Methods of manufacture and use of phosphates of transition metals are
described as positive electrodes for secondary lithium batteries,
including a process for the production of LiMPO.sub.4 with controlled
size and morphology, M being Fe.sub.xCo.sub.yNi.sub.zMn.sub.w, where
0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.w.ltoreq.1, and
x+y+z+w=1. According to an exemplary embodiment, a process is described
for the manufacture of LiFePO.sub.4 including the steps of providing an
equimolar aqueous solution of Li.sup.1+, Fe.sup.3+ and PO.sub.4.sup.3-,
evaporating water from the solution to produce a solid mixture,
decomposing the solid mixture at a temperature of below 500.degree. C. to
form a pure homogeneous Li and Fe phosphate precursor, and annealing the
precursor at a temperature of less than 800.degree. C. in a reducing
atmosphere to produce the LiFePO.sub.4 powder. The obtained powders can
have a particle size of less than 1 .mu.m, and can provide superior
electrochemical performance when mixed for an appropriate time with an
electrically conductive powder.