Nano-crystalline LiMnPO4 prepared by a new phosphate–formate precursor method

The preparation of homogeneous phosphate–formate precursors by freeze-drying of solutions containing lithium, Mn(II), phosphate and formate ions ensures production of stoichiometric, well crystallized, defectless and nano-sized LiMnPO4 powders at temperatures above 400 °C. A systematic study of the influence of the synthesis conditions on the structure and morphology of LiMnPO4 is performed. It is established that the concentration of the solutions subjected to freeze-drying and the annealing temperature strongly affect the structure, particle dimensions and morphology of LiMnPO4. LiMnPO4 with low extent of Li-to-Mn disorder (below 1%) are formed between 500 and 600 °C. Uniform and regular particles with close sizes distribution in the 60–120 nm range are prepared from diluted freeze-dried solutions and at relatively low annealing temperature.