▎ 摘　　要

NOVELTY - In-situ solid-phase synthesis of silicon-graphene spheroidal composite material involves mixing organic carbohydrate and transition metal inorganic salt with silica nanoparticles, dispersing obtained mixture in a crucible or boat in porcelain, then placing in a center of a sealed tube furnace, heating in mixed gas of argon and hydrogen, cooling, cleaning the cooled product using nitric acid 2-5 times, centrifuging and vacuum-drying at 60 degrees C. USE - In-situ solid-phase synthesis of silicon-graphene spheroidal composite material used as cathode material during assembling lithium ion battery (claimed). ADVANTAGE - The method enables synthesis of silicon-graphene spheroidal composite material having high electroconductivity. The generation of severe volume effect during cyclic process is prevented. The lithium ion battery using the silicon-graphene spheroidal composite material has high capacity and excellent cycle characteristics and rate performance. DETAILED DESCRIPTION - In-situ solid-phase synthesis of silicon-graphene spheroidal composite material involves mixing organic carbohydrate as carbon source and transition metal inorganic salt as catalyst precursor with silica nanoparticles having diameter of 1-1000 nm, controlling the mass ratio of carbon atoms in organic sugar to silicon material to 1:100-5:100 and mass ratio of transition metal inorganic salt to silicon material to 1:100-1:1000, dispersing obtained mixture in a crucible or boat in porcelain, then placing in a center of a sealed tube furnace, heating at 600-1000 degrees C for 1-6 hours in mixed gas of argon and hydrogen, cooling to room temperature, cleaning the cooled product using nitric acid 2-5 times, centrifuging and vacuum-drying at 60 degrees C. An INDEPENDENT CLAIM is included for assembling method of lithium ion battery, which involves using a negative electrode formed by coating a mixture of silicon-graphene spheroidal composite material, styrene-butadiene rubber, binder and solvent on a copper foil, heating and drying, forming a positive electrode by coating a mixture of 95 %mass lithium cobaltate positive-electrode active material, 2 %mass electroconductive carbon black, 3 %mass polyvinylidene fluoride and N-methylpyrrolidone on an aluminum foil, and a porous insulating film.