Bi2O3 nanosheet-coated NiCo2O4 nanoneedle arrays for high-performance supercapacitor electrodes

Supercapacitors are a promising option for next-generation clean energy storage devices, although their capacitance must still be improved through an appropriate choice of electrode material. Herein, NiCo2O4 nanoneedles coated with Bi2O3 nanosheets are successfully prepared using a two-step hydrothermal process to produce electrodes that may be used for supercapacitors. The proposed electrodes are analyzed using both a range of experimental measurement techniques and density functional theory simulations. The NiCo2O4 nano -needles provide an ideal skeleton for improving specific surface area and present electrical active sites for the Faraday reaction, while Bi2O3 nanosheets have a great potential for use in supercapacitor applications. The proposed NiCo2O4@Bi2O3 electrode shows a high capacity of 766 F g(-1) at 1 A g(-1). In addition, an asymmetric supercapacitor based on a NiCo2O4@Bi2O3 positive electrode and activated carbon was produced, which pro-vided a working voltage of 1.6 V, achieved a high energy density of 24 Wh kg(-1) at 800 W kg( -1), and demonstrated excellent cycling stability (capacitance retention of 82 % after 10,000 cycles at 10 A g(-1)). These results demonstrate that the proposed NiCo2O4@Bi2O3 heterostructure exhibits potential for application in high-performance supercapacitors.

Automated summary

In this study, NiCo2O4 nanoneedles coated with Bi2O3 nanosheets were successfully prepared and investigated as electrode materials for supercapacitors. The proposed NiCo2O4@Bi2O3 heterostructure exhibited high capacitance, energy density, and cycling stability, showing great potential for application in high-performance supercapacitors.