Ceramic aerogels constructed from dense, non-porous ceramic nanofibers with robust and elastic properties up to 1300 °C

Elastic and compressible 3D nanomaterials comprising polymers, carbon, and metals have been prepared quantitatively in different formats. However, creating flexible and elastic ceramic aerogels with high thermal stability remains a significant challenge. In this study, sols composed of highly condensed inorganic molecular chains can be used to prepare ceramic nanofiber aerogels without adding polymers. This strategy prevents many pore defects caused by the thermal decomposition of polymers during ceramization and avoids the stress concentration generated by pore defects, which could lead to irreversible structural damage to the ceramic nanofiber aerogels under external forces. The synthesized ceramic nanofiber aerogel possesses temperature-invariant superelasticity (up to 1300 °C) and fatigue resistance to thousands of compressions with a thermal conductivity of only 0.028 W m −1  k −1 . The successful synthesis of such aerogels is expected to provide a foundation for designing flexible and elastic ceramic aerogels with structural adaptability and scalability.