METHOD FOR PREPARING LITHIUM IRON PHOSPATE NANOPOWDER COATED WITH CARBON

摘要

The present invention relates to a method for preparing a lithium iron phosphate nanopowder coated with carbon and a lithium iron phosphate nanopowder prepared by the same. The method comprises the steps of: (a) putting a lithium precursor, an iron precursor, and a phosphorus precursor into a reaction solvent to prepare a mixture solution; (b) introducing the mixed solution into a reactor and reacting the mixed solution to prepare an amorphous lithium iron phosphate nanoseed; and (c) heat treating the prepared lithium iron phosphate nanoseed to prepare a lithium iron phosphate nanopowder in which particle surfaces are partially or entirely coated with carbon. The particle size and grain distribution can be controlled by simple two-step processes to prepare a lithium iron phosphate nanopowder in which a carbon-coated layer is formed on particles thereof in a short time. Also, a lithium ion secondary battery including the prepared lithium iron phosphate nanopowder coated with carbon as a positive electrode active material has excellent capacity and stability.