal insulation at room temperature gradient, high-temperature impact resistance to thermal runaway, and intelligent active fire extinguishing triggered by temperature and pressure. There are industry technical pain points such as poor stability of passive protection, low reliability of active protection, and insufficient adaptability to all working conditions.

[0024] For example, a type of active fire-resistant, heat-insulating flexible fabric and its preparation method employ a sandwich structure. This fabric consists of a surface layer of silica-alumina fiber cloth and a bottom layer of aramid fiber cloth, with an intermediate layer of aramid fiber cloth coated with a flame-retardant coating. The coating is composed of magnesium hydroxide, ammonium polyphosphate, magnesium silicate, hollow silica microspheres, and silicon nitride, which react at high temperatures to generate a ceramic phase to insulate against heat and flames. However, the overall structure is a layered, homogeneous composite structure with uniform components and no continuous gradient transition. This makes it impossible to achieve graded protection with impact resistance on the hot side and low thermal conductivity on the cold side. Under thermal cycling, thermal stress concentrates, leading to interlayer delamination, performance degradation, and poor long-term stability. Relying solely on the surface flame-retardant coating for passive fire protection, without built-in microfluidic channels, it cannot achieve active spray cooling or continuous heat absorption for fire extinguishing. It only provides surface flame retardancy and cannot extinguish internal thermal runaway flames or prevent heat spread. Lacking dual-sensor monitoring of temperature and pressure and predictive logic, it cannot intervene in the early stages of thermal runaway, only passively withstanding high temperatures, resulting in strong lag in protection. It adopts multi-layer lamination and coating bonding molding, with many interlayer interfaces. Under vehicle vibration and high temperature alternating conditions, it is prone to cracking, delamination and detachment, and cannot adapt to the complex dynamic conditions of power batteries.

[0025] For example, a composite thermal insulation pad and its manufacturing process use basalt fiber needle-punched felt and orthosilicate composite. Through the preparation of aerogel precursor hydrolysate, impregnation of the substrate, and multiple drying processes, the permeability and gel content of the aerogel are controlled to form a nano-network structure, thereby improving the material's mechanical strength and thermal insulation performance. However, it lacks a continuous gradient design, making it unable to balance high-temperature impact resistance with ultra-low thermal conductivity at room temperature. Its thermal barrier and stress relief capabilities are insufficient. It only possesses purely passive static thermal insulation functions, lacking active cooling and spray fire extinguishing structures, and cannot actively intervene in thermal runaway. It only provides passive protection and lacks the ability to prevent thermal runaway. Its limited functionality makes it unsuitable for complex operating conditions such as vehicle-mounted dynamic vibration and extreme thermal runaway spray, resulting in significant limitations in protection scenarios.

[0026] Given the core shortcomings of traditional protective structures, such as the disconnect between heat insulation and fire extinguishing, stress cracking and pulverization, high-temperature leakage and detachment of split-type flow channels, delayed response to thermal runaway, and poor adaptability and durability under all operating conditions, there is a need to provide a gradient-insulated, built-in microchannel intelligent cooling and fire extinguishing component for power batteries. This component would achieve deep integration of gradient passive heat insulation, high-temperature thermal shock resistance, and temperature and pressure dual-triggered active cooling and fire extinguishing, constructing a new integrated, full-cycle, and highly reliable battery thermal safety protection system. This application provides a power battery heat insulation protection component, a cell assembly, and an electrical device to improve the shortcomings of poor stability in passive protection, low reliability in active protection, and insufficient adaptability under all operating conditions.

[0027] In a first aspect, this application provides a power battery heat insulation and protection component, which includes a first protective layer, a second protective layer, and a third protective layer sequentially disposed in its thickness direction, wherein: The materials of the power battery heat insulation protection component include ceramic fiber and aerogel; The volume percentage of ceramic fibers in the first, second, and third protective layers decreases progressively. The volume percentage of aerogel in the first, second, and third protective layers increases progressively. The first, second, and third protective layers are also provided with microchannels for fluid to pass through; The first protective layer, the second protective layer, and the third protective layer are integrally formed.

[0028] This application employs a continuous gradient structure with a gradually changing volume ratio of ceramic fiber and aerogel, utilizing the difference in the thermal expansion coefficients of the two materials to progressively release thermal stress generated by thermal cycling. This reduces the problems of thermal cycling cracking, pulverization and detachment, and performance degradation caused by thermal stress concentration in traditional homogeneous structures, significantly extending the lifespan of the module and ensuring that the protective performance does not degrade throughout the entire battery life cycle. The microchannels and gradient substrate are integrally molded, eliminating the bonding or sewing interfaces between the traditional separate channels and the insulation layer. This solves the problems of channel detachment and leakage failure caused by adhesive carbonization and seam melting at high temperatures in traditional structures. At the same time, the tight connection reduces interlayer contact thermal resistance, allowing heat to be smoothly transferred from the high-temperature side to the microchannels and carried away, improving structural integrity and protective reliability under extreme thermal runaway conditions. A gradient insulation layer provides passive insulation under normal conditions, while microchannels provide active cooling / fire suppression under extreme conditions. This achieves full-cycle synergistic protection through passive insulation to prevent heat accumulation under normal conditions, intelligent pre-emptive control to prevent runaway, and active fire suppression to prevent the spread of heat. It covers the safety needs of the entire battery lifecycle and solves the problems of insufficient passive insulation to cope with thermal runaway and high energy consumption of active cooling alone. A high-fiber-content first protective layer blocks the intrusion of external high temperatures, while a high-aerogel-content third protective layer blocks the outward transfer of internal heat. Microchannels rapidly remove heat in the middle layer, achieving a two-way thermal management balance. This prevents both external fire sources from igniting the battery and internal overheating from igniting external sources, forming a two-way safety barrier. The three layers are tightly connected to form a single component, improving the overall mechanical strength of the module and enabling it to withstand vibrations and impacts within the battery pack, preventing displacement or loosening of the module during vehicle operation.

[0029] In conjunction with the first aspect, in some embodiments provided in this application, the ceramic fiber includes at least one of basalt fiber, alumina fiber, quartz fiber, and aluminosilicate fiber.

[0030] The aerogel includes at least one of silica aerogel, alumina aerogel, and zirconia aerogel.

[0031] Both the ceramic fiber and aerogel materials mentioned above have excellent resistance to electrolyte corrosion. They do not swell or decompose under battery leakage conditions, maintain stable protective performance, and reduce safety hazards caused by material failure. Basalt fiber possesses ultra-high temperature resistance, capable of withstanding instantaneous high-temperature jets exceeding 800°C, and exhibits excellent resistance to flame impact and thermal radiation. It can serve as a skeletal support to prevent components from being ablated and perforated during thermal runaway, ensuring structural stability under the impact of flame jets from the battery. Alumina aerogel and zirconia aerogel can further enhance the high-temperature resistance to an upper limit of 1000°C, making it suitable for extreme high heat flux density conditions.

[0032] Silica aerogel possesses a nanoporous structure and extremely low thermal conductivity, enabling long-lasting thermal insulation at room temperature. It effectively blocks heat transfer to the battery body, reducing heat accumulation caused by high ambient temperatures or thermal runaway from adjacent batteries, thus lowering air conditioning energy consumption. Alumina fibers and quartz fibers can enhance the ablation resistance and thermal shock resistance of the hot side.

[0033] In conjunction with the first aspect, in some embodiments provided in this application, the volume percentage of ceramic fibers in the first protective layer is 60% to 80%. This high fiber percentage in the first protective layer (hot side) can form a dense, high-temperature resistant barrier, possessing high-temperature resistance and flame impact resistance, reducing the probability of the substrate being ablated and perforated by high-temperature gas flow in the early stages of thermal runaway, thus ensuring the first line of defense does not fail. The volume percentage of ceramic fibers in the first protective layer includes, but is not limited to, 60%, 62.5%, 65%, 67.5%, 70%, 72.5%, 75%, 77.5%, or 80%.

[0034] The volume percentage of ceramic fibers in the second protective layer is 20% to 60%. Specifically, the volume percentage of ceramic fibers in the second protective layer can gradually change from 40% to 60% near the first protective layer to 20% to 40% near the third protective layer. The composition of the second protective layer (middle layer) changes continuously and gradually, releasing heat flow step by step through a continuous gradient impedance. This not only blocks heat transfer but also mitigates thermal cycling stress, reducing delamination between layers due to abrupt material changes. This ensures that the three-layer structure does not delaminate during long-term use, reducing cracking and differentiation. The volume percentage of ceramic fibers in the second protective layer includes, but is not limited to, a gradual change from 60% to 40%, from 55% to 35%, from 50% to 30%, from 45% to 25%, and from 40% to 20%.

[0035] The ceramic fiber volume fraction in the third protective layer is 10% to 20%. This third protective layer (cold side) has a high aerogel content, excellent thermal conductivity and flexibility, allowing it to tightly conform to the irregular curved surfaces of the battery module, eliminating assembly gaps, reducing the risk of thermal short circuits caused by gaps, and minimizing thermal insulation dead zones. The ceramic fiber volume fraction in the second protective layer includes, but is not limited to, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0036] A higher fiber content results in higher strength, while a higher aerogel content results in better flexibility. This achieves a smooth transition in mechanical properties from high-strength support on the hot side to flexible buffering on the cold side, protecting the battery from impacts by hard objects while also preventing damage to the battery casing from hard contact.

[0037] In conjunction with the first aspect, in some embodiments provided in this application, the thermal conductivity of the first protective layer at 25°C is 0.025 W / (m·K) to 0.035 W / (m·K). The thermal conductivity of the first protective layer at 25°C includes, but is not limited to, 0.025 W / (m·K), 0.026 W / (m·K), 0.027 W / (m·K), 0.028 W / (m·K), 0.029 W / (m·K), 0.030 W / (m·K), 0.031 W / (m·K), 0.032 W / (m·K), 0.033 W / (m·K), 0.034 W / (m·K), or 0.035 W / (m·K).

[0038] The thermal conductivity of the second protective layer at 25°C is 0.018 W / (m·K) to 0.025 W / (m·K). The thermal conductivity of the second protective layer at 25°C includes, but is not limited to, 0.018 W / (m·K), 0.019 W / (m·K), 0.020 W / (m·K), 0.021 W / (m·K), 0.022 W / (m·K), 0.023 W / (m·K), 0.024 W / (m·K), or 0.025 W / (m·K).

[0039] The thermal conductivity of the third protective layer at 25°C is 0.012 W / (m·K) to 0.018 W / (m·K). The thermal conductivity of the third protective layer at 25°C includes, but is not limited to, 0.012 W / (m·K), 0.013 W / (m·K), 0.014 W / (m·K), 0.015 W / (m·K), 0.016 W / (m·K), 0.017 W / (m·K), or 0.018 W / (m·K).

[0040] Through a gradient thermal conductivity design, with the first to third protective layers decreasing in thermal conductivity, heat flow is gradually consumed and attenuated during transfer, effectively blocking heat transfer to the battery body, reducing the battery temperature rise rate, and providing more reaction time for the thermal management system. The ultra-low thermal conductivity on the cold side (0.012 W / (m·K) ~ 0.018 W / (m·K)) enables long-lasting insulation at room temperature, preventing battery aging due to excessive environmental temperature differences and heat accumulation, ensuring the battery operates within a suitable temperature window, reducing the activation frequency of the battery thermal management system (BTMS), and lowering overall vehicle energy consumption. Specific thermal conductivity matching helps to achieve a uniform temperature distribution within the battery module, reducing temperature differences between individual cells, improving battery pack consistency, and extending battery cycle life. Appropriate thermal conductivity also prevents excessively low component surface temperatures, avoiding condensation on component surfaces in humid environments and preventing electrical short-circuit risks.

[0041] In conjunction with the first aspect, in some embodiments provided in this application, the density of the first protective layer is 250 kg / m³. 3 ~400kg / m 3 The density of the first protective layer includes, but is not limited to, 250 kg / m³. 3 275kg / m 3 300kg / m 3 320kg / m 3 350kg / m 3 375kg / m 3 Or 400kg / m 3 .

[0042] The density of the second protective layer is 150 kg / m³ 3 ~250kg / m 3 The density of the second protective layer includes, but is not limited to, 150 kg / m³. 3 175kg / m 3 200kg / m 3 220kg / m 3 Or 250kg / m 3 .

[0043] The density of the third protective layer is 80 kg / m³. 3 ~150kg / m 3 The density of the third protective layer includes, but is not limited to, 80 kg / m³. 3 90kg / m 3 100kg / m 3 110kg / m 3 120kg / m 3 130kg / m 3 140kg / m 3Or 150kg / m 3 .

[0044] The first protective layer has a higher density (250~400kg / m³), while the third protective layer has a lower density (80~150kg / m³). This overall density gradient design balances lightweight construction with protective performance, resulting in significant weight reduction compared to traditional structures at the same protection level, directly improving the vehicle's driving range. The low-density layer's excellent flexibility allows for fitting to irregularly shaped curved surfaces, reducing installation stress. Simultaneously, the low-density porous structure has energy absorption and shock absorption properties, absorbing the minute deformation stress generated by battery expansion during charging and discharging, protecting the cells from mechanical damage. The low-density material occupies less space, helping to increase the volumetric energy density of the battery pack, allowing for more cells to be installed within a limited space. Lightweight components facilitate manual or robotic installation, reducing the labor intensity of production line workers and improving assembly efficiency. The porous low-density material has sound-absorbing properties, helping to reduce noise transmission within the battery pack and improving the overall vehicle's sound insulation performance.

[0045] In conjunction with the first aspect, in some embodiments provided in this application, the thickness ratio of the first protective layer, the second protective layer, and the third protective layer is 1:(3~7):(0.5~2). This allows for the formation of functional zones: a dense, heat-resistant section on the hot side, a gradient heat-insulating section in the middle (the thickest, the main heat-insulating area), and a flexible, low-thermal-conductivity section on the cold side. This achieves graded protection, maximizes material performance utilization, and avoids material waste or insufficient performance. The overall thickness is controlled within a reasonable range (2.5mm~5mm), reducing space occupation and adapting to the high energy density development needs of battery packs. This avoids excessive occupation of valuable internal space by protective components, facilitating vehicle layout. The thicker middle layer provides the main heat capacity, absorbing sudden heat and preventing excessively high instantaneous temperature peaks, thus providing a valuable time window for the active cooling system to activate and offering crucial rescue time. The reasonable thickness ratio ensures that the components are not easily bent or deformed, maintaining shape stability even under long-term vibration environments and preventing frictional loss with the battery cells. The thickness ratio of the first protective layer, the second protective layer and the third protective layer includes, but is not limited to, 1:3:0.5, 1:3:2, 1:4:0.5, 1:4:2, 1:7:0.5, 1:7:2 or 1:4:1.

[0046] In conjunction with the first aspect, in some embodiments provided in this application, the diameter of the microchannel is 0.5mm to 2mm. It should be noted that the microchannel diameter is less than half the overall thickness of the first, second, and third protective layers to ensure that both the upper and lower sides of the microchannel retain sufficient protective layer material to provide fireproof, heat-insulating, and support performance. When the overall thickness of the component is in the relatively small range of 2.5mm to 3mm, the microchannel diameter is preferably controlled to be 0.5mm to 1.2mm; when the overall thickness of the component increases to more than 3mm, a larger diameter microchannel can be selected, not exceeding 2mm, and always ensuring that the microchannel diameter is less than half the overall thickness of the component.

[0047] The microchannels adopt a distributed or labyrinthine uniform layout. The channels are embedded inside the three protective layers of the power battery heat insulation and protection component. The microchannel walls are integrally formed with the three protective layers of the same material. Fluid interfaces are reserved at both ends of the microchannels to connect to the external fluid storage and supply unit.

[0048] Distributed or labyrinthine uniform layouts can adapt to the uniform heat exchange and fire suppression requirements of modules of different sizes, reducing cooling dead zones and achieving rapid cooling, flame retardancy, and suffocation fire suppression, eliminating localized hot spots within the battery pack. The microchannel diameter is adaptable to various protective media such as coolant, flame-retardant gel, and inert gas, enabling multi-media synergistic cooling and fire suppression. Different media can be selected based on the level of thermal runaway; coolant is used initially, while gel or gas is used in severe cases, offering flexible strategies. Pre-installed fluid interfaces allow for quick plug-and-play connections between components and external pipelines, facilitating later maintenance, replacement, or repair without damaging the overall battery pack structure, thus reducing total lifecycle maintenance costs.

[0049] In conjunction with the first aspect, in some embodiments provided in this application, the power battery heat insulation protection component integrates a temperature sensor and / or a pressure sensor. The sensors are embedded within the power battery heat insulation protection component and in the gaps between battery modules, used to collect real-time temperature and pressure data inside the battery pack. The system has preset trigger thresholds of: a temperature threshold of 120℃~180℃ and a pressure threshold of 0.2MPa~0.4MPa. The temperature thresholds include, but are not limited to, 120℃, 130℃, 140℃, 150℃, 155℃, 160℃, 170℃, or 180℃. The pressure thresholds include, but are not limited to, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, or 0.4MPa.

[0050] Employing dual-parameter over-limit triggering logic based on temperature and pressure, this system can accurately capture the precursory characteristics of sudden pressure increases and gradual temperature rises in the early stages of thermal runaway. Compared to single-temperature monitoring, it can detect hidden faults such as internal short circuits earlier, allowing for proactive cooling and protection, thus preventing thermal runaway in its nascent stage. Compared to traditional single-temperature triggering structures, it offers faster response speeds and higher protection accuracy, effectively compensating for the lag in response of single-trigger methods, significantly improving battery thermal safety redundancy, reducing false alarm rates, and avoiding unnecessary waste of extinguishing agents. Embedded installation allows for real-time data acquisition, enabling intelligent prediction of thermal runaway precursors and providing decision-making support for the BMS system. Simultaneously, it records pre-accident data for easy post-accident analysis and liability determination. The sensors are protected internally, preventing damage from external mechanical impacts, water intrusion, and corrosion, ensuring the long-term accuracy and reliability of the monitoring data. The specific threshold range matches the thermal runaway initiation characteristics of lithium batteries, enabling protective measures to be activated before irreversible thermal runaway occurs. It is neither too sensitive to cause false triggering nor too sluggish to cause failure. It perfectly adapts to the chemical characteristics of mainstream lithium-ion batteries. The preset threshold can directly link with the BMS or fire protection system to achieve millisecond-level automatic response without manual intervention, ensuring safe protection even in unattended conditions, such as charging at night.

[0051] It should be noted that the power battery heat insulation protection component of this application can be prepared by a removable sacrificial template integral molding process.

[0052] 1) Prepare gradient slurry: Prepare basalt fiber-aerogel precursor slurries for the hot side, intermediate gradient section, and cold side respectively. The fiber and aerogel precursor ratios of each slurry section are continuously adjusted from the hot side to the cold side according to the gradient components. 2) Placement of sacrificial template: Inside the molding die, sacrificial filament templates that can be thermally decomposed / solventized are arranged according to a preset labyrinthine flow channel layout; the sacrificial filament material can be polyvinyl alcohol (PVA) or polylactic acid (PLA), and the filament diameter corresponds to the target microchannel diameter of 0.5mm~1.5mm; the sacrificial filaments are positioned and fixed as a whole and do not shift; 3) Gradient step-by-step grouting: Grout is continuously injected into the mold from the hot side to the cold side, and the grout is laid layer by layer to achieve a smooth transition in fiber-aerogel components and density, and to completely encapsulate the sacrificial template inside the grout matrix. 4) Curing and aging: Constant temperature curing and solvent replacement in a closed environment to obtain a gradient composite preform coated with a sacrificial template; 5) Template removal: The billet is heat-treated at a temperature of 180℃~260℃ to thermally decompose and volatilize the internal sacrificial wire, leaving a continuous labyrinthine microchannel in situ inside the matrix. 6) Post-processing: hydrophobic modification, cutting, and reserving flow channel interfaces to obtain a protective component with an integrated microchannel built into the gradient substrate.

[0053] Secondly, this application provides a battery cell assembly, including a battery cell and a power battery thermal insulation protection assembly as described in the first aspect, disposed on the outer surface of the battery cell, wherein the third protective layer is tightly attached to the battery cell. The cold side of the protection assembly (the low thermal conductivity flexible third protective layer) is tightly attached to the battery cell, eliminating assembly gaps, preventing thermal short circuits caused by air gaps, reducing contact thermal resistance, ensuring maximum thermal insulation performance, and facilitating heat transfer from the battery cell to the assembly when heat dissipation is required. No additional adhesives or rivets are needed for fixing; the assembly relies on the material's own friction and flexible adhesion, protecting surrounding battery cells from chain ignition, simplifying the assembly process, reducing the number of fasteners, and lowering BOM costs. The tight attachment provides a certain constraint on the volume expansion of the battery cell during charging and discharging, reducing excessive expansion that could damage the internal structure and extending the battery cell's cycle life.

[0054] Thirdly, this application provides an electrical device including the battery cell assembly described in the second aspect.

[0055] The power battery thermal insulation protection component of this application can be adapted to the complex on-board conditions of power battery modules and sealed PACK packs in new energy passenger vehicles and commercial vehicles. It adopts a standardized bonding and installation method: the cold side of the third protective layer of the substrate (low thermal conductivity flexible layer) is tightly bonded to the outer surface of the battery cell and module, eliminating assembly gaps and preventing thermal short circuits; the hot side of the first protective layer (high temperature resistant dense layer) faces the battery pack cavity, wiring harness and surrounding structure, resisting external heat radiation and high-temperature flames ejected from the cell during thermal runaway. It can flexibly adapt to various assembly forms such as full coverage of the module, cell spacing thermal insulation and flame retardancy, and bottom / top / side protection of the PACK. The component as a whole has excellent bending performance and vibration resistance performance, requiring no additional adhesives or rivets for fixing. It can be adapted to the bonding and installation of irregularly shaped curved modules and is suitable for harsh working environments such as long-term bumpy driving, high and low temperature alternation (-40℃~600℃), and electrolyte corrosion.

[0056] The working principle is to achieve thermal safety protection throughout the entire battery life cycle through the coordinated operation of graded thermal insulation using gradient substrates and active medium spraying via microchannels. 1) Normal operating conditions: The small amount of heat generated during normal charging and discharging of the battery is gradually dissipated through the multi-level thermal resistance of the gradient substrate. The ultra-low thermal conductivity layer on the cold side blocks the heat accumulation, achieving long-term passive heat insulation and avoiding excessive temperature difference and heat accumulation aging of the battery. 2) Precursor conditions for thermal runaway: The internal pressure of the battery rises first or the temperature continues to rise. The embedded sensor captures abnormal parameters in real time, triggers the intelligent control unit, and starts fluid pre-cooling in advance to suppress the continuous rise of the cell temperature and block thermal runaway in the early stage. 3) Extreme thermal runaway conditions: When the cell experiences thermal runaway and ejects high-temperature flames and high heat flow, the dense heat-resistant layer on the hot side instantly resists the impact of high temperatures above 800°C, preventing the substrate from burning and failing. At the same time, the microchannels rapidly release protective media throughout the entire area, which quickly extinguishes open flames and blocks the spread of heat through multiple effects such as cooling, suffocation, and flame retardancy, protecting the surrounding cells from being ignited by a chain reaction.

[0057] The following description, based on specific assembly conditions, parameter ratios, and measured data, serves as an example to illustrate this application and is intended only to explain the application and does not limit the scope of protection of this application.

[0058] This product is applied to standard ternary lithium battery modules for new energy passenger vehicles. The battery module has a rated voltage of 400V and a single module capacity of 50Ah, making it a mainstream high-energy-density power battery module in the industry. It is characterized by rapid thermal runaway and a high risk of thermal propagation. The overall thickness of the power battery thermal insulation protection component is set at 2.5mm. The first protective layer, a dense, heat-resistant section on the hot side, is 0.375mm thick, accounting for 15% of the total thickness. The second protective layer, a gradient thermal insulation section in the middle, is 1.75mm thick, accounting for 70% of the total thickness. The third protective layer, a flexible, low-thermal-conductivity section on the cold side, is also 0.375mm thick, accounting for 15% of the total thickness. After deducting the microfluidic cavity, the first protective layer of the dense, heat-resistant section on the hot side is made of basalt fiber, with a basalt fiber volume fraction of 70% and a silica aerogel volume fraction of 30%; its density is 320kg / m³. 3 Thermal conductivity at room temperature is 0.030 W / (m²). K); Second protective layer of intermediate gradient insulation section: basalt fiber volume fraction gradually and smoothly changes from 55% to 25%, silica aerogel volume fraction gradually and smoothly changes from 45% to 75%; density 220 kg / m³ 3 The thermal conductivity at room temperature is 0.022 W / (m). K); Cold-side flexible low thermal conductivity section third protective layer: basalt fiber volume fraction 15%, silica aerogel volume fraction 85%; density 110kg / m³ 3 The thermal conductivity at room temperature is 0.015 W / (m²). K). It is suitable for the narrow installation space of mainstream battery packs. The overall structure adopts a basalt-aerogel continuous gradient composite substrate + built-in labyrinth microchannel structure. The microchannel diameter is 1mm and it is uniformly embedded in the gradient substrate. The protective medium is pure water-based flame retardant coolant. The trigger threshold is set as follows: temperature 150℃, pressure 0.3MPa. Active protection will be activated immediately if any parameter exceeds the limit.

[0059] The power battery thermal insulation protection component is completely wrapped around the outer surface of the power battery module. It adopts an installation method in which the cold side of the third protective layer is bonded to the battery module and the hot side of the first protective layer faces the battery pack cavity. There are no adhesives or rivets for fixing. It relies on its own flexibility to fit the irregular curved surface of the module, which is fully adapted to the vehicle vibration conditions. The interfaces at both ends of the microchannel are sealed and connected to the external small liquid storage tank and the electronic control valve. Sensors are embedded in the gaps between the modules and inside the substrate to collect temperature and pressure data in real time.

[0060] The measured working conditions and effect data are as follows: Normal charge and discharge steady-state operating conditions (-20℃~45℃) The battery can continuously cycle through 1C fast charging and discharging for 500 hours. The protective components rely on a gradient multi-level heat insulation structure to effectively suppress battery heat accumulation. The maximum temperature difference of the battery module is controlled within 3℃, with no local overheating or temperature drift. The substrate is free from cracking, powdering, and peeling, and the heat insulation performance is not degraded, making it perfectly suitable for daily driving and frequent charging and discharging conditions of vehicles.

[0061] Intervention conditions for early signs of thermal runaway Artificially simulating localized overheating of the battery cell, the module temperature rapidly rose to 152℃ and the internal pressure rose to 0.32MPa, triggering the dual-trigger protection mechanism; coolant water was rapidly sprayed throughout the microchannels, and cooling began within 3 seconds. Within 20 seconds, the module temperature dropped from 152℃ to below 80℃, and the pressure quickly returned to a safe range, successfully preventing the onset of thermal runaway and showing no trend of heat spread.

[0062] Extreme thermal runaway injection conditions Simulating thermal runaway and deflagration of a battery cell, the instantaneous spray temperature reached as high as 780℃. The dense, heat-resistant section on the hot side continuously resisted the impact of the high-temperature flame, and the substrate showed no ablation, perforation, or structural damage. At the same time, the microchannel continuously released flame-retardant coolant, which quickly absorbed heat, cooled down, and suffocated the fire, extinguishing the open flame within 10 seconds. It completely blocked the spread of high-temperature heat flow to surrounding battery cells, and the temperature of adjacent battery cells was always controlled below 180℃. No chain thermal runaway occurred, and the protection effect was excellent.

[0063] In summary, this application constructs a full-cycle collaborative protection system encompassing passive thermal insulation to prevent heat accumulation under normal conditions, intelligent pre-control to prevent runaway, and active fire suppression to prevent fire spread in extreme conditions. The gradient structure mitigates thermal stress, significantly improving long-term protection stability. The four-dimensional continuous interface-free gradient structure progressively mitigates thermal stress generated by thermal cycles, addressing industry pain points such as stress concentration, cracking, pulverization, and performance degradation inherent in traditional homogeneous protective materials. It also balances the dual performance of high-temperature flame impact resistance on the hot side and ultra-low thermal conductivity insulation on the cold side, adapting to stable protection under long-term alternating battery operating conditions. The homogeneous integrated flow channel structure mitigates high-temperature failure risks. The microchannels and gradient substrate are integrally molded simultaneously, eliminating post-sewing, bonding, and embedding interfaces, avoiding the high-temperature carbonization, detachment, and leakage failures of traditional split flow channels, and significantly improving the reliability and structural integrity of protection under extreme thermal runaway conditions. With intelligent dual-parameter triggering for temperature and pressure, thermal runaway intervention is more precise and timely. Employing dual-parameter over-limit triggering logic, it accurately captures the precursory characteristics of sudden pressure increases and gradual temperature rises in the early stages of thermal runaway, intervening early for cooling and protection. This effectively compensates for the lag in response of single triggering methods, significantly improving battery thermal safety redundancy. It is compatible with various protective media such as liquid coolant, flame-retardant gel, and inert gas, adapting to different operating conditions including conventional heat dissipation, thermal runaway cooling, and open flame extinguishing. The overall structure is vibration-resistant, resistant to alternating high and low temperatures, and resistant to electrolyte corrosion. No additional fixing is required, and it can flexibly fit irregularly shaped battery modules, perfectly adapting to the harsh operating conditions of new energy vehicles. The integrated composite structure eliminates the need for multiple layers of protective structures, with an overall thickness controlled between 2.5mm and 5mm. Compared to traditional multi-layer composite protective structures, it significantly reduces weight and space occupation at the same protection level, balancing high protection performance with lightweight advantages, aligning with the industry trend of high integration and high energy density in power batteries.

[0064] The terms "comprising" and "having," and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or device. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0065] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0066] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0067] The above are merely preferred embodiments of this application and do not limit the scope of this application. Any equivalent structural or procedural changes made using the content of this application’s specification, or any direct or indirect application in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A power battery heat insulation and protection component, characterized in that, It includes a first protective layer, a second protective layer, and a third protective layer arranged sequentially in its thickness direction, wherein: The materials of the power battery heat insulation protection component include ceramic fiber and aerogel; The volume percentage of ceramic fibers in the first, second, and third protective layers decreases progressively. The volume percentage of aerogel in the first, second, and third protective layers increases progressively. The first, second, and third protective layers are also provided with microchannels for fluid to pass through; The first protective layer, the second protective layer, and the third protective layer are integrally formed.

2. The power battery heat insulation and protection component as described in claim 1, characterized in that: The ceramic fiber includes at least one of basalt fiber, alumina fiber, quartz fiber, and aluminosilicate fiber; and / or, The aerogel includes at least one of silica aerogel, alumina aerogel, and zirconia aerogel.

3. The power battery heat insulation and protection component as described in claim 1, characterized in that: The ceramic fiber volume fraction in the first protective layer is 60%~80%; and / or, The ceramic fiber volume fraction in the second protective layer is 20% to 60%; and / or, The volume percentage of ceramic fiber in the third protective layer is 10% to 20%.

4. The power battery heat insulation and protection component as described in claim 1, characterized in that: The thermal conductivity of the first protective layer at 25°C is 0.025 W / (m·K) ~ 0.035 W / (m·K); and / or, The second protective layer has a thermal conductivity of 0.018 W / (m·K) to 0.025 W / (m·K) at 25°C; and / or, The thermal conductivity of the third protective layer at 25°C is 0.012 W / (m·K) to 0.018 W / (m·K).

5. The power battery heat insulation and protection component as described in claim 1, characterized in that: The density of the first protective layer is 250 kg / m³ 3 ~400kg / m 3 ; and / or, The density of the second protective layer is 150 kg / m³ 3 ~250kg / m 3 ; and / or, The density of the third protective layer is 80 kg / m³. 3 ~150kg / m 3 .

6. The power battery heat insulation and protection component as described in claim 1, characterized in that: The thickness ratio of the first protective layer, the second protective layer and the third protective layer is 1:(3~7):(0.5~2).

7. The power battery heat insulation and protection component as described in claim 1, characterized in that: The diameter of the microchannel is 0.5 mm to 2 mm; and / or, The microchannels adopt a distributed or labyrinthine uniform layout. The channels are embedded inside the three protective layers of the power battery heat insulation and protection component. The microchannel walls are integrally formed with the three protective layers of the same material. Fluid interfaces are reserved at both ends of the microchannels to connect to the external fluid storage and supply unit.

8. The power battery heat insulation and protection component as described in claim 1, characterized in that, The power battery thermal insulation protection component integrates a temperature sensor and / or a pressure sensor. The sensor is embedded in the power battery thermal insulation protection component and the gap between the battery modules to collect real-time temperature and pressure data inside the battery pack.

9. A battery cell assembly, characterized in that, The battery includes a battery cell and a power battery heat insulation protection assembly as described in any one of claims 1 to 8, wherein the third protective layer is disposed in close contact with the battery cell.

10. An electrical appliance, characterized in that, Includes the cell assembly as described in claim 9.