Lightweight and Resilient ZrO2–TiO2 Fiber Sponges with Layered Structure for Thermal Insulation

Low density, heat‐resistant sponge‐like fiber assembly materials are considered as promising high‐temperature insulation materials. However, the poor structural stability, infrared radiation heat transfer, and complex preparation process limit its further application. Herein, a facile method to create ultralow‐density ZrO 2 –TiO 2 fiber sponges by the electrospinning method followed by heat treatment is presented. The layered structure sponges treated at 1200 °C have a low density of 9.5 mg cm −3 . Moreover, the sponges possess high compressibility and good compression resistance over a wide temperature range from −196 to 1200 °C. In addition, the sponges exhibit low thermal conductivity of 27 mW m −1 K −1 , robust fire resistance, and high near‐infrared reflectance, making them an ideal alternative for high‐temperature thermal insulation materials.