Assembly of the hierarchical MnO2@NiCo2O4 core-shell nanoflower for supercapacitor electrodes

Three-dimensional (3D) hierarchical MnO2@NiCo2O4 core-shell nanoflower in situ grown on the Ni-foam substrate has successfully prepared via a two-step hydrothermal process and calcination treatment, and the related properties of electrode materials for supercapacitors have also been investigated. The prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS). When the current density was 0.25 A/g, the specific capacitance of the MnO2@NiCo2O4 composite material could reach 634.37 F/g. The specific capacitance was 83.1% retention after 3000 cycles at 1 A/g, and the initial capacitance retention rate was 96.3%, showing good capacitance stability. It opens up a new way for the development of high-performance supercapacitor electrode materials.

Automated summary

A three-dimensional hierarchical MnO2@NiCo2O4 core-shell nanoflower was successfully prepared through a two-step hydrothermal process and calcination treatment, exhibiting excellent capacitance retention for supercapacitor electrode materials. The material showed high specific capacitance and good stability, opening up new avenues for high-performance supercapacitors.