▎ 摘　　要

NOVELTY - Preparation of graphene film-coated lithium-iron phosphate anode material involves dispersing lithium source, iron source and chelate phosphine source in water, adding aqueous graphene oxide solution, mixing uniformly, performing hydrothermal reaction at 150-260 degrees C, obtaining lithium-iron phosphate anode material precursor and sintering the precursor in a protective atmosphere. The chelated phosphine source is chosen from e.g. risedronic acid, 2-hydroxyphosphonoacetic acid, pamidronic acid, alendronic acid, ibandronic acid, zoledronic acid and 2-aminoethylphosphonic acid. USE - Preparation of graphene film-coated lithium-iron phosphate anode material (claimed) used for lithium-ion battery. ADVANTAGE - The method enables efficient preparation of graphene film-coated lithium-iron phosphate anode material having core/shell structure, by simple process. The anode material improves energy density, charge-discharge characteristics and cycle performance of the lithium-ion battery. The raw materials used in the preparation method are economical. DETAILED DESCRIPTION - Preparation of graphene film-coated lithium-iron phosphate anode material involves dispersing lithium source, iron source and chelate phosphine source in water, adding aqueous graphene oxide solution, mixing uniformly, performing hydrothermal reaction at 150-260 degrees C, obtaining lithium-iron phosphate anode material precursor and sintering the precursor in a protective atmosphere. The chelated phosphine source is chosen from risedronic acid, 2-hydroxyphosphonoacetic acid, pamidronic acid, alendronic acid, ibandronic acid, zoledronic acid, aminomethylphosphonic acid, 2-aminoethylphosphonic acid, N,N-bis(phosphonomethyl)glycine, polyaminopolyether methylene phosphonic acid, polyol phosphate, hexamethylenediamine tetra(methylene phosphonic)acid and bis-1,6-(hexamethylenetriaminepenta(methylene phosphonic acid)). An INDEPENDENT CLAIM is included for graphene film-coated lithium-iron phosphate anode material, which comprises lithium-iron phosphate particles as core, coated with a layer of graphene nanofilm. The core has particle size of 5-500 nm. The thickness of the graphene nanofilm is 1-30 nm.