Effect of Doping Ions on Electrochemical Properties of LiFePO4 Cathode
Lithium iron phosphate (LiFePO4) cathode materials containing different low concentration ion dopants (Mg2+, Al3+, Zr4+, and Nb5+) were prepared by a solid-state reaction method in an inert atmosphere. The effects of the doping ions on the properties of as-synthesized cathode materials were investigated. XRD results indicate that the ion dopants do not affect the structure of the materials. The galvanostatically charge and discharge tests show that ion dopants can considerably improve the electrochemical performance of the materials, especially large current discharge behaviors. LiFePO4 samples doped with Nb5+ have an initiate capacity of 146.8 mAh•g-1 at 0.1C. Further cycle performance measurements reveal the sample doped with Nb5+ shows the best cycleability. The results also verify that LiFePO4 doped with ions of suited radius and higher valence shows better electrochemical characters.
Huaiying Zhou, Tianlong Gu, Daoguo Yang, Zhengyi Jiang, Jianmin Zeng
Y. L. Ruan "Effect of Doping Ions on Electrochemical Properties of LiFePO4 Cathode", Advanced Materials Research, Vols. 197-198, pp. 1135-1138, 2011