A composite reaction mechanism for the hydrothermal synthesis of olivine phosphates

Abstract LiMPO4 (M = Fe, Mn) is hydrothermally synthesized in the P-excess reaction system to elucidate the reaction mechanism, and the results unveil that the formation of LiMnPO4 and LiFePO4 has the same reaction mechanism of dissolution-precipitation-ion exchange. Such a composite mechanism contains a key step involving the precipitation of an intermediate during the hydrothermal reaction. This work provides a mechanistic insight into the hydrothermal synthesis of LiMPO4 in a P-excess reaction system, which is fundamentally important for optimal performance.