Energy storage performance of 2D MoS2 and carbon nanotube heterojunctions in symmetric and asymmetric configuration

Excellent cyclic stability and fast charge/discharge capacity demonstrated by supercapacitors foster research interest into new electrode materials with 100% cycle life and high specific capacitance. We report an improvement in the electrochemical performance of MoS2/multiwalled carbon nanotubes (MWCNT) nanohybrid and intensively explored its performance in symmetric and asymmetric supercapacitor (ASC) assembly. The symmetric assembly of MoS2/MWCNT exhibits capacitance of around 274.63 F g−1 at 2 A g−1 with higher specific energy/power outputs (20.70 Wh kg−1/1.49 kW kg−1) as compared to the supercapacitor based on pristine MoS2 (5.82 Wh kg−1/1.07 kW kg−1). On the other hand, a unique all-carbon-based ASC assembled with MoS2/MWCNT and VSe2/MWCNT composite with K2SO4 as electrolyte delivers the highest energy density of 32.18 Wh kg−1 at a power density of 1.121 kW kg−1 with exceptional cycling stability and excellent retention of about 98.43% even after 5000 cycles. These outstanding results demonstrate the excellent electrochemical properties of both symmetric and asymmetric systems with high energy density and performance, which further enable them to be a potential candidate for supercapacitor applications.