Patent ID: 11916185
Assignee: A123 SYSTEMS LLC
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  C  Y | IPC C  H

Claim 0:
1. A method to form a lithium iron phosphate electrochemically active material for use in an electrode in an electrochemical energy storage device, comprising:
(a) mixing a trivalent vanadium dopant source, an optional cobalt co-dopant source, a lithium source, a carbon source, and an iron phosphate source comprised of at least an iron cation and a phosphate anion, and having an iron content of at least 28 wt. % and a molar ratio of the phosphate anion to the iron cation of 1.000:1-1.040:1, in a solvent to form a slurry, wherein the trivalent vanadium dopant source shares a common anion with the iron phosphate source;
(b) milling the slurry;
(c) drying the milled slurry to form a lithium iron phosphate precursor powder; and
(d) firing the dried milled slurry to obtain the lithium iron phosphate electrochemically active material, wherein the lithium iron phosphate electrochemically active material comprises a trivalent vanadium dopant and/or a cobalt co-dopant partially substituting the Fe in a crystal lattice structure, the trivalent vanadium dopant and the cobalt co-dopant formed, respectively, from the trivalent vanadium dopant source and the optional cobalt co-dopant source, a phosphate anion to iron molar ratio of 1.000:1-1.050:1, and a total non-lithium metal to phosphate anion molar ratio of 1.000:1-1.040:1.