Insight into aqueous electrolyte additives: unraveling functional principles, electrochemical performance, and beyond†

Aqueous electrolyte additives are considered one of the most promising agents for improving the cycling stability and practicality of aqueous zinc-ion batteries (AZIBs) due to their multiple functions, low cost, and easy operation. The application of these electrolyte additives could significantly suppress the corrosion reaction, dendrite growth, and the hydrogen evolution reaction originating from the zinc anodes. In light of the intensive research of electrolyte additives and the significant progress that have been made in recent years, this review will focus on the mechanism and nature behind the improved performance contributed by the additives. A comprehensive overview of the origins of the challenges above will be presented firstly. Furthermore, the basic function principles of most reported additives are summarized and categorized, aiming to induce a deep and logical consideration of the use of the electrolyte additives in practical or large capacity cells. Finally, this review outlines the prospective advancement of electrolyte additives, inspiring the application of advanced characterization techniques in enhancing the understanding of AZIBs and laying the groundwork for the possibility of commercialization of AZIBs.