The surface coating strategy enhances the lithium storage performance of Ni3S2@PPy self-supporting as anode materials for lithium-ion batteries

Ni3S2 materials were innovatively in-situ grown on nickel foam by the one-step reflux method. Then, a polymer PPy conductive film was successfully coated on the surface of Ni3S2 materials by electrodeposition to prepare the self-supporting Ni3S2@PPy composites on nickel foam. The content of PPy on the surface of Ni3S2 materials was controlled by changing the number of cyclic voltammetry cycles in the electrodeposition process. Ni3S2@PPy has presented the best lithium storage performance when the number of cyclic voltammetry cycles is 1. After 100 cycles (50 mA g−1), the discharge capacity remained at 396.5 mAh g−1, and the charge transfer impedance decreased with the reaction. After PPy coating on the surface of Ni3S2 material, the problem of the rapid decline of Ni3S2 electrode capacity after 50 cycles was significantly improved, and enhanced the stability of the late cycle.