Minireview and Perspectives on Functional Electrolyte Additives for Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) have been extensively recognized as the most viable large-scale energy storage devices due to their low cost, ecofriendliness, and high safety. Nevertheless, zinc anodes in conventional aqueous electrolytes suffer from harmful reactions, including zinc dendrites, hydrogen evolution reaction, and corrosion, resulting in a short cycle life of AZIBs. In recent years, versatile strategies have been performed to address these problems, among which engineering the electrolyte additive is regarded as a promising approach thanks to its advantages of simplicity and operability. Up to now, a great deal of work on electrolyte additives has been published; therefore, an in-depth and fundamental understanding of the mechanisms of additives is urgently needed. In this review, we comprehensively overview the functional role of the electrolyte additive in AZIBs, including regulating the solvation structure, altering the H-bond network, forming an adsorption layer, generating an electrostatic shielding effect, and constructing a solid electrolyte interphase. Lastly, some prospects for the future development of additives for advanced AZIBs are also suggested in this review.