Electrochemical Activation to Unlock the Potential of Manganese Sulfide As High-Performance Cathodes for Rechargeable Aqueous Zn-Ion Batteries

Abstract

The broad implementation of review energy to the electrical grid requires the development of highly safe and low-cost batteries. The rechargeable aqueous Zn/MnO2 batteries have been considered a promising candidate for large-scale energy storage devices. However, MnO2 cathode suffers from poor capacity and cyclability due to the inferior utilization of electrochemically active surface area and manganese dissolution during cycling. Herein, we report a compelling manganese oxide cathode for aqueous rechargeable Zn ion batteries, which was derived from MnS precursor through in situ electrochemical activation process. Such electrochemical activation approach induces abundant defects and active sites to unlock the electrochemical reactivity of MnS derived oxide cathode (MnS-EDO). Benefiting from the large electrochemically active areas and fast ion diffusion kinetics, MnS-EDO exhibits high capacity utilization and outstanding long-term cyclability. At 300 mA g-1, a high specific capacity of 335 mAh g-1 can be achieved after 100 cycles. At 3000 mA g-1, an exceptional cycling performance can be maintained over 4000 cycles without obvious capacity loss. Moreover, the underlying electrochemical mechanisms are systematically investigated. This work opens a new approach for the future development of high-performance manganese oxide-based cathodes.