Improving Zn Anode Cyclability in Alkaline Electrolytes with Electropolymerized Anion-Selective Film

Zinc-based batteries are considered a promising alternative for sustainable energy storage due to their low cost and environmental benefits. However, challenges such as dendrite formation, passivation, and zincate migration hinder their performance and long-term stability. In this study, we address these issues by developing anion-selective poly(vinylbenzyltrimethylammonium chloride) membranes via cathodic electropolymerization to modify zinc anode. These films were designed to confine zincate ions and reduce passivation and shape change during cycling while preventing self-discharge and avoiding the contact between metallic Zn and active water. Under extremely harsh testing conditions (closed cell, small amount of electrolyte), the Zn anode is modified with electropolymerized polymer and shows significantly improved performance compared to bare Zn foil. The highly rechargeable Zn anode reported is an important step toward practical Zn secondary aqueous batteries. This work proposes an improved, water-based strategy for zinc anode modification with electropolymerized anion-exchange films that improves the performance in alkaline electrolytes, as demonstrated by fundamental electrochemical tests and cycling of Zn–Ni batteries.