Manganese-based layered oxide cathodes for sodium ion batteries

Sodium-ion batteries (SIBs) have attracted enormous interests and considered to be an alternative to lithium-ion batteries (LIBs) because of the abundant natural resource and low-cost of sodium. Layered transition metal oxides appear to be potential cathode candidates for SIBs due to their plentiful structural diversity, fast diffusion of Na ions and feasibility for commercialization. In particular, Mn-based compounds have the advantages of low cost and high theoretical capacities. In this review, the recent progress of Mn-based layered oxides as cathode materials for SIBs are reviewed and summarized. A deep understanding of the relationship of the structural transition and electrochemical performance in layered oxide cathodes is provided. Moreover, the existing drawbacks are discussed, and several strategies are proposed to help mitigate these issues. Future perspectives are discussed to pave the way for the commercialization of such systems.