Elimination of Zinc Dendrites by Graphene Oxide Electrolyte Additive for Zinc-Ion Batteries

Zinc-ion batteries have drawn tremendous attention in the electrochemical energy storage market because of their merits of high safety and low cost, however, the dendrites issue of zinc anodes remains a challenge. Herein, we developed a hybrid electrolyte with graphene oxide as an additive with the functions of promoting the uniform distribution of the electric field and reducing the nucleation overpotential of Zn2+, displaying a smooth zinc electrodeposition layer and reaction kinetics. The resultant zinc symmetric battery with graphene oxide additive affords a stable zinc anode which provided service for more than 650 h at 1 mA cm–2 and an exceptional cycle life of 140 h even at 10 mA cm–2. In addition, scanning electron microscopy images demonstrated that the deposition of zinc dendrites through the glass fiber separator was the reason for the battery short circuit. It is believed that the graphene oxide additive can remarkably improve the Coulombic efficiency (99.16%) of the batteries via stabilizing the Zn plating/stripping behavior and facilitating Zn2+ nucleation. Consequently, the full battery with graphene oxide electrolyte additive exhibited remarkable enhancements in rate performance and cyclability compared to the additive-free electrolyte. The hybrid electrolyte containing solid particles opens a chapter for designing advanced and durable zinc-ion batteries.