Zwitterion Intercalated Manganese Dioxide Nanosheets as High‐Performance Cathode Materials for Aqueous Zinc Ion Batteries

Abstract

AbstractIn this study, a novel approach is introduced to address the challenges associated with structural instability and sluggish reaction kinetics of δ‐MnO2 in aqueous zinc ion batteries. By leveraging zwitterionic betaine (Bet) for intercalation, a departure from traditional cation intercalation methods, Bet‐intercalated MnO2 (MnO2‐Bet) is synthesized. The positively charged quaternary ammonium groups in Bet form strong electrostatic interactions with the negatively charged oxygen atoms in the δ‐MnO2 layers, enhancing structural stability and preventing layer collapse. Concurrently, the negatively charged carboxylate groups in Bet facilitate the rapid diffusion of H+/Zn2+ ions through their interactions, thus improving reaction kinetics. The resulting MnO2‐Bet cathode demonstrates high specific capacity, excellent rate capability, fast reaction kinetics, and extended cycle life. This dual‐function intercalation strategy significantly optimizes the electrochemical performance of δ‐MnO2, establishing it as a promising cathode material for advanced aqueous zinc ion batteries.