This book highlights the use/application of Vanadium Oxide as a Supercapacitor (SC) material using the electrodeposition method. The preparation methods, material characterization, and performance testing of VOx-based SC are thoroughly discussed. Electrolyte solutions from VCl3 and other metal precursors are used to form V3O5 electrodes on nickel foam (NF). The cathode can deliver a specific capacitance value of 5689 F/g. The work is improved by depositing V3O5 film on Ni(OH)2 to form a bilayer coating on NF substrate. Ni(OH)2 with a nano-sheet structure is used for the purpose of increasing the specific surface area of V3O5 layer which can achieve specific capacitance of 7500 F/g, the energy density of 167 Wh/kg, and the power density of 199 W/kg. After 10,000 charge-discharge cycles, the capacitance retention rate is 93%. Finally, a full cell SC is assembled using the bilayer electrode and active carbon. The asymmetric and symmetric full cells performed the specific capacitances of 390 F/g and 846 F/g, the energy densities of 286 Wh/kg and 170 Wh/kg, and the power densities of 1149 W/kg and 602 W/g, respectively. After 10,000 charge-discharge cycles, the capacitance retention rates of asymmetric and symmetric full cells are 97% and 95%, respectively.
