Fundamentals and perspectives of electrolyte additives for aqueous zinc-ion batteries

Electrolyte additive as an innovative energy storage technology has been widely applied in battery field. It is significant that electrolyte additive can address many of critical issues such as electrolyte decomposition, anode dendrites, and cathode dissolution for the low-cost and high-safety aqueous zinc-ion batteries. However, there is a lack of systematic discussion on the features and functional mechanisms of electrolyte additives, which highlights the importance of a timely review with the academic perspective in this aspect. In this review, a comprehensive introduction of commonly used zinc-ion electrolyte additives is covered. Particularly, an in-depth and fundamental understanding on the disciplines and effects of electrolyte additives on electrolyte aspect, anode side, and cathode side has been expounded and evaluated. Due to the lack of systematic research in various electrolyte, anode and cathode issues, we have also highlighted the issues and pointed out the promising strategies for each aspect. The final section presents the potential directions and perspectives for further improvements and guidance of electrolytes and additives in aqueous zinc-ion batteries.