All‐In‐One Thermal Protection: Multifunctional Synergy in Hierarchically Structured Dual‐Oxide Nanofiber Aerogel

Abstract Ceramic nanofiber aerogels are emerging as promising thermal protection materials, yet their brittleness remains a critical challenge. This work designs a hierarchical fibrous aerogel consisting of streamlined dual‐oxide nanofibers featuring a dense‐sheath/porous‐core architecture, simultaneously overcoming the intrinsic fragility while enabling thermal‐protection. The obtained aerogel demonstrates ultra‐low thermal conductivity and exceptional thermomechanical stability a high working temperatures. The aerogel structure, constructed from arbitrarily bendable nanofibers, reduces the overall density and effectively lowers thermal conductivity. The minimum density can reach as low as 8 mg·cm ⁻³ . This unique structure enhances the mechanical stability of the entire aerogel in a wide working temperature (−196 to 1300 °C) upon 80% compression. The thermal conductivity achieves an extremely low value of 7 mW·m ⁻¹ ·K ⁻¹ . These attributes originate from the following mechanisms: depressing heat transfer by prolonging heat conduction pathways and offering interfacial insulation, while impeding phonon transport within nanopores. Upon simulated space‐ground integrated experiments at ≈1200 °C, the ceramic nanofiber aerogel exhibits remarkable resistance to thermal vibration. The nanofiber aerogel can serve as an all‐in‐one platform to synergistically integrate noise absorption and catalytic conversion, thereby paving the way for future practical applications.