We report on the suppression of FeLi• antisite defects in LiFe(PO 4)1-xF3x with 0 ≤ x ≤ 0.4 prepared by sol-gel and hydrothermal methods. Evidence for a systematic suppression of antisite defects upon fluorine doping in LiFePO4 is inferred from Fourier transform infrared spectra, wherein a noticeable red shift in the symmetric P-O stretching vibrational mode of (PO4) 3- polyanion from 970 to 957 cm-1 was observed. We report detailed structural and compositional studies of LiFe(PO4) 1-xF3x, and discuss the implications for the performance of LiFePO4 cathodes in lithium ion batteries.© 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.