LiFePO_4的Pechini法合成及电化学性能研究

Study on synthesis and electrochemical performance of LiFePO_4 by Pechini method

采用Pechini法制备前驱体并合成LiFePO4。对LiFePO4前驱体进行热重和示差扫描量热分析(TG-DSC),采用X射线衍射(XRD)对试样的微观结构进行表征,并对试样进行电化学性能测试。结果表明:600℃合成的试样具有适中的晶胞体积、晶粒尺寸及最佳的电化学性能。采用0.1C倍率充放电,第三循环放电容量为158.55mAh/g,平台比容量及平台率分别为144.94mAh/g、91.42%,在1C倍率下充放电,其放电比容量大于130mAh/g。

The precursor was prepared by Pechini method and LiFePO4 was synthesized at different temperatures. The precursor was analyzed by TG-DSC. The microstructure of the samples was characterized by XRD. The electrochemical experiments of the samples were carried out. The experimental results show that sample C possesses moderate cell volume, crystallite size and the most excellent electrochemical performance. Its third cyclic discharge capacity is 158.55 mAh/g, plateau capacity and plateau ratio are 144.94 mAh/g, 91.42%, respectively, when 0.1 C rate is applied, its discharge capacity reaches 130 mAh/g at 1 C rate.