A Self-Regulated Interface toward Highly Reversible Aqueous Zinc Batteries

Aqueous zinc batteries, that demonstrate high safety and low cost, are considered promising candidates for large-scale energy storage. However, Zn anodes suffer from rapid performance deterioration due to the severe Zn dendrite growth and side reactions. Herein, with a low-cost ammonium acetate (NH4OAc) additive, a self-regulated Zn/electrolyte interface is built to address these problems. The NH4+ induces a dynamic electrostatic shielding layer around the abrupt Zn protuberance to make the Zn deposition uniform, and the OAc- acts as an interfacial pH buffer to suppress the proton-induced side reactions and the precipitation of insoluble by-products. As a result, in the electrolyte with the NH4OAc additive, Zn anodes exhibit a long cycling stability of 3500 h at 1 mA cm(-2), an impressive cumulative areal capacity of 5000 mAh cm(-2) at 10 mA cm(-2), and a high Coulombic efficiency of approximate to 99.7%. A prototype full cell coupled with a NH4V4O10 cathode performs much better in terms of capacity retention than the additive-free case. The findings pave the way for developing practical Zn batteries.

Automated summary

By using a low-cost ammonium acetate (NH4OAc) additive, a self-regulated zinc/electrolyte interface is built to address the issues of rapid performance deterioration of zinc anodes. The additive induces a dynamic electrostatic shielding layer around the zinc protuberance, promoting uniform zinc deposition, and acts as an interfacial pH buffer to suppress side reactions and precipitation of insoluble by-products. These findings pave the way for practical zinc batteries.