Superelastic ceramic aerogels up to 2200 °C

Ceramic aerogels hold great promise for thermal insulation, yet their elasticity and operating temperature fall short for extreme applications. Here, we design an entropy-stabilized amorphous-crystalline hybrid structure and develop (Hf, Zr, Ta, Nb, Ti)C high-entropy carbide nanofibrous aerogels. These aerogels exhibit a recoverable strain up to 99%, a low thermal conductivity of 21–66 mW·m−1·K−1 across 25–1000 °C, and a high operating temperature up to 2200 °C under argon. The integration of these appealing characteristics makes the aerogels highly promising for extreme applications, ranging from deep-space exploration to next-generation energy vehicles. This study not only presents a highly competitive candidate for advanced thermal insulation but also furnishes a design paradigm for enhancing the mechanical and thermal performance of ceramic insulators. To improve the elasticity and service temperature of ceramic aerogels, this work designs and fabricates high-entropy carbide nanofibrous aerogels with an amorphous-crystalline structure, achieving 99% recoverable strain and 2200 °C operation in argon.