Carbon superstructure‐supported half‐metallic V2O3 nanospheres for high‐efficiency photorechargeable zinc ion batteries

Photorechargeable zinc ion batteries (PZIBs), which can directly harvest and store solar energy, are promising technologies for the development of a renewable energy society. However, the incompatibility requirement between narrow band gap and wide coverage has raised severe challenges for high‐efficiency dual‐functional photocathodes. Herein, half‐metallic vanadium (III) oxide (V2O3) was first reported as a dual‐functional photocathode for PZIBs. Theoretical and experimental results revealed its unique photoelectrical and zinc ion storage properties for capturing and storing solar energy. To this end, a synergistic protective etching strategy was developed to construct carbon superstructure‐supported V2O3 nanospheres (V2O3@CSs). The half‐metallic characteristics of V2O3, combined with the three‐dimensional superstructure assembled by ultrathin carbon nanosheets, established rapid charge transfer networks and robust framework for efficient and stable solar‐energy storage. Consequently, the V2O3@CSs photocathode delivered record zinc ion storage properties, including a photo‐assisted discharge capacities of 463 mAh∙g‐1 at 2.0 A∙g‐1 and long‐term cycling stability over 3000 cycles. Notably, the PZIBs assembled using V2O3@CSs photocathodes could be photorecharged without an external circuit, exhibiting a high photo conversion efficiency (0.354%) and photorecharge voltage (1.0 V). This study offered a promising direction for the direct capture and storage of solar energy.