▎ 摘　　要

NOVELTY - Nano-lithium iron phosphate composite spherical graphene electrode material comprises nano-lithium iron phosphate and spherical graphene, where the spherical graphene is coated on the surface of the nano-lithium iron phosphate, the size of the nano-lithium iron phosphate is 0.35-1.8 mu m, and the structure of the spherical graphene is a three dimensional porous network structure. USE - As nano-lithium iron phosphate composite spherical graphene electrode material. ADVANTAGE - The electrode material uses nano-lithium iron phosphate composite spherical graphene to improve the stability of the nano-lithium iron phosphate while increasing the conductivity, and uses spherical graphene which has higher mobility and excellent synergistic effect to improve the electron transmission efficiency. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a preparation method of the nano-lithium iron phosphate composite spherical graphene electrode material, involving (i) dissolving lithium hydroxide hydrate, phosphoric acid and ferrous sulfate heptahydrate in ethylene glycol, dripping resulting phosphoric acid solution into the lithium hydroxide hydrate solution tank under vigorous stirring, (ii) adding the ferrous sulfate solution to the suspension when step (i) produces a white suspension, stirring at room temperature for 30 minutes, transferring the mixture to a sealed autoclave and heated to 175 degrees C for 12 hours, cooling to room temperature, washing the gray-green precipitate with deionized water and ethanol and drying in a vacuum drying oven at 80 degrees C to obtain lithium iron phosphate (LFP), (iii) ultrasonically dispersing lithium iron phosphate nanosheets in ethanol, pouring aminopropyltrimethoxysilane (APS) into the above solution and refluxing for 12 hours to obtain positively charged aminopropyltrimethoxysilane modified nanoparticles lithium iron phosphate, (iv) collecting the precipitate and washing with deionized water several times, and adding deionized water to the obtained precipitate to prepare an aminopropyltrimethoxysilane-modified lithium iron phosphate nanoplate solution, which is called p-LFP, (v) adding grams of styrene monomer and polyvinylpyrrolidone (PVP) to deionized water, and stirring the mixture at room temperature under nitrogen protection for 30 minutes, (vi) adding the deionized aqueous solution containing 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA) to the mixture under stirring and nitrogen protection for 1 hour, collecting the final solid using a centrifuge and drying in an oven at 60 degrees C, increasing the reaction temperature to 70 degrees C, reacting under nitrogen protection for 24 hours to obtain positively charged polystyrene spheres (p-PS), (vii) washing the graphene oxide (GO) with a large amount of deionized water, storing in an aqueous solution, ultrasonically treating the graphene oxide solution for 30 minutes, adding positively charged lithium iron phosphate to a phosphate solution containing 400 mg p-LFP nanosheets and stirring at room temperature for 1 hours, and (viii) ultrasonically treating p-PS in deionized water for 10 minutes, dripping to the GO/p-LFP solution and stirring for another 24 hours at room temperature, washing, drying, and carbonizing to obtain the product GO/p-LFP(x), where the x is the quality of GO.