Preparation and characterization of Na-doped LiFePO4/C composites as cathode materials for lithium-ion batteries

✍ Scribed by Xiongge Yin; Kelong Huang; Suqin Liu; Haiyan Wang; Hao Wang

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 817 KB
• Volume: 195
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2010.01.019

✦ Synopsis

To improve the performance of LiFePO 4 , single phase Li 1-x Na x FePO 4 /C (x = 0, 0.01, 0.03, 0.05) samples are synthesized by in situ polymerization restriction-carbonthermal reduction method. The effects of Na doping are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

The results indicate that doped Na ion does not destroy the lattice structure of LiFePO 4 , while enlarges the lattice volume. Electrochemical test results show that the Li 0.97 Na 0.03 FePO 4 /C sample exhibits the best electrochemical performance with initial special discharge capacity of 158 mAh g -1 at 0.1 C. EIS results demonstrate that the charge transfer resistance of the sample decreases greatly by doping an appropriate amount of Na.