Prussian-blue materials:Revealing new opportunities for rechargeable batteries

The demand to increase energy density of rechargeable batteries for portable electronic devices and electric vehicles and to reduce the cost for grid-scale energy storage necessitates the exploration of new chemistries of electrode materials for rechargeable batteries.The open framework-structure of Prussian-blue materials has recently been demonstrated as a promising cathode host for a variety of monovalent and multivalent cations with the tunable working voltage and discharge capacities.Recent progress toward the application of Prussian-blue cathode materials for rechargeable batteries is reviewed,with special emphasis on charge-storage mechanisms of different insertion species,factors influencing electrochemical performances,and possible approaches to overcome their intrinsic limitations.