In Situ Monitoring of Dynamic Adsorption-Induced Interfacial Buffering Toward Highly Stable Zinc Metal Batteries

Abstract

Electrolyte regulation and electrode/electrolyte interface optimization are recognized as crucial strategies for mitigating parasitic reactions and enhancing zinc plating/stripping in zinc metal batteries. Despite their established importance, the underlying mechanisms of interface behavior and optimization remain elusive, especially in the absence of robust experimental characterization of adsorption-dominated approaches. Herein, in situ monitoring of interfacial adsorption effect is presented, employing a theoretically screened cyclen-based additive. The dynamic adsorption behavior in response to alternating electric fields is identified as pivotal in regulating the metal-electrolyte interfaces, as evidenced by a combination of in situ electrochemical quartz crystal microbalance (eQCM) measurements and constant-potential molecular dynamics simulation. Such dynamic adsorption provides a robust pH buffering effect at the zinc-metal anode interface, facilitating orderly and uniform zinc plating/stripping. Consequently, the electrochemical performance of zinc-based half cells and full cells is markedly enhanced. The findings offer comprehensive insights into the strategic development of functional electrolyte additives for aqueous zinc metal batteries.