Recent Advances in Metallic Tin Anodes: An Emerging Field of Rechargeable Aqueous Batteries

Aqueous Sn batteries based on a metallic Sn anode are regarded as promising candidates for next-generation large-scale energy storage systems due to their low cost, high safety, and eco-friendly nature. Nonetheless, issues such as the formation of "dead Sn" due to excessively large deposition sizes and electrolyte-driven side reactions severely constrain the reversibility of the Sn anode, which hinders the further development of this emerging field. In response to these hurdles, numerous significant efforts have been proposed to tailor Sn plating/stripping chemistry in the past three years. Considering the lack of comprehensive summaries focused on recent advances for Sn anode stabilization, herein, we present a systematic review to deepen our understanding of Sn chemistry. This review commences by presenting the fundamental electrochemical working principle and associated challenges of Sn anodes in aqueous electrolytes, under either acidic or alkaline conditions. Subsequently, we systematically scrutinize recent research progress on optimization strategies for Sn anodes, focusing on electrolyte formulation modification and electrode structure design. Furthermore, specific cathode materials compatible with the Sn anode are discussed, classifying into conversion- and intercalation-types in view of their distinct reaction mechanism. Finally, suggestions and perspectives are provided for the future design of highly reversible Sn anodes. This work is anticipated to shed light on the construction of advanced aqueous Sn batteries.