Electrochemically induced cationic defect in MnO intercalation cathode for aqueous zinc-ion battery

The Mn dissolution is a key issue in the application of high-energy-density manganese-based materials, but the use of Mn dissolution to unlock the electrochemical activity of electrode materials is rarely achieved. Here, an in-situ electrochemical approach has been developed for the activation of MnO by inducing Mn-defect, wherein the Mn defects are formed through a charge process that converts the MnO with poor electrochemical activities towards Zn2+ into high electrochemically active cathode for aqueous zinc-ion batteries (ZIBs). More importantly, this cathode exhibits an insertion/extraction mechanism without structural collapse during storage/release of Zn2+. The as-designed Zn/MnO battery delivers a high energy density of 383.88 Wh kg−1 at a power density of 135.6 W kg−1. The results demonstrate that the Mn-defect MnO would be a promising cathode for aqueous ZIBs, which is expected to be used in commercial large-scale energy storage. This work may pave the way for the possibility of using defect chemistry to introduce novel properties in electrode materials for high-performance aqueous ZIBs.