Lightweight and Mechanically Robust Ambient-Electrospun Nanofibrous Sponges Combined with Solar-Driven Active Heating and Low-Temperature Superinsulation.

Traditional fibrous warmth retention materials suffer from limited performance improvement due to their micrometer-scale diameter and fail to meet the requirements of lightweight yet high-efficiency cold protection in extreme environments. Herein, we present a novel, facile, and ecofriendly strategy to fabricate a lightweight, mechanically robust nanofibrous sponge with integrated solar-driven active heating and low-temperature superinsulation. The high-porosity structure is achieved through urea-induced phase separation during ambient electrospinning, which overcomes the energy-intensive and unsafe high-humidity processing challenges. Simultaneous in situ incorporation of silicon carbide nanoparticles with photothermal properties enables solar-activated heat generation. This nanofibrous sponge realizes dual functionalities: ultralow thermal conductivity (27.31 mW m K) for low-temperature superinsulation and rapid solar heating (50.1 °C temperature rise within 10 min under simulated sunlight), combined with exceptional attributes including lightweight property (volume density of 3.8 mg cm), hydrophobicity (water contact angle = 128°), antifouling behavior, and stable mechanical performance. Its superior performance in extreme environments (e.g., high-altitude and polar regions) and medical applications establishes a new paradigm for advanced warmth retention materials with integrated passive/active thermal management functionalities.