Enhanced supercapacitive energy storage performance of metal organic frameworks derived shuttle-like vanadium selenide in K3Fe(CN)6-based redox electrolyte

Shuttle-like vanadium selenide was prepared via carbonizing the vanadium-based metal organic frameworks for supercapacitors. Its morphology and structure were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and N 2 adsorption–desorption isotherm. Its electrochemical performance was investigated by cyclic voltammetry and galvanostatic charge–discharge test in three electrode configurations for supercapacitor. Compared with those in pure KOH electrolyte, the supercapacitive performances can be greatly enhanced when adding a certain amount of K 3 Fe(CN) 6 in KOH. A high specific capacitance of 512 F g −1 can be achieved at a scan rate of 0.2 mV −1 in 1 M KOH + 0.02 M K 3 Fe(CN) 6 , while only 164 F g −1 can be obtained in pure 1 KOH electrolyte. Furthermore, the VSe 2 also exhibits stable long-term cycling, 84.7% capacitance retention after 6500 cycles at a current density of 2 A g −1 . Those results provide a facile yet effective method for high performance energy storage devices.