高级检索
无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

高温固相还原法合成LiFePO4/C正极材料及其电化学性能

谢辉1, 周震涛2   

  1. 1. 电子科技大学中山学院化学与生物系, 中山 528402; 2. 华南理工大学材料科学与工程学院, 广州 510640
  • 收稿日期:2006-08-07 修回日期:2006-10-09 出版日期:2007-07-20 网络出版日期:2007-07-20

Synthesis and Electrochemical Performances of LiFePO4/C Composites by Solid State Reduction Method

XIE Hui1, ZHOU Zhen-Tao2   

  1. 1. Electrochemical and Biologic Department, Zhong Shan College, University of Electronic Science and Technology of China, Zhongshan 528402, China; 2. College of Material Science & Engineering, South China University of Technology, Guangzhou 510640, China
  • Received:2006-08-07 Revised:2006-10-09 Published:2007-07-20 Online:2007-07-20

PDF (PC)

1913

摘要： 以Fe2O3为铁源, 用环氧树脂对反应前驱体进行包覆, 通过固相还原法制备了LiFePO4/C复合正极材料. 采用XRD、SEM、循环伏安以及充放电测试等方法对其晶体结构、表观形貌和电化学性能进行了研究. 研究结果表明, 煅烧温度对材料的电化学性能有较大影响, 在700℃煅烧所得产物为单一的橄榄石型晶体结构, 粒径分布较均匀, 且具有良好的电化学性能. 以0.1C倍率进行充放电, 其首次放电容量为150.3mAh/g, 充放电循环20周后, 容量保持率达99.2%; 以1.0、2.0C倍率进行充放电, 其首次放电容量分别为131.4和122.1mAh/g. 其在过充条件下的电性能也佳, 过充后还能继续放电, 但在过放电条件下, 其电性能迅速劣化.

关键词: 锂离子电池, 正极材料, 磷酸铁锂, 固相还原

Abstract: The LiFePO4/C composite cathode materials for lithiumion batteries were synthesized by a solid state reduction method. The crystalline structure, morphology of particles, and electrochemical performance of the sample were investigated by -ray diffraction, scanning electron microscope, charge-discharge test and cyclic voltammetry. The results show that the composite synthesized at 700℃ has a simple pure olivetype phase with small particles, and uniformly distribution of gain sizes, and shows the best electrochemical performances with 1st discharge specific capacity 150.3mAh/g and 20 th discharge specific capacity retention ratio 99.2% at 0.1C rate. It also shows good rate capability with 131.4mAh/g, 122.1mAh/g at the high rate of 1.0C and 2.0C, respectively. With the excellent characteristic to resist overcharge, this composite can retain its microstructure even after long time overcharge, but it is vulnerable to overdischarge.

Key words: lithium-ion batteries, lithium iron phosphate, solid state reduction

中图分类号: