A general solution-chemistry route to the synthesis LiMPO₄ (M=Mn, Fe, and Co) nanocrystals with [010] orientation for lithium ion batteries

A general and efficient solvothermal strategy has been developed for the preparation of lithium transition metal phosphate microstructures (LiMnPO ₄, LiFePO₄, and LiCoPO₄), employing ethanol as the solvent, LiI as the Li source, metal salts as the M sources, H ₃PO₄ as the phosphorus source, and poly(vinyl pyrrolidone) (PVP) as the carbon source and template. This route features low cost, environmental benign, and one-step process for the cathode material production of Li-ion batteries without any complicated experimental setups and sophisticated operations. The as-synthesized LiMPO₄ microstructures exhibit unique, well-shaped and favorable structures, which are self-assembled from microplates or microrods. The b axis is the preferred crystal growth orientation of the products, resulting in a shorter lithium ion diffusion path. The LiFePO₄ microstructures show an excellent cycling stability without capacity fading up to 50 cycles when they are used as a cathode material in lithium-ion batteries.