Solar-Complemented Moisture Electric Generator for Synergistic Energy Harvesting in All Regions

Abstract

Moisture-enabled generators (MEGs) can harvest electrical energy from ambient water vapor, offering a promising self-powered solution for wearable electronics and Internet-of-Things systems. However, their practical application is hindered by limited output power (<50 μW cm-2) and the lack of effective strategies for synergistic energy harvesting in all regions on Earth. Herein, we report a hybrid generator capable of simultaneously harvesting moisture and solar energy. The device integrates a highly hygroscopic dual-crosslinked ionic conductive hydrogel as the moisture-induced electrical layer with a TiO2-based photovoltaic layer for solar energy conversion. A laser-patterned carbon electrode serves as a shared electrode, enabling dual energy conversion and utilizing solar-induced heat to further enhance moisture-driven power generation. Under standard solar illumination and 60% relative humidity, the hybrid generator delivers a stable direct-current output of 0.75 V, a current density of 1.2 mA cm-2, and a peak power density of ~ 0.37 mW cm-2. Importantly, stable and reliable operation across diverse climatic regions such as Shanghai, Kinshasa, London, and Gothenburg is verified through global-scale climate analysis and urban-environment simulations, demonstrating the robustness and all-region applicability of the proposed system. Furthermore, the device enables fully self-powered wireless positioning and alarm functions, highlighting its potential for deployment in complex and emergency scenarios.