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.