Highly compressible and stretchable ceramic aerogels with nanofiber-nanosheet binary synergistic structure for thermal insulation in extreme environments

Ceramic aerogels are ideal candidates for thermal insulation in extreme environments because of their high porosity, low thermal conductivity, and chemical and thermal inertness. However, the intrinsic rigidity and brittleness of ceramic aerogels hinder their practical application. In this study, we designed a composite mullite aerogel with a nanofiber-nanosheet binary synergistic structure to obtain superior thermal insulation properties and robust mechanical performance. Composite aerogels were manufactured by combining electrospinning and freeze-drying. They exhibited superior temperature-invariant compressibility, flexibility, stretchability, fatigue tolerance, and thermal insulation performance. Our study will enable the innovative design of mechanically reliable ceramics for numerous extreme applications ranging from battery protection to space exploration.