▎ 摘　　要

NOVELTY - A nickel sulfide-nitrogen-doped graphene composite material comprises nickel sulfide content of 70-80%. USE - Nickel sulfide-nitrogen-doped graphene composite material for use in a lithium ion battery (claimed). ADVANTAGE - The nickel sulfide-nitrogen-doped graphene composite material has high charging/discharging capacity and high retention capacity. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing nickel sulfide-nitrogen-doped graphene composite material, which involves dispersing nickel carbonate and nitrogen-doped graphene in water, adding sulfur source and heating at 180-220 degrees C for 11-13 hours, followed by separating, washing and drying to obtain a finished product, where the mass ratio of nickel carbonate and nitrogen-doped graphene is 1:0.2-1:2.