Bifunctional MA3Bi2I9 towards solar energy conversion and storage for all-solid-state photo-rechargeable battery

Recent endeavors have concentrated intensively on the integration and storage of solar energy within a singular apparatus. However, at present, these apparatuses are confronted with issues such as complicated fabrication processes, complex structures, and electrolyte leakage. In this study, an all-solid-state photo-rechargeable battery is presented, utilizing TiO2 as the photoanode, MA3Bi2I9 as the photoelectric conversion and energy storage active material layer, and Pt as the counter electrode. The assembled device can remain an open-circuit voltage of 0.35 V in the dark state. Devices connected in series can power a LED for up to 2 min. Furthermore, this photorechargeable battery demonstrates commendable stability over a storage period of 60 days under ambient conditions. Simultaneously, electrochemical analyses corroborate that the charge-discharge mechanism of the device is intimately associated with the redox processes of Bi ions. This study proposes novel approaches for the design of innovative energy devices that integrate photovoltaic charging and energy storage.