High-Performance Solid-State Supercapacitors Based on V2O5/Carbon Nanotube Composites

Solid-state supercapacitors with high energy densities and excellent stabilities were developed by using V2O5/carbon nanotube (CNT) composites. A facile printing method was employed to prepare electrodes on indium tin oxide glasses with various V2O5/CNT ratios. The fabricated electrodes offer hierarchically porous structures, which provide short diffusion routes for the electrolyte and conducting pathways for electron transport. Moreover, the electrode is stabilized by a gel electrolyte, which enhances cycling stability by preventing dissolution of V2O5. The resulting hierarchically porous V2O5/CNT composites deliver a high energy density (1.47 mWh cm(-3)) and power density (0.27 W cm(-3)) with LiCl/polyvinyl alcohol electrolyte in a two-electrode configuration. Remarkably, the capacitance retention after 5000 cycles is more than 91% at a charge-discharge current density of 5 Ag-1.