Enhanced the electrochemical performance and stability of supercapattery device with carbon nanotube/cobalt‐manganese sulfide‐based composite electrode material

Supercapattery devices have gained extraordinary attention due to high power and energy densities with excellent cycle stability compared to conventional storage devices. Herein, the cobalt manganese sulfide (CoMnS) is synthesized using the hydrothermal method, and designed the supercapattery device. Further, carbon nanotubes (CNTs) are used to make a composite with CoMnS and measure the electrochemical characteristics. A high value of specific capacity (Qs = 934.7 C/g) is estimated at a current density of 1.5 A/g in the CoMnS/CNT composite sample, which is higher than the reference sample. Besides, the asymmetric supercapattery device is designed to measure the real device. In CoMnS/CNT//AC supercapattery device, the conceived value of the Qs is 137.06 C/g with an extraordinary energy density of 38.4 Wh/kg and power density of 1120 W/kg. A reliability test is conducted to explore stability, and the device is subjected to 10 000 charging/discharging cycles and observed that 84% of the nominal capacity is maintained. The composite of sulfides with CNTs provides a unique platform to design a unique and novel electrode material for supercapattery and other energy storage devices.