Taurine-mediated dynamic bridging strategy for highly stable Zn metal anode

Abstract

Rampant dendrite growth and parasitic reactions are significant issues for the Zn metal anode. Herein, for the first time, we propose a dynamic bridging strategy to boost the reversibility of the Zn anode by introducing a chain taurine (TA) additive as a mediator. Elaborately designed electrochemical analysis and theoretical calculations reveal that TA can dynamically switch between inner Helmholtz plane (IHP) adsorption and modified solvation sheath due to the salt bridge interactions between the amphiphilic functional groups. TA adsorbed in IHP forms H2O-poor channels that preferentially facilitate the transport and desolvation of Zn2+ solvation sheaths containing TA, thereby inducing uniform nucleation and inhibiting H2O reduction. As a result, the Zn metal anode achieves excellent stability (over 4000 h) and low polarization voltage, both at high and low current densities (1–20 mA cm−2). This work provides a novel insight into electrolyte engineering for realizing high-performance aqueous Zn metal batteries (AZMBs).