Low-Cost Method for Making Lithium Transition Metal Olivines with High Energy Density

摘要

An inexpensive method for making lithium transition metal olivine particles that have high specific capacities is disclosed. The method includes the steps of: a) combining precursor materials including at least one source of lithium ions, at least one source of transition metal ions, at least one source of HxP04 ions where x is 0-2 and at least one source of carbonate, hydrogen carbonate, formate and/or acetate ions in a mixture of water and a liquid cosolvent which is miscible with water at the relative proportions of water and cosolvent that are present and which liquid cosolvent has a boiling temperature of at least 130° C.; wherein the mole ratio of lithium ions to HxP04 ions is from 0.9:1 to 1.2:1, and a lithium transition metal phosphate and at least one of carbonic acid, formic acid or acetic acid are formed, b) heating the resulting mixture at a temperature of up to 120° C. to selectively remove the carbonic acid, formic acid, acetic acid and/or carbon-containing decomposition products thereof from the reaction mixture, optionally remove some or all of the water from the reaction mixture and produce lithium transition metal olivine particles, and then c) separating the lithium transition metal olivine particles from the liquid cosolvent.

主权项

1. A method for making lithium transition metal olivine particles, comprising the steps of:
a) a) combining precursor materials including at least one source of lithium ions, at least one source of transition metal ions which includes at least one source of Fe(II) ions and at least one source of Co(II) ions, Mn(II) ions or both Co(II) and Mn(II) ions, at least one source of HxPO4 ions where x is 0-2 and at least one source of carbonate, hydrogen carbonate, formate and/or acetate ions in a mixture of water and a liquid cosolvent which is miscible with water at the relative proportions of water and cosolvent that are present and which liquid cosolvent has a boiling temperature of at least 130° C.; wherein the mole ratio of lithium ions to HxPO4 ions is from 0.9:1 to 1.2:1, and a lithium transition metal phosphate and at least one of carbonic acid, formic acid or acetic acid are formed, b) heating the resulting mixture at a temperature of up to 120° C. to selectively remove the carbonic acid, formic acid, acetic acid and/or carbon-containing decomposition products thereof from the reaction mixture, optionally remove some or all of the water from the reaction mixture and produce lithium transition metal olivine particles, and then c) separating the lithium transition metal olivine particles from the liquid cosolvent.