Advanced cathodes for potassium-ion battery

Potassium-ion battery (KIB) represents an emerging battery technology. Here in this review, we highlight the research progress of cathode materials for KIBs in recent 2 years. Statuses of four typical cathodes, layered metal oxides, polyanion compounds, Prussian blue analogs, and organic cathodes are discussed. Electrochemical performances of the cathode materials are improved through tailoring of the composition, microstructure, and surface modification of the electrodes. Regulating electrode-electrolyte interface also brings about prominent improvement in the rate capability and cycling stability of the cathodes. In particular, we speculate that both layered metal oxides and polyanion compounds should be of great application potential as cathodes for the future KIB full cells.