VSe2/carbon-nanotube compound for all solid-state flexible in-plane supercapacitor

Abstract

Two-dimensional (2D) metallic transition-metal dichalcogenide (MTMD)/carbon-nanotube (CNT) compounds are competitive electrode materials for solid-state flexible in-plane supercapacitors, resulting from the synergistic effect of the large specific surface area of 2D MTMDs and the excellent mechanical properties of the CNT. In this paper, the high-quality VSe2/CNT electrode material is prepared by the one-step chemical vapor deposition (CVD) method. The CVD method offers a facile and safe way to synthesize a pure VSe2/CNT compound. The VSe2 nanosheets are vertically grown on the surface of the CNT cluster. The vertical configuration of the VSe2 nanosheets on the conductive CNT cluster takes full advantage of the large specific surface area of the VSe2 nanosheets to store charges. The ductile and conductive CNT cluster offers good mechanical and electrical connections to the VSe2 nanosheets. The VSe2/CNT compound is applied as the electrode material of a solid-state flexible in-plane supercapacitor which achieves a specific area capacitance of 1854 μF/cm2 and stable cycling stability, ∼7% degradation after 10 000 times of current cycling. The VSe2/CNT also presents a desirable mechanical stability, and ∼ 90% capacitance is retained after bending up to 40°. This work promotes the application of 2D MTMD compounds in the field of energy storage and wearable devices.