An Initial Review of the Status of Electrode Materials for Potassium-Ion Batteries

The status of room-temperature potassium-ion batteries is reviewed in light of recent concerns regarding the rising cost of lithium and the fact that room-temperature sodium-ion batteries have yet to be commercialised thus far. Initial reports of potassium-ion cells appear promising given the infancy of the research area. This review presents not only an overview of the current potassium-ion battery literature, but also attempts to provide context by describing previous developments in lithium-ion and sodium-ion batteries and the electrochemical reaction mechanisms discovered thus far. Perspectives and directions on the techniques available to characterize newly developed battery materials are also provided based on our experience and knowledge from the literature. It is hoped that through this review, the potential of potassium-ion batteries as a competitive energy-storage technology will be realised, and the accessibility and available knowledge of the techniques required to develop the technology will be made apparent.