Stable and enhanced electrochemical performance based on hierarchical core-shell structure of CoMn₂O₄@Ni₃S₂electrode...

Herein, accessible and low-cost CoMn₂O₄@Ni₃S₂core-shell nanoneedle arrays have been prepared via a two-step approach comprised with hydrothermal-calcination and electrochemical deposition procedures, successfully. In the beginning, CoMn₂O₄nanoneedle arrays took root on Ni foam to form the core skeleton and subsequently, hierarchical Ni₃S₂nanosheets uniformly overlaid on the surface of CoMn₂O₄nanoneedles shaping the shell structure. This CoMn₂O₄@Ni₃S₂material was measured directly as supercapacitor electrode and presented high specific capacity of 192.2 mAh g^-1with 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^-1for 10 000 cycles. Furthermore, a hybrid supercapacitor assembled by CoMn₂O₄@Ni₃S₂cathode and activated carbon anode represented a high energy density of 51.2 Wh kg^-1with 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.