In order to improve the high-temperature resistance and thermal insulation of SiC nanofiber aerogel, the structural design and preparation of SiC nanofiber composite aerogel felt were carried out based on the heat transfer mechanism. A novel multi-layer SiC nanofiber aerogel felt was prepared with the ablative layer (ZrO 2 /ZrSiO 4 anti-oxidation layer), opacifiers layer (TiO 2 and SiC), and heat insulation layer (SiC nanowire aerogel). Compared with the single SiC nanowire aerogel, the oxidation resistance temperature of SiC nanofiber composite aerogel felt increased from 1300 ℃ to 1500 ℃ during aerobic calcination. With the butane gun ablation, the back temperature of the single SiC nanofiber aerogel felt was 308 ℃, while the back temperature of the composite aerogel felt was only 130 ℃. The structural design of the multi-layer SiC nanofiber composite aerogel felt provides an approach to improving thermal insulation properties in extreme environments.
Phase change materials (PCMs) are susceptible to fire and may accelerate heat transfer when thermal runaway propagation (TRP) in lithium-ion battery (LIB) modules, requiring the design and safe use of insulation structures with excellent flame-retardant properties. In this work, the sandwich structure composed of flame-retardant phase change material (FRPCM) combined with aerogel felt (AEGF) is used to study the inhibitory effect on TRP of pouch battery modules (BMs). The structural materials are applied between cells, and the changes of temperature, voltage, mass and other parameters in the TRP process are analyzed by changing the thickness of FRPCMs and AEGFs, and the changes of heat flux of materials were also qualitatively analyzed. The results show that the increase of FRPCM and AEGF thickness can increase the interval time of TRP and reduce the overall thermal risk of the BMs. Compared to Test-1, the increase in TRP time between cells 1 and 2 in Test-2 to Test-5 ranged from 52.7% to 358.7%, and the longest thermal runaway interval reached 844 s. Both the structural materials in Test-6 and Test-7 block the TRP. Combining the thermal conductivity of PCMs and the thermal insulation properties of AEGFs, this work can effectively conduct heat to the environment and block the TRP when applied to BMs, which provides a valuable reference for efficient inhibition and blocking of TRP.