The role of carbon nanotubes in enhanced charge storage performance of VSe 2 : experimental and theoretical insight from DFT simulations.

Herein, we report the hybrid structure of metallic VSe 2 and multi-walled carbon nanotube (MWCNT) based hybrid materials for high performance energy storage and high power operation applications. The dominance of capacitive energy storage performance behaviour of VSe 2 /MWCNT hybrids is observed. A symmetric supercapacitor cell device fabricated using VSe 2 /80 mg MWCNT delivered a high energy density of 46.66 W h kg -1 and a maximum power density of 14.4 kW kg -1 with a stable cyclic operation of 87% after 5000 cycles in an aqueous electrolyte. Using density functional theory calculations we have presented structural and electronic properties of the hybrid VSe 2 /MWCNT structure. Enhanced states near the Fermi level and higher quantum capacitance for the hybrid structure contribute towards higher energy and power density for the nanotube/VSe 2 .