Lithium ion battery thermal management and thermal runaway blocking device and system design optimization method based on novel inorganic phase change material

Abstract

The invention provides a lithium ion battery thermal management and thermal runaway blocking device and system design optimization method based on a novel inorganic phase change material, and belongs to the technical field of lithium ion battery thermal safety. The lithium ion battery thermal management and thermal runaway blocking device based on the novel inorganic phase change material comprises a slidable support base, a lithium battery, a heat absorption and insulation layer and temperature sensing monitoring equipment, the slidable support base comprises a sliding rail base and a plurality of detachable positioning plates, and the detachable positioning plates are clamped on the sliding rail base; the heat absorption and heat insulation layer is used for fixing the lithium battery, the interval can be flexibly adjusted according to different sizes of the lithium battery and the heat absorption and heat insulation layer, and the heat absorption and heat insulation layer is suitable for lithium ion battery packs with various battery shapes and different chemical systems; the problem of heat accumulation caused by charging and discharging during normal working of the lithium ion battery can be solved, and the potential safety hazard that fire spreading is aggravated due to flammability of a traditional organic phase change material when thermal runaway occurs can be solved.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery thermal safety technology. Specifically, it relates to a design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device and system based on a novel inorganic phase change material. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, portable electronic devices, and large-scale energy storage due to their high energy density and long cycle life. However, batteries are prone to thermal runaway under abuse conditions such as overcharging, short circuits, and overheating. This leads to a rapid increase in temperature, internal gas production and pressurization, and ultimately, jet fires or even explosions, seriously threatening life and property safety. Especially in modules composed of multiple cells, thermal runaway of a single cell can rapidly spread to the entire system, causing a catastrophic chain reaction. To manage battery temperature and improve safety, phase change materials (PCMs) have been introduced into battery thermal management technology due to their excellent latent heat storage and temperature regulation capabilities. Currently, widely used organic PCMs such as paraffin wax have good flexibility and chemical stability, but their inherent flammability poses a serious safety hazard. When a battery experiences thermal runaway, the high temperature and splashes can easily ignite the organic PCMs, turning them from a thermal management medium into a combustion accelerant, which in turn exacerbates the fire and heat spread, accelerating the propagation of thermal runaway.

[0003] To address the flammability issue, non-flammable inorganic phase change materials (such as hydrated salts and molten salts) have attracted researchers' attention. However, inorganic phase change materials themselves have significant drawbacks, including: 1) high rigidity and poor flexibility, making it difficult to fit onto battery surfaces of different shapes, and prone to gaps or even cracks under conditions such as vehicle vibration, leading to increased contact thermal resistance and decreased thermal management efficiency; 2) phase separation and supercooling issues affect their long-term cycling stability; 3) low intrinsic thermal conductivity, limiting their heat absorption and dissipation rates.

[0004] Existing technologies attempt to modify inorganic phase change materials, such as through porous framework encapsulation or the addition of thermally conductive fillers. However, these methods often struggle to balance safety, flexibility, thermal conductivity, and structural stability. For example, macroscopic encapsulation structures may increase interfacial thermal resistance, while simply enhancing thermal conductivity cannot address the flame-retardant and heat-insulating requirements of the material in thermal runaway scenarios. Furthermore, the design of thermal management devices for phase change materials relies heavily on experience, lacking systematic optimization methods, resulting in poor adaptability to batteries with different chemical systems and sizes.

[0005] Therefore, there is an urgent need in this field for an innovative solution that can develop a phase change material that is non-flammable, highly flexible, and has efficient thermal conductivity / insulation properties, and based on this, construct an intelligent device that integrates daily thermal management and thermal runaway prevention, while optimizing the solution and making it universally applicable through scientific design methods. Summary of the Invention

[0006] In view of this, the present invention provides a design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device and system based on a novel inorganic phase change material. This method can solve the problem of heat accumulation caused by charging and discharging during normal operation of lithium-ion batteries, as well as the safety hazard of exacerbating the spread of fire due to the flammability of traditional organic phase change materials when thermal runaway occurs.

[0007] This invention is implemented as follows:

[0008] The first aspect of this invention provides a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material. The device includes a sliding support base, a lithium battery, a heat-absorbing insulation layer, and a temperature sensing and monitoring device. The sliding support base includes a slide rail base and several detachable positioning plates. The detachable positioning plates are engaged with the slide rail base to fix the lithium battery and can be flexibly adjusted in spacing according to the different sizes of the lithium battery and the heat-absorbing insulation layer, making it suitable for lithium-ion battery packs with various battery shapes and different chemical systems. The heat-absorbing insulation layer, made of a flexible inorganic composite phase change material, surrounds the lithium battery and absorbs heat during normal battery operation to achieve thermal management, and provides a thermal barrier to block heat propagation when thermal runaway occurs. The temperature sensing and monitoring device monitors the battery temperature in real time, acquires battery operating status data, and triggers early warning and safety protection measures when the temperature data exceeds a set safety threshold.

[0009] The technical advantages of the lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material provided by this invention are as follows: The sliding support base consists of a slide rail base and several detachable positioning plates. These detachable positioning plates can be adjusted according to different sizes of lithium batteries and the heat-absorbing insulation layer, making the device suitable for lithium-ion battery packs of various shapes and chemical systems. By fixing the lithium battery, movement during use can be effectively prevented, reducing safety hazards caused by vibration or collision. The lithium battery itself is the core component of energy storage, and its performance directly affects the overall efficiency and safety of the device. By combining a high-performance lithium battery, the energy density and operating time of the device are improved. The heat-absorbing insulation layer is an important component of the device, made of a flexible inorganic composite phase change material. During normal operation, the heat-absorbing insulation layer effectively absorbs the heat released by the lithium battery, maintaining the battery's operating temperature within a safe range and preventing overheating. In the event of thermal runaway, the heat-absorbing insulation layer provides a thermal barrier, preventing heat spread and thus reducing the risk of fire or explosion. Temperature sensing and monitoring equipment is used to monitor the temperature of the lithium battery in real time. By monitoring the surface temperature of lithium batteries using thermocouples, accurate data on the battery's operating status can be obtained. When the temperature exceeds a set safety threshold, the device will trigger an alarm and take corresponding safety protection measures to prevent potential safety accidents in a timely manner.

[0010] Based on the above technical solution, the lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material of the present invention can be further improved as follows:

[0011] The heat-absorbing and insulating layer comprises an inorganic phase change material matrix, a silica microencapsulation layer, an ethylene-vinyl acetate copolymer flexible skeleton, and carbon nanotube thermally conductive reinforcing network fibers. The silica microencapsulation layer covers the outer surface of the inorganic phase change material matrix, the ethylene-vinyl acetate copolymer flexible skeleton impregnates and supports the silica microencapsulation layer, and the carbon nanotube thermally conductive reinforcing network fibers are dispersed in the ethylene-vinyl acetate copolymer flexible skeleton.

[0012] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the use of silica micro-encapsulation layer, ethylene-vinyl acetate copolymer flexible skeleton and carbon nanotube thermally conductive reinforced network fiber enhances the stability and thermal conductivity of the material.

[0013] Furthermore, the inorganic phase change material matrix is ​​composed of one or more of hydrated salts, molten salts, or metal-based phase change materials.

[0014] The beneficial effects of adopting the above-mentioned improved scheme are as follows: hydrated salts (such as Na2HPO4·12H2O) have high latent heat and suitable phase change temperature; molten salts and metal-based materials broaden the high-temperature application range; and composite design enhances the material's adaptability; the silica micro-encapsulation layer enhances the stability and encapsulation of the phase change material and prevents leakage; the flexible skeleton gives the material flexibility, allowing it to fit different battery surfaces; and the carbon nanotube network improves the thermal conductivity, accelerates heat absorption and diffusion, and further improves thermal management efficiency.

[0015] Furthermore, the heat-absorbing and insulating layer is a flexible sheet or molded structure that can fit the surface of lithium batteries of different shapes.

[0016] The beneficial effects of adopting the above-mentioned improvement scheme are: the sheet or molded structure is easy to install and replace, and the flexible and bendable structure reduces the adhesion between the phase change material and the battery surface, thereby improving the flexibility and ease of maintenance of the device.

[0017] Furthermore, the synthesis ratio of the inorganic phase change material matrix to the silica microencapsulation layer is 1:1 to 4:1, the addition range of the ethylene-vinyl acetate copolymer flexible skeleton is 20% wt to 60% wt, and the addition range of the carbon nanotube thermally conductive reinforced network fiber is 0.5% wt to 1.5% wt.

[0018] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by adjusting the addition ratio of inorganic phase change material matrix, silica microencapsulation layer, flexible skeleton and carbon nanotubes, the thermal management and safety performance of the material are further improved.

[0019] Furthermore, the temperature sensing and monitoring device includes a temperature-measuring thermocouple and a temperature anomaly and thermal runaway early warning device. The temperature-measuring thermocouple is attached to the surface of the lithium battery to monitor the surface temperature of the lithium battery. The temperature anomaly and thermal runaway early warning device is connected to the temperature-measuring thermocouple via a wire and connected in series with a comparator. The comparator has a safety threshold. When the temperature monitored by the temperature-measuring thermocouple exceeds the threshold, the wire between the temperature-measuring thermocouple and the temperature anomaly and thermal runaway early warning device is connected, triggering the temperature anomaly and thermal runaway early warning device to issue an alarm.

[0020] The beneficial effects of adopting the above-mentioned improvement scheme are: by linking the comparator and the alarm device, it is ensured that a timely response can be made in case of abnormal temperature, thereby enhancing the safety of the lithium battery.

[0021] A second aspect of the present invention provides a system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material, wherein the specific steps include:

[0022] The first step was to establish a coupled heat transfer model of battery-phase change material based on the COMSOL multiphysics simulation platform;

[0023] The second step involves simulating and optimizing key parameters such as the thickness of the phase change material, material characteristic parameters, and ambient temperature for battery packs with different chemical systems.

[0024] The third step is to determine the optimal system design scheme for the device.

[0025] The technical effects of the system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material provided by this invention are as follows: The device, through the application of a flexible inorganic composite phase change material, can effectively absorb battery heat during normal operation. Research data shows that it can reduce the peak temperature by more than 20% and control the temperature difference within 3°C, improving battery cycle life and safety. In the event of thermal runaway, the non-flammable properties of the inorganic phase change material prevent the material itself from being ignited, and the thermal insulation barrier reduces the peak temperature of thermal runaway, delaying and preventing the spread of thermal runaway. The system design optimization method quantifies the performance under different operating conditions through multi-physics simulation (such as thermo-mechanical-electrical coupling), optimizes parameter configuration, and improves design accuracy and efficiency. Combined with the device's sliding support base, the battery spacing can be flexibly adjusted according to the different sizes of the battery and the heat-absorbing insulation layer, making the device suitable for various battery shapes such as cylindrical and square, and battery packs with different chemical systems. The battery safety monitoring unit realizes intelligent monitoring and active protection, improving the system's automation level and response speed.

[0026] A coupled heat transfer model of a battery and phase change material (PCM) was established using the COMSOL multiphysics simulation platform. Utilizing COMSOL's multiphysics simulation capabilities, coupled analyses of multiple physical fields such as heat, force, and electricity can be performed on the same platform, thus more accurately simulating the heat transfer process between the battery and PCM. By establishing the coupled model, the temperature changes of the battery and the response of the PCM under different operating conditions can be predicted, helping designers identify potential thermal management problems at an early stage. The simulation results provide intuitive illustrations of key parameters (such as temperature distribution and heat flux density), laying the foundation for subsequent parameter optimization and design decisions.

[0027] For battery packs with different chemical systems, key parameters such as the thickness of the phase change material (PCM), material characteristic parameters, and ambient temperature are simulated and optimized. For different chemical systems (such as lithium iron phosphate and ternary lithium batteries), the thickness, thermal conductivity, and phase transition temperature of the PCM can be finely adjusted to meet the specific thermal management requirements of the battery. By optimizing the thickness and characteristic parameters of the PCM, the peak temperature of the battery can be effectively reduced. Simulations at different ambient temperatures ensure that the device maintains good thermal management performance under various actual operating conditions, improving the robustness of the equipment.

[0028] Determining the optimal system design scheme for the device involves a detailed analysis in the first two steps, which comprehensively considers various parameters of the phase change material to form an optimal system design scheme, effectively improving overall performance.

[0029] Based on the above technical solution, the system design optimization method of the lithium-ion battery thermal management and thermal runaway prevention device based on novel inorganic phase change materials of the present invention can be further improved as follows:

[0030] Furthermore, the specific steps for determining the optimal system design scheme of the device include:

[0031] Step 1: Conduct battery pack thermal management simulations at different battery rates and compare the monitored battery pack temperatures with safety thresholds.

[0032] Step 2: If the battery pack temperature is greater than the safety threshold, adjust the phase change material usage parameters and repeat step 1.

[0033] If the battery pack temperature is less than or equal to the safety threshold, then perform battery pack thermal management simulations under different ambient temperatures and compare the monitored battery pack temperature with the safety threshold.

[0034] Step 3: If the battery pack temperature is ≤ the safety threshold, adjust the coating mode of different phase change materials in the battery pack. If the temperature difference is < 5℃, output the comprehensive optimization scheme for the thermal management of the battery pack.

[0035] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: Simulating battery pack thermal management under different battery rates and comparing the monitored battery pack temperature with safety thresholds allows for real-time monitoring of the battery pack's temperature performance under different rate conditions, enabling timely detection of abnormal temperatures. By comparing with safety thresholds, it ensures that the battery pack will not overheat under high load operation, thus improving overall safety.

[0036] If the battery pack temperature exceeds the safety threshold, adjust the phase change material usage parameters and repeat step 1. If the battery pack temperature is less than or equal to the safety threshold, perform battery pack thermal management simulations under different ambient temperatures. Based on actual measured temperature data, automatically adjust the phase change material usage parameters (such as thickness and phase change temperature) to ensure the battery remains within its safe operating range. Simulations under different ambient temperatures further guarantee stable operation of the battery pack under various external conditions, preventing overheating caused by environmental changes.

[0037] If the battery pack temperature is ≤ the safety threshold, the coating mode of different phase change materials in the battery pack is adjusted. If the temperature difference is < 5℃, a comprehensive thermal management optimization scheme for the battery pack is output. By adjusting the coating mode of the materials, the space occupied by the phase change materials can be reduced without sacrificing thermal management performance, thereby improving the space utilization efficiency and energy density of the battery pack. The optimized design effectively avoids material waste while improving the economy and sustainability of the system.

[0038] Furthermore, the adjustment of phase change material usage parameters includes two methods: adjusting the thickness of the phase change material and adjusting the phase change temperature of the phase change material.

[0039] Furthermore, the sliding support base allows for flexible adjustment of the battery spacing based on the different sizes of the lithium battery and the heat-absorbing insulation layer, making the device suitable for battery packs with various battery shapes such as cylindrical and square, and different chemical systems.

[0040] Compared with existing technologies, the beneficial effects of the lithium-ion battery thermal management and thermal runaway prevention device and system design optimization method based on novel inorganic phase change materials provided by this invention are as follows: This invention innovatively adopts flexible inorganic composite phase change materials, which are both flexible and non-flammable, solving the flammability problem of traditional organic phase change materials; through multi-physics simulation optimization design, the device performance is quantified and customized, significantly improving thermal management efficiency (such as a 23.7% reduction in peak temperature) and thermal blocking capability (such as delayed propagation interval); the overall structure is simple, low-cost, and easy to scale up, providing a comprehensive solution for lithium-ion battery safety.

[0041] This device, by applying a novel inorganic phase change material, can effectively absorb the heat released by the battery under normal operating conditions, reducing the battery's peak temperature. Research data shows that it can reduce the peak temperature by more than 20% and control the internal temperature difference of the battery pack within 3°C. This excellent temperature control capability helps improve the battery's cycle life and overall performance. By optimizing the thickness and characteristic parameters of the phase change material, a more uniform temperature distribution can be achieved, thereby avoiding localized overheating and reducing battery performance degradation caused by uneven temperature distribution.

[0042] In the event of thermal runaway, the non-flammable properties of inorganic phase change materials effectively prevent the material itself from igniting. The thermal barrier within the device reduces the peak temperature of thermal runaway, delaying and preventing its propagation, thereby protecting the battery pack and its surrounding environment. The introduced battery safety monitoring unit enables intelligent monitoring, tracking battery temperature and status in real time, improving the system's automation level and response speed. Once an anomaly is detected, the system can quickly take measures (such as adjusting phase change material parameters or activating the cooling system) to minimize the risk of an accident.

[0043] Coupled heat transfer models based on the COMSOL multiphysics simulation platform enable designers to accurately predict the thermal behavior of batteries and phase change materials at an early stage. This process not only accelerates design iteration but also improves design accuracy. Simulation and optimization of different battery chemistry systems allow for flexible adjustment of key parameters such as the thickness of the phase change material and the phase change temperature according to specific needs, thereby ensuring optimal performance under different operating conditions.

[0044] By optimizing the thickness and coating pattern of the phase change material, the battery's thermal management performance is ensured while reducing material footprint and increasing the energy density of the battery pack. This design not only improves the economics of the equipment but also aligns with sustainable development requirements. The sliding support base design allows for flexible adjustment of the battery spacing, accommodating various battery shapes such as cylindrical and prismatic cells, as well as battery packs with different chemical systems. This flexibility enhances the product's market adaptability and meets the needs of diverse customers.

[0045] By simulating thermal management under different ambient temperatures, the robustness of the device under real-world operating conditions was enhanced. Regardless of high or low temperatures or varying humidity levels, the device maintains stable thermal management performance, effectively improving user experience and trustworthiness.

[0046] Through a series of simulations and optimizations, a comprehensive thermal management optimization solution for specific battery packs can be generated, ensuring that the battery maintains efficient and safe operation throughout its entire life cycle. This systematic solution not only provides clear guidance for customers but also lays the foundation for subsequent product maintenance and upgrades. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the overall structure of the lithium-ion battery thermal management and thermal runaway prevention device provided in an embodiment of the present invention;

[0048] Figure 2 An exploded view of the structure of the lithium-ion battery thermal management and thermal runaway prevention device provided in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the microstructure of the heat-absorbing and insulating layer (composite phase change material) in an embodiment of the present invention, as well as the microstructure and macroscopic flexibility characterization of the actual object.

[0050] Figure 4 This is a flowchart of the device system design optimization method based on the COMSOL multiphysics simulation platform provided in the embodiments of the present invention;

[0051] Figure 5 This is a comparison chart of thermal management performance test results in an embodiment of the present invention, showing a comparison of the temperature change trends of the battery pack before and after using the heat-absorbing insulation layer;

[0052] Figure 6 This is a comparison chart of thermal runaway prevention test results in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the simulation results for optimizing the thickness of the phase change material in an embodiment of the present invention;

[0054] The attached diagram lists the components represented by each number as follows:

[0055] 10. Sliding bracket base; 11. Slide rail base; 12. Detachable positioning plate; 20. Lithium battery; 30. Heat-absorbing insulation layer; 31. Inorganic phase change material matrix; 32. Silica micro-encapsulation layer; 33. Ethylene-vinyl acetate copolymer flexible skeleton; 34. Carbon nanotube thermally conductive reinforced network fiber; 40. Temperature sensing and monitoring equipment; 41. Temperature measuring thermocouple; 42. Temperature anomaly and thermal runaway early warning equipment. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0057] like Figure 1-2 The diagram shows a schematic of a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material, provided by the first aspect of this invention. The device includes a sliding support base 10, a lithium battery 20, a heat-absorbing insulation layer 30, and a temperature sensing and monitoring device 40. The sliding support base 10 includes a slide rail base 11 and several detachable positioning plates 12. The detachable positioning plates 12 are engaged with the slide rail base 11 to fix the lithium battery 20 and can be flexibly adjusted according to the different sizes of the lithium battery 20 and the heat-absorbing insulation layer 30, making it suitable for lithium-ion battery packs with various battery shapes and different chemical systems. The heat-absorbing insulation layer 30, made of a flexible inorganic composite phase change material, surrounds the lithium battery 20 and is used to absorb heat during normal battery operation for thermal management, and provides a thermal barrier to prevent heat spread when thermal runaway occurs. The temperature sensing and monitoring device 40 is used to monitor the battery temperature in real time, acquire battery operating status data, and trigger early warning and safety protection measures when the temperature data exceeds a set safety threshold.

[0058] like Figure 3As shown, in the above technical solution, the heat-absorbing and insulating layer 30 includes an inorganic phase change material matrix 31, a silica micro-encapsulation layer 32, an ethylene-vinyl acetate copolymer flexible skeleton 33, and carbon nanotube thermally conductive reinforcing network fibers 34. The silica micro-encapsulation layer 32 covers the outer surface of the inorganic phase change material matrix 31, the ethylene-vinyl acetate copolymer flexible skeleton 33 impregnates and supports the silica micro-encapsulation layer 32, and the carbon nanotube thermally conductive reinforcing network fibers 34 are dispersed in the ethylene-vinyl acetate copolymer flexible skeleton 33.

[0059] Furthermore, in the above technical solution, the inorganic phase change material matrix 31 is composed of one or more of hydrated salts, molten salts, or metal-based phase change materials.

[0060] Furthermore, in the above technical solution, the heat-absorbing and insulating layer 30 is a flexible sheet or molded structure that can fit the surface of lithium batteries of different shapes.

[0061] Furthermore, in the above technical solution, the synthesis ratio of inorganic phase change material matrix 31 to silica microencapsulation layer 32 is 1:1 to 4:1, the addition range of ethylene-vinyl acetate copolymer flexible skeleton 33 is 20% wt to 60% wt, and the addition range of carbon nanotube thermally conductive reinforced network fiber 34 is 0.5% wt to 1.5% wt.

[0062] Furthermore, in the above technical solution, the temperature sensing and monitoring device 40 includes a temperature measuring thermocouple 41 and a temperature anomaly and thermal runaway early warning device 42. The temperature measuring thermocouple 41 is attached to the surface of the lithium battery 20 to monitor the temperature of the lithium battery 20 surface. The temperature anomaly and thermal runaway early warning device 42 is connected to the temperature measuring thermocouple 41 through a wire and is connected in series with a comparator. The comparator is equipped with a safety threshold. When the temperature monitored by the temperature measuring thermocouple 41 exceeds the threshold, the wire between the temperature measuring thermocouple 41 and the temperature anomaly and thermal runaway early warning device 42 is connected, triggering the temperature anomaly and thermal runaway early warning device 42 to issue an alarm.

[0063] like Figure 4 The diagram shows an operation flowchart of a system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material, as provided in the second aspect of this invention. The specific steps in the diagram include:

[0064] The first step was to establish a coupled heat transfer model of battery-phase change material based on the COMSOL multiphysics simulation platform;

[0065] The second step involves simulating and optimizing key parameters such as the thickness of the phase change material, material characteristic parameters, and ambient temperature for battery packs with different chemical systems.

[0066] The third step is to determine the optimal system design scheme for the device.

[0067] Furthermore, in the above technical solution, the specific steps for determining the optimal system design scheme of the device include:

[0068] Step 1: Conduct battery pack thermal management simulations at different battery rates and compare the monitored battery pack temperatures with safety thresholds.

[0069] Step 2: If the battery pack temperature is greater than the safety threshold, adjust the phase change material usage parameters and repeat step 1.

[0070] If the battery pack temperature is less than or equal to the safety threshold, then perform battery pack thermal management simulations under different ambient temperatures and compare the monitored battery pack temperature with the safety threshold.

[0071] Step 3: If the battery pack temperature is ≤ the safety threshold, adjust the coating mode of different phase change materials in the battery pack. If the temperature difference is < 5℃, output the comprehensive optimization scheme for the thermal management of the battery pack.

[0072] Furthermore, in the above technical solution, adjusting the phase change material usage parameters includes two methods: adjusting the phase change material thickness and adjusting the phase change temperature.

[0073] Furthermore, in the above technical solution, the sliding support base 10 is used to flexibly adjust the battery spacing according to the different sizes of the lithium battery 20 and the heat-absorbing insulation layer 30, so that the device is suitable for battery packs with various battery shapes such as cylindrical and square and different chemical systems.

[0074] This invention provides a first embodiment: thermal management cycle simulation tests were conducted at different rates on a conventional battery pack and a battery module equipped with a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material. The results are shown in [the table below]. Figure 5 The peak temperatures of the conventional battery pack at 1C, 2C, and 3C discharge rates were 38.2°C, 52.9°C, and 62.5°C, respectively. The battery pack equipped with a novel inorganic phase change material thermal management device effectively reduced the peak temperatures at 1C, 2C, and 3C discharge rates to 37.1°C, 48.2°C, and 51.6°C, respectively, with temperature reductions of 1.1°C, 4.7°C, and 10.9°C, successfully lowering the dangerous temperature under conventional conditions to within the safe threshold.

[0075] Simulation tests of heated plate-thermal abuse-induced thermal runaway were conducted on conventional battery packs and battery packs equipped with a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material. The results are as follows: Figure 6 As shown. In a conventional battery pack ( Figure 6(a) In this module, all four battery cells experienced thermal runaway within 60-70 seconds after the heating plate was activated. The peak temperatures of the thermal runaway explosions all exceeded 900°C, reaching a maximum of 1212°C. The thermal runaway propagation speed was extremely fast, resulting in almost simultaneous failure. This indicates that under extreme conditions, unprotected conventional battery packs will face serious fire risks and thermal hazards. Figure 6 As shown in (b), the battery pack data after being equipped with the novel inorganic phase change material thermal management device shows that the first battery cell closest to the heating plate triggered thermal runaway at 66 seconds, with a peak temperature of 1148°C. Subsequently, the second cell also experienced a slight temperature rise at the same time as the first cell exploded, but the highest temperature only reached 225°C before quickly dropping back to room temperature, followed by a slow temperature rise. These phenomena indicate that the temperature rise of the second cell was due to the influence of the thermal runaway heat from the first cell, and it did not show any signs of thermal runaway itself. Similarly, the temperature curves of the third and fourth cells fluctuated more smoothly. The above simulation results confirm the effectiveness of the lithium-ion battery thermal management and thermal runaway prevention device based on the novel inorganic phase change material, successfully suppressing the propagation of thermal runaway within the battery pack, reducing the severity of the accident and minimizing the consequences.

[0076] The present invention provides a second embodiment: further, a system design optimization method based on multiphysics simulation is adopted ( Figure 4 A multi-parameter simulation optimization was performed on a battery pack equipped with a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material. The optimization analysis process and results are as follows: Figure 7 As shown, the effects of different phase change material thicknesses, different ambient temperatures, different phase change temperatures, and different coating modes on battery temperature are illustrated.

[0077] Figure 7(a) The effects of phase change material thickness (1, 2, 3, 4, 5, 6, 7, 8 mm) on battery temperature changes in battery packs equipped with a novel inorganic phase change material thermal management device at different discharge rates of 1C, 2C, and 3C are presented. At a 1C discharge rate, the overall battery temperature is low, and the battery temperature curves corresponding to different phase change material thicknesses are very close, with a temperature difference of less than 2°C. At a 2C discharge rate, the difference between different curves increases, with the peak difference between the temperature curves of batteries with material thicknesses of 1 mm and 8 mm increasing to 5°C. These data indicate that changing the material thickness has no significant effect on battery temperature at low discharge rates. At 3C discharge rate, the battery temperature rise rate accelerates significantly. Therefore, the difference in temperature control effect between phase change materials (PCMs) of different thicknesses becomes apparent. Specifically, at thicknesses of 1 mm and 2 mm, the latent heat of the material is quickly exhausted, resulting in a surge in battery temperature at the end of discharge, reaching 61°C and 58°C respectively. As the PCM thickness increases to 3-8 mm, the temperature rise is alleviated and suppressed to varying degrees, with the final temperature decreasing to 50-53°C and below, and no further surges observed. However, similar temperature curves still appear at this stage. Therefore, these results indicate that the thickness of the PCM is a key factor affecting its thermal management performance. However, for large-volume batteries or high-rate operation, simply increasing the PCM thickness has limited improvement on temperature rise control; adjustments to other parameters are necessary.

[0078] In situations where adjusting the thickness of the phase change material has limited effect on temperature optimization, Figure 7(b) The effect of the phase change temperature (Tpcm) of the phase change material on thermal management performance was further investigated. The figure shows the battery temperature variation curves of the battery pack equipped with the novel inorganic phase change material thermal management device at 1C, 2C, and 3C discharge rates, with phase change temperatures of 30°C, 35°C, 40°C, 45°C, 50°C, and 55°C. At the 1C discharge rate, the discharge temperature curves almost overlap when Tpcm is 50°C, 45°C, and 40°C. This is because the overall battery temperature is low under this condition and has not reached the phase change range (battery temperature < 40°C). Therefore, the phase change material used needs a lower phase change temperature to show a significant phase change plateau (e.g., a significant temperature drop at Tpcm = 35°C and 30°C). At a 2C discharge rate, when Tpcm is 55°C and 50°C, the battery temperature curves are similar, indicating that the battery temperature is not entirely affected by the phase transition range of the phase change material. When Tpcm continues to decrease to 45°C, 40°C, 35°C, and 30°C, the battery temperature rise curves exhibit a clear regularity: the lower the Tpcm, the earlier the corresponding temperature curve flattens out, and the lower the battery temperature at the end of discharge. Compared to the former, the phase change material shows better temperature control after reducing Tpcm. The results show that lowering the phase transition temperature allows the material to initiate the phase transition endothermic process in the early stages of discharge when the battery temperature is relatively low, thus suppressing battery temperature rise earlier and more effectively. Similarly, at 3C discharge rates, the influence of different Tpcm on temperature follows the same trend as at 2C, but the temperature differences between the curves are more significant, and the overall temperature rise rate is faster. At this high discharge rate, phase change materials with Tpcm of 40°C and 45°C exhibit better cooling performance, with their temperature trends significantly lower than those with higher Tpcm (50°C, 55°C). This avoids the problem of premature termination of the phase change process and the undesirable temperature surge at the end of discharge that can occur with excessively low Tpcm: for example, the highest temperature at Tpcm=35°C is higher than the highest temperature at Tpcm=40°C / 45°C. In summary, phase change temperature is a key parameter for optimizing thermal management performance. Appropriately reducing the phase change temperature within a certain range, and flexibly adjusting the thickness of the phase change material, allows the phase change material to fully utilize its latent heat advantage in the early stages of discharge, significantly delaying battery temperature rise and reducing the maximum temperature, thereby effectively improving the efficiency and adaptability of the thermal management system.

[0079] To comprehensively evaluate the environmental adaptability of thermal management devices based on novel inorganic phase change materials, Figure 7(c) The influence of different ambient temperatures (Ta) on its thermal management performance was investigated. The figure shows the battery temperature change curves at 1C, 2C, and 3C discharge rates with ambient temperatures of 15°C, 25°C, 35°C, and 45°C, respectively. Each curve corresponds to an ambient temperature gradient; specifically, the higher the Ta, the higher the overall battery temperature. For example, at a 1C discharge rate, the battery temperature rise is gradual, and all four temperature curves are within a safe range. At a 2C discharge rate, the curves at different ambient temperatures exhibit a clearer stepped distribution. The curve with Ta=15°C at the end of discharge has the lowest temperature, approximately 40°C, while the curve with Ta=45°C has the highest temperature, approximately 65°C, entering the danger zone. Similarly, at a 3C discharge rate, the battery temperature rise rate is significantly faster, and the trend is steeper; the discharge temperature is more dangerous at high temperatures of Ta=35°C and 45°C. It can be seen that the temperature curves have similar trends under different ambient temperatures, but the final temperature peaks differ due to different discharge rates. When the battery temperature exceeds the safety threshold at a specific ambient temperature and discharge rate, it is necessary to consider adjusting the thickness of the phase change material and the phase change temperature parameters to control the temperature within a safe range.

[0080] Specifically, the principle of this invention is as follows: During use, inorganic phase change material is uniformly coated or filled around the battery pack according to the design scheme, ensuring good contact between the phase change material and the battery surface to achieve effective heat conduction. Temperature sensors and monitoring units are connected to the battery pack to ensure real-time monitoring of battery temperature, charge / discharge status, and other safety parameters. The battery management system is activated, and all sensors and monitoring devices are ensured to be functioning properly. Data acquisition is checked for real-time effectiveness, ensuring the equipment is in standby mode. During normal charge / discharge, the monitoring system collects real-time temperature data of the battery and phase change material, comparing it with set safety thresholds. The phase change material and monitoring system are regularly inspected and maintained to ensure stable performance, especially after prolonged use, where the condition of the phase change material needs to be checked to confirm no leakage or performance degradation. The data collected by the monitoring system is analyzed to observe the battery's performance under different operating conditions. The position, thickness, and other parameters of the phase change material are adjusted as needed to optimize thermal management. If the monitoring system detects abnormal temperature or other safety hazards, the emergency plan should be activated immediately. Data from each operation is recorded, including temperature changes, charge / discharge status, and fault alarms, for subsequent analysis and improvement. After use, shut down the machine safely according to the operating procedures, turn off the power, and disconnect all connections.

[0081] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material, characterized in that, The device includes a sliding support base (10), a lithium battery (20), a heat-absorbing insulation layer (30), and a temperature sensing and monitoring device (40). The sliding support base (10) includes a slide rail base (11) and several detachable positioning plates (12). The detachable positioning plates (12) are engaged with the slide rail base (11) to fix the lithium battery (20) and can be flexibly adjusted according to the different sizes of the lithium battery (20) and the heat-absorbing insulation layer (30), making it suitable for lithium-ion battery packs with various battery shapes and different chemical systems. The heat-absorbing insulation layer (30) is wrapped around the lithium battery (20) and is made of flexible inorganic composite phase change material. It is used to absorb heat during normal battery operation to achieve thermal management and to provide a thermal barrier to block heat spread when thermal runaway occurs. The temperature sensing and monitoring device (40) is used to monitor the battery temperature in real time, obtain battery operating status data, and trigger early warning and safety protection measures when the temperature data exceeds a set safety threshold.

2. The lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 1, characterized in that, The heat-absorbing and insulating layer (30) includes an inorganic phase change material matrix (31), a silica micro-encapsulation layer (32), an ethylene-vinyl acetate copolymer flexible skeleton (33), and carbon nanotube thermally conductive reinforcing network fibers (34). The silica micro-encapsulation layer (32) covers the outer surface of the inorganic phase change material matrix (31), the ethylene-vinyl acetate copolymer flexible skeleton (33) impregnates and supports the silica micro-encapsulation layer (32), and the carbon nanotube thermally conductive reinforcing network fibers (34) are dispersed in the ethylene-vinyl acetate copolymer flexible skeleton (33).

3. The lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 2, characterized in that, The inorganic phase change material matrix (31) is composed of one or more of hydrated salts, molten salts, or metal-based phase change materials.

4. The lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 3, characterized in that, The heat-absorbing and insulating layer (30) is a flexible sheet or molded structure that can fit the surface of lithium batteries of different shapes.

5. A lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 4, characterized in that, The synthesis ratio of the inorganic phase change material matrix (31) to the silica microencapsulation layer (32) is 1:1 to 4:1, the addition range of the ethylene-vinyl acetate copolymer flexible skeleton (33) is 20% wt to 60% wt, and the addition range of the carbon nanotube thermally conductive reinforced network fiber (34) is 0.5% wt to 1.5% wt.

6. The lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 5, characterized in that, The temperature sensing and monitoring device (40) includes a temperature measuring thermocouple (41) and a temperature anomaly and thermal runaway early warning device (42). The temperature measuring thermocouple (41) is attached to the surface of the lithium battery (20) and is used to monitor the temperature of the surface of the lithium battery (20). The temperature anomaly and thermal runaway early warning device (42) is connected to the temperature measuring thermocouple (41) by a wire and is connected in series with a comparator. The comparator is equipped with a safety threshold. When the temperature monitored by the temperature measuring thermocouple (41) exceeds the threshold, the wire between the temperature measuring thermocouple (41) and the temperature anomaly and thermal runaway early warning device (42) is connected, triggering the temperature anomaly and thermal runaway early warning device (42) to issue an alarm.

7. The system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 6, characterized in that, The specific steps include: The first step was to establish a coupled heat transfer model of battery-phase change material based on the COMSOL multiphysics simulation platform; The second step involves simulating and optimizing key parameters such as the thickness of the phase change material, material characteristic parameters, and ambient temperature for battery packs with different chemical systems. The third step is to determine the optimal system design scheme for the device.

8. The system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 7, characterized in that, The specific steps for determining the optimal system design scheme of the device include: Step 1: Conduct battery pack thermal management simulations at different battery rates and compare the monitored battery pack temperatures with safety thresholds. Step 2: If the battery pack temperature is greater than the safety threshold, adjust the phase change material usage parameters and repeat step 1. If the battery pack temperature is less than or equal to the safety threshold, then perform battery pack thermal management simulations under different ambient temperatures and compare the monitored battery pack temperature with the safety threshold. Step 3: If the battery pack temperature is ≤ the safety threshold, adjust the coating mode of different phase change materials in the battery pack. If the temperature difference is < 5℃, output the comprehensive optimization scheme for the thermal management of the battery pack.

9. The system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 8, characterized in that, The adjustment of phase change material usage parameters includes two methods: adjusting the thickness of the phase change material and adjusting the phase change temperature of the phase change material.

10. The system design optimization method for a lithium-ion battery thermal management and thermal runaway prevention device based on a novel inorganic phase change material according to claim 9, characterized in that, The sliding bracket base (10) is used to flexibly adjust the battery spacing according to the different sizes of the lithium battery (20) and the heat-absorbing insulation layer (30), so that the device is suitable for battery packs with various battery shapes such as cylindrical and square and different chemical systems.

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