Review on recent advances of inorganic electrode materials for potassium-ion batteries

Rechargeable potassium-ion batteries (PIBs) have great potential in the application of electrochemical energy storage devices due to the low cost, the abundant resources and the low standard reduction potential of potassium. As electrode materials are the key factors to determine the electrochemical performance of devices, relevant research is being carried out to build high-performance PIBs. In recent years, significant progress has been made in the study of the design of inorganic electrode materials. Herein, we review the cathode materials (Prussian blue and its analogues, layered oxides and polyanionic compounds) and the anode materials (antimony-based, selenium-based and bismuth-based compounds). On the basis of previous work, the structural design principles for improving the performance of electrode materials are reasonably summarized. At the same time, the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.