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

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Zinc-based batteries offer a low-cost, eco-friendly energy storage alternative.
• Key challenges include dendrite formation, passivation, and zincate migration, limiting performance and longevity.
• Developing stable zinc anodes is crucial for advancing rechargeable aqueous batteries.

Purpose of the Study:

• To address limitations in zinc anodes by creating anion-selective membranes.
• To enhance the stability and cycling performance of zinc anodes in aqueous electrolytes.
• To investigate the efficacy of electropolymerized films in mitigating dendrite formation and passivation.

Main Methods:

• Cathodic electropolymerization of poly-(vinylbenzyltrimethylammonium chloride) to form anion-selective membranes on zinc anodes.
• Modification of zinc anodes with the developed polymer films.
• Electrochemical testing, including fundamental tests and cycling of Zn-Ni batteries under harsh conditions.

Main Results:

• The modified zinc anode demonstrated significantly improved performance compared to bare zinc foil, even under extreme conditions.
• The polymer films effectively confined zincate ions, reducing passivation and shape change during cycling.
• Self-discharge was prevented, and contact between metallic zinc and active water was avoided.

Conclusions:

• Electropolymerized anion-exchange films offer a viable strategy for modifying zinc anodes.
• This water-based approach enhances the performance and stability of zinc anodes in alkaline electrolytes.
• The study represents a significant advancement toward the practical application of rechargeable zinc secondary aqueous batteries.