Preparation of nanoporous nickelcopper sulfide on carbon cloth for high-performance hybrid supercapacitors

In this work, nanoporous nickel-copper sulfide on carbon cloth was successfully prepared via sulfurizing the nickel-copper carbonate hydroxide precursor through an anion exchange reaction. The as-fabricated electrode exhibits a high specific capacitance of 938.6 F g−1 at a current density of 1 A g−1 and good rate capability of 76% at 10 A g−1, as well as excellent flexibility. Charge storage analysis demonstrates that the combination of surface-controlled capacitive process and diffusion-controlled Faradaic process, both contribute to the total capacitance. In addition, the good performance of the nanoporous nickel-copper sulfide can be attributed to the possible higher conductivity and porous nanostructures which offers more active sites to yield extrinsic pseudocapacitance. A hybrid supercapacitor was assembled with nickel-copper sulfide as the positive electrode and nitrogen-doped graphene as the …