An organic-halide perovskite-based photo-assisted Li-ion battery for photoelectrochemical storage

Merging solar energy conversion and storage into a single device would improve the utilization of solar energy. Within such a device, the photoelectrochemical material is crucially important. Herein, we design a hybrid perovskite (DAPbI) that exhibits the favorable properties of fast charge transfer and CO redox sites for steady and reversible Li+ de/intercalation, and it can be used as a bifunctional cathode for an efficient photoinduced lithium-ion battery (LIB). The enhanced charge carrier lifetime of DAPbI (τCS/CR = 452.1/3905 ps, compared to the organic cation DAAQ where τCS/CR = 335.7/1291 ps) for solar harvesting and conversion and its abundant reversible redox activity for energy storage lay the foundations for efficient photoelectrochemical energy conversion and storage. Using DAPbI as a cathode, an integrated photo-assisted LIB is realized, with a 0.2 V reduction in charge voltage, a 0.1 V increase in discharge voltage, enhancements of 7.4% in roundtrip efficiency and 0.5% in photoelectrochemical energy storage efficiency, and an 11.3% reduction in input power and an 18% increase in output power. This work provides a direct and sustainable strategy to utilize solar energy through electrochemical energy storage, which may support prosperous developments in this domain.