Rubik’s cube-like Ni3S4/CuS2 nanocomposite for high-performance supercapacitors

Transition metal sulfide, a promising electrode material using for supercapacitors, has attracted broad attention. In this work, a Rubik’s cube-like Ni3S4/CuS2 nanocomposite has been successfully fabricated by vulcanizing the Ni(OH)2/CuS2 precursor prepared via sacrificial template method. The obtained Ni3S4/CuS2 have a high specific capacitance of 888 F g−1 at 1 A g−1 and superior cycling stability of 83.33% retention after 2000 circles. Furthermore, the asymmetric supercapacitor, based on the Ni3S4/CuS2 nanocomposite and the reduced graphene oxide, shows an ultra-high energy density of 49.68 Wh kg−1 at the power density of 400 W kg−1. •A Rubik’s cube-like Ni3S4/CuS2 nanocomposite has been successfully fabricated by vulcanizing the Ni(OH)2/CuS2 precursor.•Ni3S4/CuS2 exhibited a specific capacity of 888 F g−1 in 2 M KOH aqueous solution at 1 A g−1 current density.•The assembled asymmetric Ni3S4/CuS2//RGO shows a high energy density of 49.68 Wh kg−1 at a power density of 400W kg−1.