MWCNTs-GONRs/Co3O4@Ni(OH)2 core-shell array structure with a high performance electrode for supercapacitor

Abstract

A high-performance electrode for a supercapacitor was developed through a hydrothermal method that entailed the loading of multiwalled carbon nanotubes-graphene oxide nanoribbons (MWCNTs-GONRs) onto a Ni foam (NF) to create a substrate. A core shell array structure of Co3O4@Ni(OH)2 was added onto the substrate and grown. It anchored on the substrate, creating a MWCNTs-GONRs/Co3O4@Ni(OH)2 electrode. The electrode had good electrochemical properties such as a high specific capacitance (2654.7 F g−1), high charge-discharge rates, and a remarkable cycling stability. This was possibly a result of the synergistic effect of the 3D core shell array structure and the MWCNTs-GONRs. We also assembled asymmetric supercapacitors using MWCNTs-GONRs/Co3O4@Ni(OH)2 and active carbon as the positive and negative electrodes, respectively. The supercapacitor had a maximum energy density of 74.85 Wh kg−1 and high power density of 6.80 kW kg−1, with good cycling stability (83.31% capacitance retention after 10,000 cycles). The electrodes we developed and produced are promising and feasible for practical energy application requirements.