Progress in stabilizing zinc anodes for zinc-ion batteries using electrolyte solvent engineering

With the growing demand for scalable and cost-effective electrochemical energy storage systems, aqueous Zn-ion batteries (ZIBs) have attracted attention as cheap, efficient, and safe energy storage devices. However, practical applications of ZIBs are hampered by some challenges, such as Zn dendrite growth, corrosion, passivation, byproducts, cathodic dissolution, and harmful electrostatic interactions. These problems are directly associated with the electrolytes of ZIBs, which are in contact with both the cathode and anode. Recently, several studies have been conducted to optimize ZIB electrolytes. The electrolyte system includes the electrolyte and solvent. The solvent ensures stable operation of the electrolyte and improves the electrochemical efficiency of the cathode and anode, thus improving the electrochemical performance and stability of ZIBs. However, to date, the effect of solvents on the stability of Zn anodes remains unclear. Therefore, there is a need for detailed studies on solvents for ZIB electrolytes. Herein, we review the research progress in the stabilization of Zn anodes using various solvents, including alcohols, amines, acetonitrile, lipids, ethers, and dimethyl sulfoxide. In addition, we discuss the effects of different solvents on the stabilization mechanism of Zn anodes. Finally, the challenges and prospects of solvents used for stabilizing Zn anodes in electrolytes are analyzed, and future research directions for ZIB electrolyte dissolution are proposed. This review presents the research progress in the stabilization of Zn anodes using various solvents, including alcohols, amines, acetonitrile, lipids, ethers, and dimethyl sulfoxide.