Opportunities and challenges for aqueous metal-proton batteries

Benefiting from fast proton diffusion dynamics, aqueous metal-proton batteries (AMPBs) comprising a proton-storage cathode and a metal anode serve as an emerging system with tremendous potential for high-power energy-storage devices. However, there have been few reports on how to systematically design and construct high-performance AMPBs. Herein, we describe the common proton-storage electrode materials and discuss their desirable features, including high stability in proton insertion/extraction, high compatibility in mild acidic electrolytes, and abundant proton-storage sites. In addition, common problems plaguing aqueous electrolytes and metal anodes in AMPBs, such as electrode corrosion, metal dendrite formation, and hydrogen evolution, are discussed in detail. Finally, we conclude that stable electrolyte/electrode interfaces and homogeneous ion distributions are crucial to the charging/discharging processes. This review would provide guidance on how to rationally design AMPBs and shed light on future developments.

Automated summary

This study describes common proton-storage electrode materials for AMPBs and discusses their desirable features, as well as common problems plaguing aqueous electrolytes and metal anodes in AMPBs. The crucial importance of stable electrolyte/electrode interfaces and homogeneous ion distributions in charging/discharging processes is highlighted.