Synergistic Infrared Shading Effects Endowing Core–Shell SiC@C Fibrous Aerogel with Ultrahigh Temperature Resistance and Ultralow Thermal Conductivity

Abstract Advanced thermal insulation materials that exhibit exceptional high‐temperature stability, ultralight characteristics, and recoverable compressibility under extreme conditions are in increasing demand. Emerging ceramic fibrous aerogels are promising next‐generation materials. However, traditional ceramic aerogels exhibit high thermal conductivity and inadequate thermal stability, resulting in catastrophic structural failure at temperatures above 1500 °C. Herein, a novel core–shell SiC@C fibrous aerogel with a 3D interlocked lamellar structure is fabricated by optimizing centrifugal spinning parameters, followed by high‐temperature sintering. This ultralight aerogel with a density of 20.5 mg cm −3 exhibits good flexibility and processability. In addition, the aerogel demonstrates remarkable stability after being treated at 2100 °C for 1 h in argon, or at 1600 °C for 1 h in air, showing unchanged 3D architectures and good compression resilience. The synergistic infrared shading effects of the carbon shell and SiC core endowed this aerogel with record‐breaking thermal‐insulation performance, achieving an ultralow thermal conductivity of 82.3 mW (m K) −1 at 1000 °C, lower than most ceramic fibrous aerogels reported to date. These exceptional thermomechanical and thermal‐insulation properties make fibrous aerogels prime candidates for providing robust thermal protection under extreme conditions.