Pure lithium hexafluorophosphate (LiPF6) was successfully prepared at room temperature (23 degrees C) by introducing fluorine gas into a reactor containing LiF and P at -196 degrees C. The mass fractions of LiPF6 and LiF in products prepared at 23 degrees C were 1.00 and 0.00, respectively, by means of XRD-Rietveld analysis. Namely, the prepared LiPF6 was pure enough to be used as an electrolyte salt in lithium ion batteries.