Solid state synthesis of LiFePO(4) studied by in situ high energy X-ray diffraction

The phase evolution and crystal structure transition of materials during solid-state synthesis of LiFePO4 were investigated by in situ high energy X-ray diffraction. It was found that the solid state reaction forming LiFePO4 started at a very low temperature, and LiFePO4 was clearly observed when the reaction temperature was above 173 degrees C. In situ X-ray diffraction data also revealed that several impurities appeared when the reaction temperature was above 400 degrees C. These impurities were successfully indexed with ex situ X-ray diffraction as Li3PO4, Fe2P, and Fe3P.Research at Argonne National Laboratory was funded by US Department of Energy, FreedomCAR and Vehicle Technologies Office. Argonne National Laboratory is operated for the US Department of Energy by UChicago Argonne, LLC, under contract DE-AC02-06CH11357. This work was also supported by the National Research Foundation of Korea Grant funded by the Korean Government (MEST) (NRF-2009-C1AAA001-0093307)