Improving stability and reversibility via fluorine doping in aqueous zinc–manganese batteries

Abstract

Constructing stable and reversible manganese-based cathode is one of the key technologies of aqueous Zn/MnO2 batteries (AZMBs). Herein, a rational strategy of fluorine doping is proposed to improve the reversibility and activity of MnO2. According to the strong bonding induced by high electronegativity of fluorine, the integrity of frameworks can stabilize, and the ion diffusion kinetics is promoted. Meanwhile, the strong ‘pinning effect’ of fluorine effectively retains the electrochemical activity and guides the reversible electrochemical behavior, which plays a critical role in improving both the cycle life and energy efficiency. As expected, a significant specific capacity of 300 mAh/g at 0.6 C and impressive stability over 1,200 cycles at 5 C are achieved without obvious decay. Such high stable Zn/F–MnO2 system may provide novel perspectives for designing high-performance AZMBs.