▎ 摘　　要

NOVELTY - Preparation of boron-nitrogen codoped three-dimensional structure of positive electrode material involves adding oxidized graphite into water to from oxidized graphene suspension, adding aqueous ammonia and sodium borohydride into the oxidized graphene suspension, adding obtained three-dimensional boron-nitrogen codoped graphene and Ketjenblack (RTM: highly electroconductive carbon black) into N-methylpyrrolidone to form a suspension, adding elemental sulfur to N-methylpyrrolidone to form a suspension, and stirring obtained two suspensions and centrifuging, washing and drying. USE - Preparation of boron-nitrogen codoped three-dimensional structure of positive electrode material used for lithium-sulfur battery. ADVANTAGE - The method provides boron-nitrogen codoped three-dimensional structure of positive electrode material in which nitrogen atoms and boron atoms in the boron-nitrogen codoped graphene can synergistically effect the adsorption of sulfur, and reduce shuffle effect, for improving cycle life of lithium-sulfur battery. DETAILED DESCRIPTION - Preparation of boron-nitrogen codoped three-dimensional structure of lithium-sulfur battery positive electrode material involves adding oxidized graphite into water and ultrasonically processing to from an oxidized graphene suspension, adding aqueous ammonia and sodium borohydride into the oxidized graphene suspension, transferring the suspension to hydrothermal kettle for hydrothermal reaction and washing with ethanol after completion of reaction and free-drying to obtain three-dimensional boron-nitrogen codoped graphene, adding the three-dimensional boron-nitrogen codoped graphene and Ketjenblack (RTM: highly electroconductive carbon black) into N-methylpyrrolidone and ultrasonically processing to form a suspension, adding elemental sulfur to N-methylpyrrolidone and ultrasonically processing until sulfur is completely dissolved to form a suspension, and uniformly stirring obtained two suspensions and slowly adding distilled water and centrifuging, washing and drying.