Ni-doped Ni3S2 nanoflake intertexture grown on graphene oxide as sheet-like anode for high-performance lithium-ion batteries

Ni3S2 has become a promising anode material for lithium-ion batteries (LIBs) due to its favorable electrochemical conversion reaction, high theoretical specific capacity, and low cost. In this work, a nanoflake-assembled Ni-doped Ni3S2 sheet-like nanocomposite (Ni3S2–Ni–NF) was constructed using graphene oxide as the structure-directing agent by a simple two-step solvothermal reaction. The design of nanoflake subunit, sheet-like morphology, and Ni-doped Ni3S2 nanocomposite gains great promise for the application of LIBs by shortening the diffusion pathway of Li ions, improving the electrical connectivity as well as minimizing the electrode volume strain. As expected, the Ni3S2–Ni–NF nanocomposite exhibited excellent reversible capacities, high rate performance, and satisfactory cycling performance. For instance, reversible specific capacities of 741.8 mA h g−1 and 598.2 mA h g−1 can be retained after 120 cycles at current densities of 200 mA g−1 and 500 mA g−1, respectively. Furthermore, even at a very high current density of 1000 mA g−1, the discharge capacity remained as high as 497 mA h g−1.