Ultrastrong and Reusable Solar‒Thermal‒Electric Generators by Economical Starch Vitrimers

Abstract In frigid regions, it is imperative to possess functionality materials that are ultrastrong, reusable, and economical, providing self‐generated heat and electricity. One promising solution is a solar‒thermal‒electric (STE) generator, composed of solar‒thermal conversion phase change composites (PCCs) and temperature‐difference power‐generation‐sheets. However, the existing PCCs face challenges with conflicting requirements for solar‒thermal conversion efficiency and mechanical robustness, mainly due to monotonous functionalized aerogel framework. Herein, a novel starch vitrimer aerogel is proposed that incorporates orientational distributed carboxylated carbon nanotubes (CCNT) to create PCC. This innovative design integrates large through‐holes, mechanical robustness, and superior solar‒thermal conversion. Remarkably, PCC with only 0.8 wt.% CCNT loading achieves 85.8 MPa compressive strength, 102.4 °C at 200 mW cm⁻² irradiation with an impressive 92.9% solar–thermal conversion efficiency. Noteworthy, the STE generator assembled with PCC harvests 99.1 W m⁻² output power density, surpassing other reported STE generators. Strikingly, even under harsh conditions of −10 °C and 10 mW cm^‒2 irradiation, the STE generator maintains 20 °C for PCC with 325 mV output voltage and 45 mA current, showcasing enhanced electricity generation in colder environments. This study introduces a groundbreaking STE generator, paving the way for self‐sufficient heat and electricity supply in cold regions.