Electrodeposition of Zinc from Alkaline Electrolytes Containing Quaternary Ammonium Salts and Ionomers: Impact of Cathodic-Anodic Cycling Conditions

Dendrite suppression capabilities are key factors for the practical deployment of rechargeable Zn-based batteries. We propose a systematic electrochemical investigation, accompanied by SEM imaging, of the impact of representative quaternary ammonium (QA) salts and ionomers on Zn electrodeposition. Both cathodic and anodic processes were considered, because insoluble corrosion products can impact subsequent electrodeposition during cycling. We used simple cyclic voltammetry methods and developed a framework for their quantitative interpretation in terms of physically legible descriptors. QA-based additives tend to suppress the accumulation of anodic products, favoring symmetric cathodic and anodic activation. Poly di-allyl di-methyl ammonium chloride (PDADMAC), a polymer with limited cathodic reactivity, was found to be a promising additive that minimizes cathodic and anodic irreversibility and stabilizes mass transport, possibly owing to the formation of a single-ion conducting cathodic film.