One-step microwave synthesis of self-supported CoSe2@NiSe2 nanoflowers on 3D nickel foam for high performance supercapacitors

Abstract

The work reports the fabrication of CoSe2@NiSe2 nanoflowers on nickel foam substrates via one-step microwave method, in which the Ni foam serves as a skeleton and a nickel source. The as-prepared CoSe2@NiSe2 nanoflowers display high capacitance value of 1434 F g−1 at the current density of 1 A g−1 and excellent cycling performance of 87.5% retention after 20,000 cycles at 10 A g−1. In addition, the supercapacitor device using CoSe2 @NiSe2 nanoflowers as the positive electrode and activated carbon (AC) as the negative electrode not only can exhibit wide voltage window of 1.6 V, but also deliver a maximum high energy density of 20.4 Wh Kg−1 at power density of 798 W Kg−1 and 86.6% of capacity retention after 20,000 cycles.