Construction of Bio-inspired Film with Engineered Hydrophobicity to Boost Interfacial Reaction Kinetics of Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries typically suffer from sluggish interfacial reaction kinetics and drastic cathode dissolution owing to the desolvation process of hydrated Zn2+ and continual adsorption/desorption behavior of water molecules, respectively. To address these obstacles, a bio-inspired approach, which exploits the moderate metabolic energy of cell systems and the amphiphilic nature of plasma membranes, is employed to construct a bio-inspired hydrophobic conductive poly(3,4-ethylenedioxythiophene) film decorating alpha-MnO2 cathode. Like plasma membranes, the bio-inspired film can selectively boost Zn2+ migration with a lower energy barrier and maintain the integrity of the entire cathode. Electrochemical reaction kinetics analysis and theoretical calculations reveal that the bio-inspired film can significantly improve the electrical conductivity of the electrode, endow the cathode-electrolyte interface with engineered hydrophobicity, and enhance the desolvation behavior of hydrated Zn2+. This results in an enhanced ion diffusion rate and minimized cathode dissolution, thereby boosting the overall interfacial reaction kinetics and cathode stability. Owing to these intriguing merits, the composite cathode can demonstrate remarkable cycling stability and rate performance in comparison with the pristine MnO2 cathode. Based on the bio-inspired design philosophy, this work can provide a novel insight for future research on promoting the interfacial reaction kinetics and electrode stability for various battery systems.

Automated summary

This study employs a bio-inspired approach to enhance the interfacial reaction kinetics and electrode stability of aqueous zinc-ion batteries. By constructing a bio-inspired hydrophobic conductive poly(3,4-ethylenedioxythiophene) film on the cathode, the electrical conductivity of the electrode is improved, the hydrophobicity of the cathode-electrolyte interface is engineered, and the desolvation behavior of hydrated zinc ions is enhanced, leading to improved overall interfacial reaction kinetics and cathode stability.