Self‐Assembled Protection Layer Induced by Bifunctional Additive for Reversible Aqueous Zinc Metal Battery

Abstract Aqueous zinc metal battery (AZMB) has received widespread attention due to the advantages of low cost and high safety. However, challenges of dendritic growth, hydrogen evolution reaction, and other side‐reaction impede the performance of the Zn anode. Herein, 4‐amino‐benzene‐sulfonic acid (ABSA) is proposed as an additive to the ZnSO₄ electrolyte for improving the performance of AZMB. Combined analyses of theoretical calculations and experiment results, ABSA assumes a pivotal function in constructing an adsorptive layer, facilitating the subsequent formation of a stable sulfur‐rich solid‐electrolyte interphase (SEI). Consequently, the SEI layer modulates the pathway of Zn²⁺ electrodeposition/dissolution and effectively hinders the deleterious growth of dendrites and unwanted side reactions. As a result, the Zn||Zn cells stably cycles for 2500 h at 1 mAh cm⁻²/1 mA cm⁻² and over 1000 h at 10 mAh cm⁻²/10 mA cm⁻². Significantly, the pouch cell of Zn||VO₂ can obtain the specific capacity of 151 mAh g⁻¹ after 100 cycles. This work may provide a new perspective for designing advanced electrolytes from the prospect of interface protection for the AZMB and other metal ion batteries.