Superelastic Barium–Magnesium Aluminate Nanofibrous Aerogels for Synergistic Thermal Insulation and Fire Shielding

Traditional ceramic particle aerogels often suffer from insufficient mechanical strength and are prone to catastrophic fracture under stress, which severely limits their stability and safety in practical applications. In this study, the lightweight and elastic barium–magnesium aluminate nanofibrous aerogels (BMAO NFAs) were prepared using electrospinning combined with high-temperature calcination. The BMAO NFAs achieve mechanical reinforcement and functional enhancement by assembling flexible one-dimensional nanofibers into robust three-dimensional materials. They exhibit synergistic thermal insulation and flame shielding properties with a maximum service temperature of 1400 °C, a low room-temperature thermal conductivity of 0.030 W·m–1·K–1, a low density of 12 mg·cm–3, and a great compressive strength of approximately 12 kPa at 80% strain, endowing BMAO NFAs with broad potential for thermal management under extreme conditions. This study provides a way to develop ceramic aerogels with effective thermal insulation and fire shielding.