Manganese hexacyanoferrate anchoring MnO2 with enhanced stability for aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (ZIBs) have provided new opportunities and challenges to the energy storage market due to their low price, high safety and environmentally friendly. Among the cathode materials of ZIBs, MnO2 appears to one of the most promising cathode for ZIBs owing to its high theoretical capacitance, abundant reserves, non-toxicity, and low cost. However, the poor cycling stability and rate performance have been the bottle-neck of MnO2 due to the slow electrochemical kinetics and severe structural damage during cyclic process. Herein, a new strategy is proposed to optimize the cycling stability and rate performance of the pristine MnO2 by a simple surface modification of manganese hexacyanoferrate (MnHCF). The anchored MnHCFs not only relieves the manganese dissolution during the continuous charge and discharge, but also introduces oxygen defects boosting the electrochemical kinetics of MnO2. The as prepared composite delivers a reversible specific capacity of 287 mA h g−1 at 0.1 A g−1 and maintains 87.1% of its initial capacity after 70 cycles.