화학공학소재연구정보센터
Chemical Engineering Journal, Vol.358, 1529-1538, 2019
Boosting operating voltage of vanadium oxide-based symmetric aqueous supercapacitor to 2 V
Vanadium oxides have great potentials in high voltage symmetric supercapacitors, benefiting from the available multiple oxidation states of vanadium. In this work, charge storage in a wide potential window of - 1.1 to 0.9 V vs. SCE is achieve for vanadium oxide through vanadium valence tuning and incorporation in functionalized carbon nanowire array. The functionalized carbon nanowire array provides a good three dimensional conducive scaffold for the oxide nanowires, leading to high electron and ion transportation for the pseudo-capacitive materials. A high areal capacitance of 1.31 F cm(-2) is achieved for the obtained vanadium oxide electrode (at 1 mA cm(-2) in 5 M LiCl aqueous solution). It also displays good rate capability, demonstrating a quite high areal capacitance of 687 mF cm(-2) at 100 mA cm(-2). The assembled symmetric supercapacitor can be operate with a large voltage of 2 V and so can deliver a high volumetric energy density of 3.61 mWh cm(-3) at 0.01 W cm(-3). The supercapacitor also shows good stability, it can retain 91% of its capacitance after 10 000 galvanostatic charge-discharge cycles.