LMFP cathode materials with improved electrochemical performance

A method for making an olivine lithium manganese transition metal phosphate cathode material, comprising

• a) forming a mixture of at least one lithium precursor, at least one iron precursor, at least one manganese precursor, at least one dopant metal precursor selected from a magnesium precursor, a cobalt precursor or a mixture of magnesium and cobalt precursors and at least one precursor of HxPO4 ions where x is 0, 1 or 2, wherein the precursors are present in amounts such that:
• the mole ratio of lithium ions to HxPO4 ions is 1.04 to 1.08;
• the mole ratio of manganese ions to HxPO4 ions is 0.73 to 0.79;
• the mole ratio of iron ions to HxPO4 ions is 0.15 to 0.24;
• the mole ratio of dopant metal ions to HxPO4 ions is 0.003 to 0.053;
• and
• the mole ratio of lithium, manganese, iron and dopant metal ions combined to HxPO4 ions is such that (2.96×Moles HxPO4)≤[moles Li+(2×Moles Mn)+(2×Moles Fe)+(2×Moles Dopant Metal)]≤(3.086×Moles HxPO4) and (1.92×Moles HxPO4)≤[(2×Moles Mn)+(2×Moles Fe)+(2×Moles Dopant Metal)]≤(2.006×Moles HxPO4);
• b) milling the mixture and then;
• c) calcining the milled mixture to form the olivine lithium manganese iron phosphate cathode material.