▎ 摘　　要

NOVELTY - Method for preparing a tin dioxide/graphene composite material involves (i) immersing polished metal tin foil in water, bombarding the metal tin foil with a nanosecond pulsed laser beam with a laser flux of 600-1000 mJ pulse-1 cm-2 under 0 degrees C and ultrasonic conditions and taking out the remaining metal tin foil to obtain a tin oxide colloidal solution, (ii) ultrasonically dispersing graphene oxide powder in water to prepare a graphene oxide dispersion, (iii) slowly adding the tin oxide colloidal solution under vigorous stirring conditions to the graphene oxide dispersion and performing ultrasonic treatment to prepare a tin oxide/graphene oxide dispersion and (iv) performing hydrothermal reaction on the tin oxide/graphene oxide dispersion at 120-180 degrees C. USE - The method is useful for preparing a tin dioxide/graphene composite material used in a lithium ion battery cathode material (claimed). ADVANTAGE - The method realizes the uniform and tight anchoring of ultrafine tin dioxide quantum dots covalently bonded on the reduced graphene oxide sheet layer and can maintain the porous structure of the reduced graphene oxide when tin dioxide quantum dots are heavily loaded. DETAILED DESCRIPTION - Method for preparing a tin dioxide/graphene composite material involves (i) immersing polished metal tin foil in water, bombarding the metal tin foil with a nanosecond pulsed laser beam with a laser flux of 600-1000 mJ pulse-1 cm-2 under 0 degrees C and ultrasonic conditions and taking out the remaining metal tin foil to obtain a tin oxide of formula: SnOx colloidal solution, (ii) ultrasonically dispersing graphene oxide powder in water to prepare a graphene oxide dispersion, (iii) slowly adding the tin oxide colloidal solution under vigorous stirring conditions to the graphene oxide dispersion and performing ultrasonic treatment to prepare a tin oxide/graphene oxide dispersion and (iv) performing hydrothermal reaction on the tin oxide/graphene oxide dispersion at 120-180 degrees C. An INDEPENDENT CLAIM is included for the composite material prepared by the method.