Elastic lamellar-structured ZrB2-SiC ceramic nanofiber aerogels for efficient thermal insulation

Ceramic aerogels, recognized as lightweight, low thermal conductivity, and chemically stable thermal insulation materials. However, their inherent brittleness leads to low mechanical strength and poor compressive performance, and there is still the problem of relatively high thermal conductivity at high temperatures. Herein, we developed a lamellar zirconium boride-silicon carbide (ZrB 2 -SiC) ceramic nanofiber aerogel via electrospinning, achieving an ultralow density (53 mg·cm −3 ), high elasticity (40% recoverable strain), and ultralow thermal conductivity (0.038 W·m −1 ·K −1 at room temperature). The excellent elasticity originates from the interaction between hard nanoparticles (ZrB 2 , SiC) and soft amorphous phases (SiO x C y , carbon) within the fibers, synergistically reinforced by the lamellar structure. Meanwhile, the extremely low thermal conductivity is attributed to the multiscale porous network, the abundant heterogeneous interfaces, and the enhanced radiation heat dissipation. These mechanisms, supported by both experimental characterization and theoretical simulations, provide new insights for lightweight structures with intrinsic elasticity and high-efficiency thermal insulation capabilities.