Ultrathin nanosheet interconnected NixS6/Ni(OH)2 hybrid nanocages: successive self-sacrifice template fabrication and exceptional performance in supercapacitors

Low-cost and highly electroactive nickel-based materials are important electrodes for the development of supercapacitors. The precise modulation of the morphology and microstructure has been a crucial measure to further enhance the electrochemical performance. Herein, a three-dimensional porous nanocage NixS6/Ni(OH)2 hybrid formed by NixS6 nanoparticles anchored on Ni(OH)2 nanoflakes was creatively synthesized via a simple and scalable approach, which was based on two-time ion exchange reactions of the Mg(OH)2 precursor. Significantly, in asymmetric supercapacitors, the NixS6/Ni(OH)2 hybrid exhibits a high specific capacitance of 2726 F g−1 at a current density of 1 A g−1 and an excellent energy density of 31.31 Wh kg−1 at a power density of 62.56 W kg−1, which are superior to those of the currently reported nickel sulfide electrode materials. Compared with the nanoflower-like Mg(OH)2 and Ni(OH)2 precursors, the NixS6/Ni(OH)2 hybrid possesses hollow, abundant porous morphology and better electrical conductivity, which could provide a large contact surface area, shorter ion diffusion path and excellent charge transport, resulting in a dramatic improvement in electrochemical performance, making the NixS6/Ni(OH)2 hybrid a superb cathode material for supercapacitors.