Carbon decorated dendritic nickel sulfide coordinating with situ growth enabling hybrid supercapacitors with high specific energy and rate performance

Abstract

Three-dimensional (3D) carbon nanospheres and two-dimensional (2D) carbon layer co-decorated dendritic nickel sulfide (Ni3S2) is fabricated on a nickel foam via a two-step hydrothermal process. The carbon nanospheres with the diameters ranging from 150 to 200 nm embellished on the “treetop” and the carbon layer coated uniformly on the “trunk”, which enhance the capacitive performance of the composite electrode. Herein, the amorphous carbon can further provide more efficient electron conduction path for the electrodes. With its unique superstructure, the as-fabricated carbon decorated Ni3S2 electrode exhibits a high specific capacity of 297.2 mAh g−1 at 5 mA cm−2, remarkable cycling stability (84.1% of the initial capacity) for 10,000 cycles at 10 mA cm−1. The hybrid supercapacitor fabricates by carbon decorated Ni3S2 and active carbon, which achieves a high specific energy of 62.5 Wh kg−1 at a specific power of 241.5 W kg−1. The encouraging results of the electrode make it as a potential candidate for energy storage.