Direct growth of MnCoSe2 nanoneedles on 3D nickel foam for supercapacitor application

Abstract

The present work reports the fabrication and performance studies of supercapacitors using MnCoSe2 nanoneedles-based electrodes. The MnCoSe2 nanoneedles-based supercapacitor electrode with a unique nanostructure exhibits an enhanced specific capacitance of 820 F g−1 and 386 F g−1 at 1 A g−1 in three-electrode and symmetric two-electrode configurations, respectively. The MnCoSe2 nanoneedles-based supercapacitor device has a specific energy of 54 Wh kg−1 at a specific power of 1 kW kg−1 and a superior cyclic stability of 95% retention after 10,000 charge-discharge cycles at 5 A g−1. Additionally, an asymmetric supercapacitor (ASC) device has been developed employing an anode based on rGO and a cathode based on MnCoSe2 nanoneedles. The asymmetric supercapacitor demonstrates an excellent gravimetric capacitance of 71 F g−1 at 1 A g−1 and an exceptional cycle life of 96% after 10,000 cycles. At a gravimetric power density of 227 W kg−1, the device produces a gravimetric energy density of 32 W h kg−1. The increased electrochemical performance can be ascribed to the three-dimensional nanowire-like surface morphology with a large electroactive site for enhanced redox reaction. Furthermore, high conductivity due to the presence of selenium provides rapid electron transfer and improves the electrochemical properties of supercapacitors. Accordingly, the present work indicates that the MnCoSe2 nanoneedles can be used as a potential electrode material for electrochemical energy storage applications.