Synthesis and Characterization of LiFePO4 and LiTi0.01Fe0.99PO4 Cathode Materials

Authors

G. X. Wang, University of WollongongFollow
S. Bewlay, University of Wollongong
Scott A. Needham, University of WollongongFollow
Hua-Kun Liu, University of WollongongFollow
R. C. Liu, National Taiwan University, Taiwan
V. A. Drozd, National Taiwan University, Taiwan
J. F. Lee, National Synchrotron Radiation Centre, Taiwan
J. M. Chen, National Synchrotron Radiation Centre, Taiwan

RIS ID

15928

Publication Details

This article was originally published as Wang, GX, Bewlay, S, Needham, SA et al, Synthesis and Characterization of LiFePO4 and LiTi0.01Fe0.99PO4 Cathode Materials, Journal of the Electrochemical Society, 153(1), 2006, A25-A31. Copyright The Electrochemical Society. Original journal available here.

Abstract

Nanocrystalline LiFePO₄ and doped LiTi_0.01Fe_0.99PO₄ powders were synthesized via a sol-gel preparation route. High-resolution tunneling electron microscopy observation and energy dispersive spectroscopy, mapping show the homogeneous distribution of dopant Ti cations in the crystals. Fe and O K -edge X-ray absorption near-edge structure (XANES) measurements show that Ti⁴⁺ doping induces an increased unoccupied d-state in LiFePO₄, resulting in an enhanced p-type semiconductivity. In situ Fe K -edge XANES measurements of Ti-doped and undoped LiFePO₄ electrodes have been performed to determine the change of Fe valence during the lithium intercalation and de-intercalation processes. Both LiFePO₄ and doped LiTi_0.01Fe_0.99PO₄ cathodes demonstrate good electrochemical performance.