【摘要】 采用沉淀法和水热法,合成了不同形貌的磷酸铁前驱体,并用碳热还原法得到LiFePO4/C正极材料。探讨了磷酸铁前驱体形貌特征对合成的磷酸铁锂电化学性能的影响程度。用XRD和SEM对产物物相结构、表观形貌进行了表征和分析。结果表明,水热合成的时间越长,磷酸铁的结晶性越好,趋于球形,电化学性能越好;但反应温度达180℃时,形貌趋向于椭圆,放电比容量反而较高。不同形貌的磷酸铁制备出的磷酸铁锂均为橄榄石结构,物相均一;不同形貌磷酸铁制备的磷酸铁锂正极材料电化学性能各异。磷酸铁形貌对磷酸铁锂正极材料电化学性能有影响,但不是决定因素。更多还原

【Abstract】 The iron phosphate precursors were prepared by precipitation method and hydrothermal synthesis method,and then LiFePO 4/C was synthesized by carbothermal reduction method.The effect of morphology of iron phosphate on the electrochemical performance of lithium iron phosphate was investigated.The characterization on the structure and morphology was carried out by XRD and SEM.The results indicate that with the longer time of the hydrothermal reaction,the crystallinity of the iron phosphate was better,the particles of iron phosphate became spherical,and the LiFePO 4/C had better the electrochemical performance.However,when the synthesis temperature reached 180 ℃,the particles became ellipsoidal and the LiFePO 4/C had a high discharge capacity on the contrary.All of the Lithium iron phosphate prepared by the iron phosphate precursors were homogeneous phase with olivine structure, but the different morphology resulted to different electrochemical performance of the LiFePO 4/C.The morphology of iron phosphate precursor effected the electrochemical property of the LiFePO 4/C,but it’s not the key point factor.更多还原