Recent Progress on the Performance of Zn-Ion Battery Using Various Electrolyte Salt and Solvent Concentrations

Rechargeable aqueous Zn-ion batteries (ZiBs) have attracted extensive attention in the field of large-scale electrical grid energy storage owing to their high level of safety, high volumetric energy density, and low cost. The usage of water as solvent facilitates the intrinsic properties. However, the battery performance is impeded by the narrow electrochemical stability window of the aqueous electrolyte, sluggish Zn2+-ion kinetics association with free water molecules, and undesired side reaction with cathode and anode materials. The viability of practical ZiBs largely depends on suitable electrolyte formulation. This review aims to provide a comprehensive understanding on the electrolyte formulation in association with basic characteristics, electrode/electrolyte interface mechanics, and their optimization strategies. The choice of suitable electrolyte salt, solvent, and other parameters related to the electrolyte along with their electrochemical performances are discussed. Finally, advanced strategies to modulate the suitable electrolyte and future perspectives are discussed to mitigate the issues for advanced ZiBs development.