Applied Surface Science, Vol.492, 746-755, 2019
A novel intercalation pseudocapacitive electrode material: VO(OH)(2)/CNT composite with cross-linked structure for high performance flexible symmetric supercapacitors
Fabrication of a novel electrode material with efficient storage mechanism is a desirable strategy to build a better supercapacitors. Herein, a novel intercalation pseudocapacitance material, VO(OH)(2)/CNT binary composite with cross-linked structure, is first successfully synthesized by a facile one-step hydrothermal method. This composite combines the intrinsic positive traits of each component, in which the synergistic efforts greatly enhance to achieve a considerable electrochemical performance. In the three-electrode system, VO(OH)(2)/CNT composite electrode exhibits a capacitance of 256 F.g(-1) (512C.g(-1)) at 0.5 A.g(-1) within the wide potential range of - 0.8-1.2 V. More remarkably, the VO(OH)(2)/CNT-based flexible symmetric supercapacitor delivers a high energy density of 32.08 Wh.kg(-1) at a power density of 63.65 W.kg(-1) in a large operating voltage of 2.2 V. As well as, it performs a well cycling stability that the capacitance retention is about 90% after 3000 cycles. For the factual application measurement, two devices in series can light red LED for 5 min after charging 100 s. This work enriches the exploration of vanadium oxyhydroxides' pseudocapaicitance performance, which is of great significance to the future application of vanadium oxyhydroxides in energy storage.
Keywords:Vanadium oxyhydroxide;VO(OH)(2)/CNT composites;Intercalation pseudocapacitance;Electrochemical properties;Supercapacitor electrode;Symmetric supercapacitor