Hollow Carbon Fiber Architectures Fabricated via Carbide‐Derived Carbon Strategy for Ultra‐Lightweight Thermal Protection Systems

Abstract Carbon‐based insulation materials exhibit remarkable potential for use in thermal protection systems (TPS) in extreme environments such as hypersonic vehicles and deep‐space missions. This is attributed to their ultralight structure, exceptional thermal insulation properties, and outstanding high‐temperature stability. Nevertheless, traditional carbon aerogels frequently experience significant volume shrinkage during fabrication, which makes it challenging to optimize their structural and thermal performance. Inspired by the performance enhancement induced by hollow fiber structures, a carbide‐derived carbon (CDC) strategy was employed in this study to fabricate a hollow carbon fiber‐based porous insulation material (CF‐H); carbon fiber felt (CF) was used as the structural template. The CDC strategy combined the template method with a conformal transformation mechanism to achieve minimal volume shrinkage (10.22%) and high porosity (98.84%). The hollow fiber framework reduced density (19 mg·cm ⁻³ ), minimized heat transfer, and provided low thermal conductivity (0.09553 W·m ⁻¹ ·K ⁻¹ at 300 °C). Moreover, CF‐H retained the needle‐punched architecture of the CF template, thereby exhibiting excellent elasticity under mechanical stress. In conclusion, applying the CDC strategy to develop lightweight, high‐performance carbon‐based insulation materials offers a novel perspective on design and development of TPS insulation for application in extreme aerospace conditions.