Synthesis of metal phosphates

Abstract

The present invention relates to a method for preparing a metal phosphate which comprises milling in a carbonaceous vessel a lithium source, a phosphate source, such as LiHPO, and a metal oxide containing a metal ion wherein the metal ion is capable of being reduced, to produced a milled mixture and heating the milled mixture in an inert atmosphere at a temperature and for a time sufficient to form a metal phosphate wherein the metal ion of the metal oxide is reduced in oxidation state without the direct addition of a reducing agent to the starting materials. In another embodiment the present invention relates to a method for preparing a mixed metal phosphate which comprises milling a lithium source and a phosphate source, such as LiHPO, a metal oxide and another metal compound wherein at least one of the metal compounds contains a metal ion capable of being reduced to produce a milled mixture and heating the resulting milled mixture in an inert atmosphere at a temperature and for a time sufficient to form a mixed metal phosphate, wherein the oxidation state of at least one of the metal ions is reduced in oxidation state without the direct addition of a reducing agent to the reactants. It is another object of the invention to provide electrochemically active materials produced by said methods.