Fabrication of CNTs supported binary nanocomposite with multiple strategies to boost electrochemical activities

Electroactive materials with higher surface area, porous structure, higher conductivity, and self-supported design are considered promising candidates for electrochemical applications. The fabrication of an electrode material with a unique design having all the features mentioned above is a major challenge for electrochemical researchers. In this work, pristine CoS2 nanoparticles and CoS2/CNTs nanocomposite have been prepared and decorated directly on nickel foam (NF) using a two-step approach: hydrothermal and post-annealing, for energy storage applications. The CoS2/[email protected] electrode shows superior performance as it has a specific capacity (Csp) of 499.8 C g−1 @ 1 A g−1 and excellent cyclic stability of 90.8% after 6000 GCD cycles @ 12 A g−1. The CNTs-supported CoS2 sample displays a minimum capacitance loss of 13.5% by increasing the applied current density from 1 to 12 A g−1, demonstrating its excellent rate-capability. Furthermore, the EIS results show that the value of the charge transfer resistance (RCT) and the mass transfer resistance for CoS2 decreases after its nanocomposite formation with conductive CNTs. The exceptional electrochemical activity of the CoS2/[email protected] electrode has been attributed to the synergistic effect of its self-standing design, larger specific surface area, porous-nanostructure, and hybrid composition. The present study provides a new way of designing the electrode material with integrated electrochemical features.