Self‐Charged Dual‐Photoelectrode Vanadium–Iron Energy Storage Battery

The efficient utilization of solar energy in battery systems has emerged as a crucial strategy for promoting green and sustainable development. In this study, an innovative dual‐photoelectrode vanadium–iron energy storage battery (Titanium dioxide (TiO2) or Bismuth vanadate (BiVO4) as photoanodes, polythiophene (pTTh) as photocathode, and VO2+/Fe3+ as redox couples.) is proposed, which can autonomously charge under sunlight. The dual‐photoelectrode structure enables the efficient harnessing of solar energy. All processes are spontaneous and do not require external power sources. It is noteworthy that the vanadium–iron energy storage battery demonstrates excellent stability and remarkably low cost. The results show that the combinations of TiO2‐pTTh and BiVO4‐pTTh as photoelectrodes achieve spontaneous conversion rates of 29.17% and 25.46% for VO2+ and 25.6% and 23% for Fe3+ after 4 h of light charging. This study offers a promising solution for the development of large‐scale, low‐cost solar energy storage batteries. A novel double‐photoelectrode vanadium–iron energy storage battery with a self‐charging function under sunlight is proposed. The battery is comprised of a bandgap‐matched semiconductor photoelectrode and a ferrovanadium electrolyte. The structure of two photoelectrodes makes it possible to convert solar energy directly into electrical energy. This innovative solution holds great potential for advancing the development of large‐scale and cost‐effective solar batteries.