We report the synthesis of mesoporous Ni3S2 nanorod arrays on three-dimensional Ni-graphene foams by a facile hydrothermal method for ultrahigh performance supercapacitors. The graphene foam facilitates unique morphological evolution during the hydrothermal process, from a mesoporous, monolithic structure to nanorod arrays of Ni3S2 with a hollow core-solid shell structure and to entirely solid nanorod arrays of Ni3S2. The Ni3S2 composite electrode delivers a remarkable specific capacitance of 1900 F g−1 at a current density of 1 A g−1, as well as promising cyclic stability with a high capacitance of 940 F g−1 after 2000 cycles at 10 A g−1 and 96% retention of its initial capacitance after the 2001st cycle at 5 A g−1. The symmetric supercapacitor prepared using the Ni3S2 electrodes under an optimum condition operates in a wide potential window of 0–1.6 V and offers a specific capacitance of 190.5 F g-1 at 4.5 mA cm−2 along with a maximum energy density of 67.7 W h kg-1. The promising electrochemical performance along with the facile synthesis strategy offers a new insight into developing high performance supercapacitors for emerging energy storage applications.

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