Abstract:
VO2 is a low band-gap semiconductor with relatively high conductivity among transition metal oxides,
which makes it an interesting material for supercapacitor electrode applications. The performance of VO2
as supercapacitor electrode in organic electrolytes has never been reported before. Herein, twodimensional nanosheets of VO2 are prepared by the simultaneous solution reduction and exfoliation
from bulk V2O5 powder by hydrothermal method. A specific capacitance of 405 Fg 1 is achieved for VO2
based supercapacitor in an organic electrolyte, in three electrode configuration. The symmetric capacitor
based on VO2 nanosheet electrodes and the liquid organic electrolyte exhibits an energy density of
46Wh kg 1 at a power density of 1.4 kWkg 1 at a constant current density of 1 Ag 1
. Furthermore,
flexible solid-state supercapacitors are fabricated using same electrode material and Alumina-silica
based gel electrolyte. The solid-state device delivers a specific capacitance of 145 Fg 1 and a device
capacitance of 36 Fg 1 at a discharge current density of 1 Ag 1
. Series combination of three solid state
capacitors is capable of lighting up a red LED for more than 1 minute.
