Characterization of two lithiation reactions starting with an amorphous FePO sub(4 precursor)

LiFePO sub(4 was prepared using two synthetic routes which involved the precipitation and lithiation of an amorphous FePO) sub(4) precursor followed by a thermal treatment. Both hydrated and dehydrated FePO sub(4 were used. The XRD patterns confirm the amorphous nature of both the precipitated and the lithiated product, while a crystalline LiFePO) sub(4) product is obtained after thermal treatment. Moessbauer spectroscopy was used to analyse the oxidation state of iron during various stages of the reaction. The Moessbauer data demonstrates a large amount of Fe[super]3+ ions in the lithiated samples which suggest that the lithiation reaction does not go to completion. Therefore, the formation of LiFePO sub(4 may be in part associated with the thermal treatment and not the lithiation step.)