A flexible double network aerogel reinforced by SiO₂/ZrO₂ fibers paper with excellent thermal insulation at high-temperature

Silica aerogel composites reinforced by fibers (SRF) have been used as thermal insulation walls to suppress lithium-ion batteries (LIBs) thermal runaway in electric vehicles. Increasing energy density of lithium-ion batteries brings out the requirement of higher temperature resistance and better thermal insulation performance of silica aerogel composites. Herein, we report a simple strategy for preparing aerogel reinforced by ZrO₂/SiO₂ fibers papers (AZSP) with double network structure for thermal insulation at high-temperature by conventional papermaking process and sol-gel method. The papermaking process made long fibers oriented perpendicular to thickness and opacifier ZrO2 fibers dispersed evenly in composites and mesoporous silica aerogels were filled in nanofibers skeleton. AZSP exhibited an excellent thermal insulation property at high-temperature with thermal conductivity of 0.039 W/(m·K) at 500 °C. The nanofibers reinforcement had been found to impart several desirable attributes to the material, including high flexibility, smooth surface suitable for stamping, painting, writing, or printing, and tensile stress of 0.74 MPa, thus rendering it an attractive option for diverse applications. Furthermore, the exceptional thermal stability of AZSP was demonstrated by the absence of any significant shrinkage deformation upon exposure to a butane flame. These remarkable properties, in conjunction with its high flexibility and thermal insulation performance, made AZSP a promising candidate for utilization as an insulation material for electric vehicle thermal management systems to mitigate the risk of thermal runaway.