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 K3Fe(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 K3Fe(CN)(6), while only 164 F g(-1) can be obtained in pure 1 KOH electrolyte. Furthermore, the VSe2 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.