Prussian blue and its analogues as advanced supercapacitor electrodes

Abstract

Remarkable attention has been directed to Prussian blue (PB) and its analogues (PBA) as one of the most widely used metal-organic frameworks (MOFs) especially in the field of energy storage devices due to their fabulous features such as 3D open framework, high surface area, controllable distribution of pores and the low cost. Nevertheless, their depressed conductivity causes some insulation when being used as an electrode for supercapacitors leading to be restricted in further applications particularly the electronics. To the best of our knowledge, our review aimed primarily to give a total picture of the research that was done on utilizing PB and PBA for fabricating the electrodes of supercapacitor, studying their synthesis approaches in addition to the hybridization with other materials such as graphene, CNTs and conducting polymer. It also addresses the transformation of PB or PBA into other interesting nanostructures such as oxides, sulfides, and bicomponent of graphitic carbon nitride/metal oxides, as well. Furthermore, It exhibits various avenues for overcoming their disadvantages of bad cycle life, retention rate and not achieving the desired values of energy/power densities opening the door for enlarging the number of researches on their application as supercapacitors. According to the superb features of PB or PBA, we overviewed their synthesis designs and the utilization as electrodes for supercapacitors. For overcoming their drawbacks, this review suggests the key points for improving their electrochemical performance in the field of energy storage.