Addressing the Zinc Corrosion Conundrum: The Vital Role of Resting-State Kinetics

Abstract

Aqueous zinc metal batteries (AZMBs) have emerged as a highly desirable system for grid storage applications due to low-cost, high-energy density, and safe operating conditions. While AZMB studies often focus on functional mitigation of dendrite formation and the hydrogen evolution reaction (HER), corrosion remains a more ambiguous yet crucial limiting factor in anode performance. Specifically, recent work points to persistent chemical corrosion as a major source of resting capacity loss in AZMBs. In this work, we present a wide-ranging mechanism for galvanic corrosion based on fundamental electrochemical thermodynamics and kinetics, highlighting the key roles of battery components, electrolyte conditions, and other contributing factors. Importantly, this mechanistic framework also applies when plating and stripping Zn on the anode, offering additional insight into the ever-elusive mechanistic origins of HER during those operating regimes. We then propose several promising avenues of inquiry and methods for further predicting, understanding, and mitigating corrosion in AZMBs.