BINARY, TERNARY AND QUATERNARY LITHIUM PHOSPHATES, PROCESS FOR THEIR PREPARATION AND THEIR USE

摘要

The invention relates to binary, ternary and quaternary lithium phosphates of general formula Li(FexM1yM2z)PO4 wherein M1 represents at least one element of the group comprising Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Be, Mg, Ca, Sr, Ba, Al, Zr, and La; M2 represents at least one element of the group comprising Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Be, Mg, Ca, Sr, Ba, Al, Zr, and La; x=between 0.5 and 1, y=between 0 and 0.5, z=between 0 and 0.5, provided that x+y+z=1, or x=0, y=1 and z=0. The said lithium phosphates can be obtained according to a method whereby precursor compounds of elements Li, Fe, M1 and/or M2 are precipitated from aqueous solutions and the precipitation product is dried in an inert gas atmosphere or a reducing atmosphere at a temperature which is between room temperature and approximately 200° C. and tempered at a temperature of between 300° C. and 1000° C. The inventive lithium phosphates have a very high capacity when used as cathode material in lithium accumulators.