▎ 摘　　要

NOVELTY - Preparation of high-performance lithium iron phosphate/three-dimensional (3D) graphene composite involves preparing 1-10 mg/ml graphite oxide suspension; respectively dissolving 0.001-0.1 mol iron source and 0.001-0.1 mol phosphate in 30-50 ml deionized water; uniformly mixing solutions and adjusting pH to 0.5 with 0.5-5 mol/l aqueous ammonia; stirring for 0.5-5 hours; reacting reaction solution in 50-100 ml reactor with PTFE lining at 140 degrees C for 8 hours; cooling at room temperature; filtering; washing filter cake with deionized water and anhydrous ethanol for 3-5 times; drying at 80-100 degrees C for 24-48 hours to obtain pale green powder; adding 1 g pale green powder in 10-100 ml graphite oxide suspension; stirring for 1 hour; adding 0.02-0.2 g nickel chloride hexahydrate and subjecting to ultrasonic treatment for 2 hours; autoclaving at 180 degrees C for 12 hours; cooling, rinsing with deionized water and absolute ethanol, and freeze-drying. USE - Preparation of high-performance lithium iron phosphate/three-dimensional graphene composite used for power source. ADVANTAGE - The method has good safety, low cost, environmental friendly, and provides high-performance lithium iron phosphate/three-dimensional graphene composite with excellent electrochemical performance. DETAILED DESCRIPTION - Preparation of high-performance lithium iron phosphate/three-dimensional (3D) graphene composite comprises putting graphite oxide into dialysis bag; dialyzing in deionized water while replacing water for 3-5 times per day until pH is neutral; taking out graphite oxide gel and freeze-drying for 5-7 days to obtain solid graphite oxide; adding water to obtain graphite oxide suspension with concentration of 1-10 mg/ml; respectively dissolving 0.001-0.1 mol iron source and 0.001-0.1 mol phosphate in 30-50 ml deionized water; uniformly mixing solutions and adjusting pH to 0.5 with 0.5-5 mol/l aqueous ammonia; stirring for 0.5-5 hours; putting reaction solution in 50-100 ml reactor with PTFE lining; keeping reaction at 140 degrees C for 8 hours; cooling at room temperature; filtering; washing filter cake with deionized water and anhydrous ethanol for 3-5 times; drying at 80-100 degrees C for 24-48 hours to obtain pale green powder; adding 1 g pale green powder in graphite oxide suspension at concentration of 1-10 mg/ml; stirring at room temperature for 1 hour; adding 0.02-0.2 g nickel chloride hexahydrate and subjecting to ultrasonic treatment for 2 hours; placing in 50-100 ml PTFE-lined stainless steel autoclave; maintaining temperature at 180 degrees C for 12 hours; cooling at room temperature; taking out from autoclave and washing with deionized water and absolute ethanol for 3-5 times; freezing for 24-48 hours; freeze-drying for 48-96 hours; putting in tube furnace with argon gas; heating at 5-10 degrees C/minute to 550-750 degrees C and calcining for 2-10 hours to obtain black powder; taking 0.1-1.0 g black powder, 1-5 mmol lithium source and 0.1-1 mmol carbon source; adding 10 ml absolute ethanol; grinding to powder; putting in tube furnace filled argon gas; heating at 5-10 degrees C/minute to 350-550 degrees C for 5-10 hours; cooling at room temperature; adding mixture with 0.1-1.0 mmol carbon source; and calcining by heating at 5-10 degrees C/minute to 450-750 degrees C for 10-15 hours in tube furnace under protection of argon gas to obtain lithium iron phosphate/three-dimensional graphene composite material. The lithium source comprises lithium acetate, lithium carbonate and/or lithium hydroxide. The iron source comprises ferric chloride, ferric nitrate and/or ferrous sulfate. The phosphate comprises ammonium phosphate, ammonium dihydrogen phosphate, and/or ammonium hydrogen phosphate. The carbon source comprises ascorbic acid, glucose, and/or sucrose.