Synthesis and properties of oxygen-deficient cobalt oxide nanocubes for supercapacitor application

The nano-dimensional morphologies were essential to improving the electrochemical performance of the supercapacitors. Oxygen-deficient hierarchical cobalt oxide nanocubes were fabricated in this study using a simple one-step hydrothermal technique. Each 3D-structured nanocube is composed of nanosized spherical grains with moderate oxygen vacancies, which can boost the number of electroactive sites (adsorption of OH─). The specific capacity of the Co3O4 nanocube electrode is 472.51 ± 1.8 C g─1 at a current density of 1 A g─1. It is worth revealing that it has excellent rate capability (65.54 % at 10 A g─1) and a capacity retention rate of 87.5 % after 14,000 cycles. It is believed that the synthesized Co3O4 nanocubes will offer interesting possibilities for high-performance supercapacitors.