Constructing Water-Retaining/Ion-Regulating Bi-Layers for Highly Durable, All-Climate, Efficient Moisture Electric...

Moisture electric generators (MEGs), which can directly convert chemical energy in moisture into electricity have demonstrated great potential for powering wearable electronics and IoT devices. However, state-of-the-art MEGs suffer from transient power output and rely on high relative humidity (RH) as well as mild temperature, hampering their practical applications. Herein, a novel high-performance MEG is reported by designing ionic hydrogel and graphene oxide dual-layered devices, where the water-enriched hydrogel enables continuous power outputs under various conditions while the inherent layering nanochannels effectively regulate ion diffusion for stable and efficient performance improvement. The MEG can generate a maximum power density of 71.7 µW cm^-2 and continuously output 0.6 V for more than 1400 h at room condition without degradation. Most importantly, the developed generator can operate well from -20 °C to 50 °C, and an ultrahigh and stable voltage of 1.2 V is realized at RH of 0% owing to the dynamic water equilibrium in the system. The MEG also displays excellent self-restoration capabilities, demonstrating high cyclic-performing potential. This work may provide important guidelines in designing long-life all climate applicable energy harvesting devices through designing synergistic bilayers architecture.