▎ 摘　　要

NOVELTY - Graphene modified lithium iron phosphate quantum dot composite material is prepared using trivalent iron salt and graphene oxide as raw materials, preparing graphene-modified ferroferric oxide quantum dot composite precursor by liquid phase method, adding small organic carbon source, covering surface of precursor with an amorphous carbon layer after hydrothermal treatment and calcination in order, introducing lithium ions and phosphate by solvothermal process and calcining. USE - Graphene modified lithium iron phosphate quantum dot composite material for preparing positive electrode sheet of lithium ion battery (claimed). ADVANTAGE - The material overcomes defect of poor electrical conductivity of existing lithium iron phosphate materials and poor large-rate charge-discharge performance of lithium-ion batteries and is economical. The carbon-coated lithium iron phosphate quantum dots with extremely small particle size of more than 10 nm are anchored on surface of graphene to form special amorphous carbon layer/lithium iron phosphate quantum dot layer/graphene layer sandwich structure. The lithium-ion battery has excellent charge and discharge cycle performance, and mass specific capacity is greater than 120 mAh.g-1 at 20C rate. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of graphene modified lithium iron phosphate quantum dot composite material; and (2) use of graphene modified lithium iron phosphate quantum dot composite material for preparing positive electrode sheet of lithium ion battery.