Coupled Photochemical Storage Materials in Solar Rechargeable Batteries: Progress, Challenges, and Prospects

Solar rechargeable batteries (SRBs), as an emerging technology for harnessing solar energy, integrate the advantages of photochemical devices and redox batteries to synergistically couple dual-functional materials capable of both light harvesting and redox activity. This enables direct solar-to-electrochemical energy storage within a single system. However, the mismatch in energy levels between coupled photochemical storage materials (PSMs) and the occurrence of side reactions with liquid electrolytes during charge-discharge cycles lead to a decrease in solar energy conversion efficiency. This impedes the advancement of SRBs. This review comprehensively discusses of the latest advancements in PSMs, which are crucial for designing advanced SRBs. It delves into an extensive discussion of the design criteria for dual-functional photochemical storage cathodes (PSCs) and elucidates the operational mechanism of SRBs. Additionally, it further discusses the performance, efficiency, and long-term cycle stability of SRBs in relation to photoelectronic and photothermal mechanisms. Finally, an outlook on primary challenges and prospects that SRBs will encounter is provided to offer novel insights for their technological advancement.