Abstract: Lithium-manganese-oxides have been exploited as promising cathode materials for many years due to their environmental friendliness, resource abundance and low biotoxicity. Nevertheless, inevitable problems, such as Jahn-Teller distortion, manganese dissolution and phase transition, still frustrate researchers; thus, progress in full manganese-based cathode materials (FMCMs) has been relatively slow and limited in recent decades. Recently, with the fast growth of vehicle electrification and large-scale energy-storage grids, there has been an urgent demand to develop novel FMCMs again; actually, new waves of research based on FMCMs are being created. Herein, we systematically review the history of FMCMs, correctly describe their structures, evaluate the advantages and challenges, and discuss the resolution strategies and latest developments. Additionally, beyond FMCMs, a profound discussion of current controversial issues, such as oxygen redox reaction, voltage decay and voltage hysteresis in Li₂MnO₃-based cathode materials, is also presented. This review summarizes the effectively optimized approaches and offers a few new possible enhancement methods from the perspective of the electronic-coordination-crystal structure for building better FMCMs for next-generation lithium-ion batteries.

Key words: Energy storage, Lithium-ion batteries, Cathode materials, Manganese oxides