Review of cathode materials for sodium-ion batteries

With the increasing maturity of lithium-ion battery (LIB) research and large-scale commercial application, the shortage of lithium resources has gradually emerged. Sodium-ion batteries (SIB) have become a potential choice for secondary battery energy storage systems due to their abundant resources, high efficiency, and ease of use. The cathode materials of sodium-ion batteries affect the key performance of batteries, such as energy density, cycling performance, and rate characteristics. At present, transition metal oxides, polyanion compounds, and Prussian blue compounds have been reported as cathode materials. This paper summarizes the classification, performance characteristics, and research progress of main cathode materials for sodium-ion batteries, and prospects the potential research directions.