Large-Scale Production of Flexible, High-Voltage Hydroelectric Film Based on Solid Oxides.

Spontaneous electricity generation through water evaporation is becoming a hot research area. However, low power output, limited material availability and unscalable fabrication largely hinder its wide applications. Here, we report scalable painting and blade coating approaches for mass production of flexible hydroelectric film (HEF) based on solid oxides (e.g., Al2O3), which is of tolerance to mechanical deformation and is compatible with three-dimensional diverse configuration. The electricity power is generated continuously and can last for more than 10 days in the ambient condition. A single HEF unit is capable of supplying an output voltage of more than 2.5 V, and even up to 4.5 V at specific condition. The accumulative energy output can be tuned conveniently by means of series/parallel connection or size control to meet the practical needs of commercial electronics. A family of solid oxides has been verified to have the ability for water evaporation induced electricity generation, which offers a considerable room for development of high performance energy-supplying devices.