Electrode reaction mechanisms in aqueous batteries: a comparative study and perspective on solid–solid versus solid–liquid–solid conversions

Aqueous batteries attract extensive attention because of their intrinsic safety, and electrode conversion mechanisms play a pivotal role in determining their electrochemical performance. This work systematically summarizes the fundamental principles of the two predominant reaction pathways, including solid-solid and solid-liquid-solid conversions, and presents a comparative analysis of their respective advantages and limitations in kinetic behaviors and structural regulations. Key factors affecting the stability and efficiency of these mechanisms are identified, along with a discussion of various regulatory strategies. Further, future research directions are proposed, including the construction of synergistic conversion systems, enhanced interfacial reaction control, and the development of advanced characterization techniques. This work aims to provide theoretical insights and research guidance for the rational design and mechanistic optimization of high-performance aqueous batteries.