Fabrication of rationally designed CNTs supported binary nanohybrid with multiple approaches to boost electrochemical performance

An electrode with a three-dimensional spatial framework, good electrical conductivity, higher specific surface area, porous structure, and binder-free design is considered to be most ideal for supercapacitor applications. It is a major challenge for the electrochemical researchers to manufacture an electrode material with a rational design that exhibits all of the above features. In this context, we have fabricated nanostructured Co3O4 and its nanohybrid with carbon nanotubes via a single-step hydrothermal route. A binary nanohybrid sample directly decorated on the three-dimensional nickel foam was used as a binder-free electrode for supercapacitor applications. Our electrode fabricated with multiple approaches showed an excellent specific capacitance of 852 Fg−1 @ 1 Ag−1 and the best rate capability of 89.7% @ 12 Ag−1. Moreover, the nanohybrid electrode possessed outstanding cyclic stability of 91.6% retention after 7000 Galvanostatic charge–discharge cycles. The superior electrochemical activity of the binary nanohybrid is benefiting from its porous nanostructure, hybrid composition, higher specific surface area (145 m2g−1), good electrical conductivity (3.3 × 10−2 Sm−1), and binder-free design. Application study results suggested that multiple approaches for preparing the supercapacitor electrode were constructive and encouraging.