▎ 摘　　要

NOVELTY - Hexagonal phase cobalt-graphene polycrystalline composite material where the metal cobalt has a stacked closely-packed sheet structure and graphite is sheet-shaped structure, has a carbon-cobalt mol ratio of 3:2. USE - Hexagonal phase cobalt-graphene polycrystalline composite material used as shielding. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of composite material comprising decomposition reducing of graphite oxide, adding 2-polyvinylpyrrolidone, ultrasonically dispersing to obtain brown solution, adding acetyl acetone cobalt and octadecylamine, raising the temperature of reaction, adding ethanol, rapidly reducing to room temperature and centrifuging to separate the reactants.