Hydrothermal synthesis of flower-like NiS–Ni3S4/stereotaxically constructed graphene composite for ultrahigh-rate sodium storage

Abstract

Flower-like NiS–Ni3S4/stereotaxically constructed graphene (NiS–Ni3S4/SCG) composite is synthesized by a hydrothermal method. When evaluated as anode materials for sodium ion battery, the material still retains a discharge capacity of 322.9 mA h g−1 with a coulombic efficiency near 100% after 2000 cycles at 10 A g−1, which corresponds to 69.2% of the 2nd discharge capacity. It is found that the SCG plays a positive role in improving electrochemical performance of NiS–Ni3S4 because it serves as an efficient 3D conductive network to enhance electronic conductivity and an elastic matrix to buffer volume expansion.