In-situ calcination of polyoxometallate-based metal organic framework/reduced graphene oxide composites towards supercapacitor electrode with enhanced performance

Polyoxometallate-based metal organic frameworks (POMOFs) have spurred great interest as a new paradigm for high-performance supercapacitor owing to the high specific surface area and reversible multi-electron redox process. Nevertheless, the poor charge transfer kinetics and chemical instability in alkali medium still remain a significant challenge. Herein, metal oxides derived from POMOFs are in suit decorated on conductive graphene layers to improve the POMOFs' performance. As a consequence, the calcination product fulfills an approving specific capacity of 178 F/g at 0.5 A/g and improved cycling stability of 94% capacity retention after 5000 cycles. The favorable performance is also authorized by the assembling asymmetrical supercapacitor, which delivers a maximum energy density and power density of 20.1 Wh/kg and 9071 W/kg. The unique strategy opens up a new avenue for the electrode materials of supercapacitors.