Navigating highly reversible Zn metal anodes via a multifunctional corrosion inhibitor-inspired electrolyte additive

Uncontrolled dendrites growth and irreversible side reactions on the Zn anode have greatly shorten the lifespan of aqueous zinc-ion batteries (ZIBs), thereby hindering their application as promising energy storage devices. Herein, inspired by the use of corrosion and scale inhibitors in metal industry, sodium gluconate (SG) is proposed as a multifunctional electrolyte additive to improve the reversible plating/stripping behavior on Zn metal anodes by simultaneously modulating Zn anode-electrolyte interface and the Zn deposition behaviors. Combining theoretical calculations and experimental characterizations, it shows that SG can protect the Zn anode against the corrosion side reactions and suppress the random growth of dendritic Zn by absorbing on the Zn anode surface to form an artificial interface layer. Concomitantly, the gluconate anion reshapes the solvation shell of Zn2+, influencing the desolvation process of Zn2+ and disrupting the formation of active water. Furthermore, Na+ originating from SG suppresses the dendritic Zn development in the light of electrostatic shielding mechanism. Benefiting from these synergetic effects of SG additive, Zn metal anodes achieve exceptional reversibility with prolonged running lifetime and increased coulombic efficiency and the Zn||V2O5 full cell demonstrates outstanding cycle stability. This strategy is scalable and low-cost, developing a promising approach to advance high-performance ZIBs.