V₂O₅/CdS Heterostructures for High-Rate Photo-Rechargeable Zinc-Ion Batteries

Photo-rechargeable batteries, capable of simultaneous solar energy harvesting and storage, attract significant research interest as next-generation autonomous power systems. The development of high-efficiency photoactive electrodes is highly desirable for achieving practical performance. Herein, we report V₂O₅/CdS composites for photo-rechargeable zinc-ion batteries, which enable efficient light-to-electricity-to-chemical energy conversion through effective separation of photogenerated electron-hole pairs. The photocell can be charged by light without an external power supply, achieving a light conversion efficiency of 0.99%. Notably, under a high current density (4.0 A g^-1), the capacity increases 24.1% to 301 mA h g^-1 after illumination compared to that in dark conditions. This work provides fundamental insights into the mechanisms enabling high-rate performance in photo-rechargeable zinc-ion batteries.