Metallic few-layered VSe2nanosheets: high two-dimensional conductivity for flexible in-plane solid-state supercapacitors

Metallic two-dimensional (2D) 1T-VSe2 with high conductivity and a large specific surface area is a promising electrode material for supercapacitors. Here, we use a facile chemical vapor deposition (CVD) method to prepare thin VSe2 nanosheets. A flexible in-plane solid-state supercapacitor is fabricated using the high-quality VSe2 nanosheets as the electrode material. The prepared supercapacitor presents an electrical double-layer capacitive behavior, and it has a high power density that is comparable with that of advanced graphene-based supercapacitors. The flexible supercapacitor also shows good mechanical stability to both bending and fatigue tests up to 10 000 cycles. This work provides a novel method for the fabrication of high-performance thin-film power sources, and paves the way for their application in soft thin-geometry devices.