▎ 摘　　要

NOVELTY - Preparing graphene-modified-carbon-coated lithium iron phosphate material, involves dissolving phosphate raw material, iron salt and lithium source in an alcohol solution in a molar ratio of 1:3:(1-1.05) to obtain a first mixed solution, adjusting the pH value of the first mixed solution to 6.8-7.2 to obtain a second mixed solution. The templating agent, a carbon source and an antioxidant are added to the second mixed solution, stirred and dissolved to obtain a third mixed solution, where the templating agent, the carbon source and the antioxidant are account for 1-2 wt.%, 0.2-0.5 wt.% and 1-2 wt.% second mixed solution by mass respectively. The graphene oxide is added to the third mixed solution and carried out ultrasonic dispersion to obtain fourth mixed solution, where the mass percent of the graphene oxide in the third mixed solution is 0.5-1 wt.%. USE - Method for preparing graphene-modified-carbon-coated lithium iron phosphate material used in solid-state lithium-ion battery (claimed). ADVANTAGE - The G/LFP/C material is applied to a solid-state battery, which helps in transportation of electrons and lithium ions, and reduces the interface impedance, so that the solid-state battery made of the G/LFP/C material has excellent rate performance, electrochemical lithium storage performance and cycle performance. DETAILED DESCRIPTION - Preparing graphene-modified-carbon-coated lithium iron phosphate material, involves dissolving phosphate raw material, iron salt and lithium source in an alcohol solution in a molar ratio of 1:3:(1-1.05) to obtain a first mixed solution, adjusting the pH value of the first mixed solution to 6.8-7.2 to obtain a second mixed solution. The templating agent, a carbon source and an antioxidant are added to the second mixed solution, stirred and dissolved to obtain a third mixed solution, where the templating agent, the carbon source and the antioxidant are account for 1-2 wt.%, 0.2-0.5 wt.% and 1-2 wt.% second mixed solution by mass respectively. The graphene oxide is added to the third mixed solution and carried out ultrasonic dispersion to obtain fourth mixed solution, where the mass percent of the graphene oxide in the third mixed solution is 0.5-1 wt.%. The fourth mixed solution is poured into the reactor for hydrothermal synthesis to obtain solid phase material. The solid phase material is then placed in a vacuum oven for drying, and then placed in a muffle furnace for high-temperature calcination to obtain target product. INDEPENDENT CLAIMS are included for: A graphene modified-carbon coated lithium iron phosphate material is prepared by method. A solid-state lithium-ion battery, which comprises positive electrode material prepared from the graphene-modified-carbon-coated lithium iron phosphate material.