Research Progress on Photo-assisted Metal-air Batteries: Mechanism, Challenges and Enhanced Performance Study
摘要
Metal-air batteries possess exceptional energy densities but are hindered by excessive overpotentials from sluggish oxygen reduction/evolution reaction (ORR/OER) kinetics. Integrating a photo-assisted mechanism offers a promising strategy to bypass these limitations by using photovoltage and photogenerated carriers to enhance catalytic kinetics. However, this coupling introduces critical challenges, including rapid carrier recombination, semiconductor photocorrosion, light-induced electrolyte degradation, and severe performance dependence on illumination. To address these critical bottlenecks, this review systematically elucidates the working mechanisms, system expansion, and performance control strategies for six types of photo-assisted metal-air batteries (Li, Zn, Na, Sn, Al and Fe), such as donor-acceptor engineering to broaden light absorption and facilitate charge transport, heterojunctions construction and defect engineering to suppress carrier recombination, diverse material systems and dual-photoelectrode strategy to boost catalytic kinetics, as well as the electrolyte engineering to improve its stability. Further, future perspectives are outlined, including in-depth analyses of dynamic mechanisms, the development of photostable electrodes, photo-resistant electrolyte systems, the regulation of all-weather performance and the establishment of standardized testing protocols, aiming to provide theoretical guidance for the rational design and engineering application of efficient and stable photo-assisted metal-air batteries.