Stable and enhanced electrochemical performance based on hierarchical core–shell structure of CoMn2O4@Ni3S2 electrode for hybrid supercapacitor

Abstract

Herein, accessible and low-cost CoMn2O4@Ni3S2 core–shell nanoneedle arrays have been prepared via a two-step approach comprised with hydrothermal-calcination and electrochemical deposition procedures, successfully. In the beginning, CoMn2O4 nanoneedle arrays took root on Ni foam to form the core skeleton and subsequently, hierarchical Ni3S2 nanosheets uniformly overlaid on the surface of CoMn2O4 nanoneedles shaping the shell structure. This CoMn2O4@Ni3S2 material was measured directly as supercapacitor electrode and presented high specific capacity of 192.2 mAh g−1 with current density of 1 A g−1. Besides, the electrode delivered outstanding cyclical stability as the capacity retention attained 90.2% after charge–discharge measurement at a large current density of 10 A g−1 for 10 000 cycles. Furthermore, a hybrid supercapacitor assembled by CoMn2O4@Ni3S2 cathode and activated carbon anode represented a high energy density of 51.2 Wh kg−1 with the power density of 1030.0 W kg−1. This work shows a facile and inexpensive procedure to design high-performance and strong-stability supercapacitor electrodes.