Multimode Thermal Gating Based on Elastic Ceramic-Carbon Nanowhisker/Nanofiber Aerogels by Strain Engineering Strategy
Xinyi Chang, Xiaota Cheng, Xia Yin, Renchao Che, Jianyong Yu, Yi‐Tao Liu, Bin Ding
Abstract
The capability to regulate heat transport dynamically and reversibly within solid materials propels advancement in aerospace conditioning, battery thermal control, and energy harvesting/conversion industries. Although aerogels are known for thermal insulation properties, their constant thermal resistance induced by immutable pore structure makes them struggle to reverse-release the accumulated thermal energy. Here, we develop a nanocrystalline whisker/nanofiber aerogel (WFA) thermal gating induced by the self-catalyzed growth strategy, whose elasticity offers possibilities for dynamic thermal management. Thermal conductivities can be continuously regulated by external compressive strain-trigged heat conduction pathway and interfacial resistance variations, switching seamlessly between 0.020 W m –1 K –1 in an uncompressed state and 0.071 W m –1 K –1 at 80% compressive strain, with a modulation ratio of ∼3.55. The integral inorganic nature ensures the thermal stability of WFAs over a large thermal gradient, from −196 °C deep cryogenic to 1500 °C ultrahigh temperature. The resulting multimode WFAs provide a feasible solution for thermal management in extreme environments.