Stabilizing Zinc Anodes with Water-Soluble Polymers as an Electrolyte Additive

HighlightsWhat are the main findings?Different water-soluble polymers can be used as electrolyte additives.PAA exhibits stable cycling for more than 360 h at 5 mA cm−2, 2 mA h cm−2.What are the implications of the main findings?PAA exhibits an optimum performance.PAA additive can inhibit hydrogen evolution, dendrite growth, and corrosion on the zinc anode.Water-induced corrosion and zinc dendrite formation seriously disrupt the Zn plating/stripping process at the anode/electrolyte interface, which results in the instability of the Zn metal anode in aqueous zinc-ion batteries. To address the issues of the zinc metal anode, three water-soluble polymers with different hydrophilic groups—polyacrylic acid (PAA), polyacrylamide (PAM), and polyethylene glycol (PEG)—were designed as electrolyte additives in ZnSO4electrolytes. Among them, the PAA-based system exhibited an optimal electrochemical performance, achieving a stable cycling for more than 360 h at a current density of 5 mA cm−2with an areal capacity of 2 mA h cm−2. This improvement could be attributed to its carboxyl groups, which effectively suppresses zinc dendrite growth, electrode corrosion, and side reactions, thereby enhancing the cycling performance of zinc-ion batteries. This work provides a reference for the optimization of zinc anodes in aqueous zinc-ion batteries.