Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (08): 1504-1510.doi: 10.3866/PKU.WHXB20090728

• ARTICLE • Previous Articles     Next Articles

Electrochemical Performance of High-Density LiFePO4/C Composites Synthesized by Solid State-Carbothermal Reduction Method

ZHONG Mei-E, ZHOU Zhi-Hui, ZHOU Zhen-Tao   

  1. College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, P. R. China
  • Received:2009-01-12 Revised:2009-04-08 Published:2009-07-16
  • Contact: ZHOU Zhen-Tao E-mail:mcztzhou@scut.edu.cn

Abstract:

High-density LiFePO4/C composites were successfully synthesized by a solid state-carbothermal reduction method using Fe2O3 and citrate ferric as Fe3+ precursors in which the citrate acid radical acted as both reducing agent and carbon source. The reaction mechanism was investigated using thermogravimetric and differential scanning calorimetry (TG-DSC). The structures and physicochemical properties of the LiFePO4/C composites were characterized by X-ray diffraction, scanning electron microscopy, laser particle-size distribution measurement, tap-density testing and galvanostatic charge-discharge. Results indicated that the material calcined at 700 ℃ possessed a crystal olivine structure, a moderate particle size, excellent electrochemical performance and a high tap-density. It had a high initial discharge capacity of 129 mAh·g-1 at 17 mA·g-1 charge-discharge current density without decaying after twenty cycles. This material, which had a multi-peak particle size distribution, consisted of nanometer-sized and micrometer-sized particles and had high tap-density of 1.41 g·cm-3.

Key words: Li-ion battery, Cathode material, LiFePO4, Carbothermal reduction method, Citrate ferric

MSC2000: 

  • O646