Cobalt-based oxides are promising candidates for supercapacitor electrodes, but their practical application is often hindered by poor electrical conductivity, limited ion diffusion, and insufficient cycling stability. Herein, we present a novel strategy to improve the electrochemical performance of Co3O4 by growing grape-like Co3O4 clusters on a nitrogen-doped carbon framework consisting of nitrogen-doped graphene oxide (NGO) and nitrogen-doped carbon nanotubes (NCNTs) through a controlled hydrothermal process. The nitrogen functionalities in the carbon matrix not only facilitate strong interactions between the NGO and NCNTs but also provide abundant nucleation sites for the growth of Co3O4 spinel nanoparticles (30–50 nm). This unique structure promotes an efficient electron conduction and ion transport network, which significantly improves the electrochemical performance of the Co3O4 electrode. The Co3O4@NGO/NCNT ternary nanocomposite, containing 39% Co3O4 and featuring a high specific surface area of 162 m2 g−1, delivers a specific capacitance of 269 F g−1 at 1 A g−1 and maintains 82% of its capacitance when the current density increases to 10 A g−1. Notably, the nanocomposite demonstrates outstanding cycling stability, with negligible capacitance decay after 2000 charge–discharge cycles at a current density of 5 A g−1, underscoring its excellent electrochemical robustness. This Co3O4@NGO/NCNT nanocomposite represents a promising and efficient material for high-performance supercapacitor electrodes.
Liu et al. (Mon,) studied this question.