Material Design and Energy Storage Mechanism of Mn-Based Cathodes for Aqueous Zinc-Ion Batteries

Mn-based cathodes have been widely explored for aqueous zinc-ion batteries (ZIBs), by virtue of their high theoretical capacity and low cost. However, Mn-based cathodes suffer from poor rate capability and cycling performance. Researchers have presented various approaches to address these issues. Therefore, these endeavors scattered in various directions (e. g., designing electrode structures, defect engineering and optimizing electrolytes) are necessary to be connected through a systematic review. Hence, we comprehensively overview Mn-based cathode materials for ZIBs from the aspects of phase compositions, electrochemical behaviors and energy storage mechanisms, and try to build internal relations between these factors. Modification strategies of Mn-based cathodes are then introduced. Furthermore, this review also provides some new perspectives on future efforts toward high-energy and long-life Mn-based cathodes for ZIBs.