A novel bifunctional zinc gluconate electrolyte for a stable Zn anode

Aqueous zinc ions batteries, being developed rapidly as a promising type of energy storage devices, are troubled by dendrite growth on Zn anode surface. Herein, a novel bifunctional electrolyte-zinc gluconate, is employed as a new zinc salt for Zn-ion battery. This electrolyte possesses two important functions: acting as a nontoxic and even drinkable Zn salt to conduct stable and efficient electrochemical reactions of zinc plating/stripping, and supplying gluconate anions to construct artificial stable anionic interface for dendrite-free Zn deposition. Theoretical simulations and in-situ digital holography technology reveal the preferentially and horizontally adsorbed gluconate anions on metallic Zn to shield protuberances and fill concaves. As a result, an efficient and dendrite-free Zn anode interface can be simply achieved using 0.3 M zinc gluconate electrolyte without other electrolyte additives. This bifunctional zinc gluconate integrates cationic Zn2+ source and anionic gluconate interface, which provides a simple yet practical solution to stable and dendrite-free Zn anode.

Automated summary

A novel bifunctional electrolyte, zinc gluconate, is used as a zinc salt for zinc-ion batteries. This electrolyte acts as a nontoxic Zn salt and provides gluconate anions for constructing a dendrite-free Zn deposition interface. Theoretical simulations and experimental observations reveal that the gluconate anions preferentially adsorb on metallic Zn to fill concaves and shield protuberances, leading to an efficient and dendrite-free Zn anode.