Process for making manganese-rich cathode active materials

A process for making a mixed oxide according to the formula Li1+xTM1−xO2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I)

• (NiaCobMnc)1-dM1d (I)
• wherein
• a ranges from 0.30 to 0.38,
• b ranges from zero to 0.05,
• c ranges from 0.60 to 0.70, and
• d ranges from zero to 0.05,
• M1 is selected from Al, Ti, Zr, W, Mo, Nb, Ta, Mg and combinations of at least two of the foregoing,
• a+b+c=1,
• wherein the process comprises:
• (a) providing a particulate hydroxide, oxide or oxyhydroxide of manganese, nickel, and, optionally, at least one of Co and M1,
• (b) adding a source of lithium to form a mixture,
• (c) calcining the mixture obtained from step (b) under an atmosphere comprising of from 0.05 vol.-% to 5 vol.-% of oxygen at a maximum temperature ranging from 650° C. to 1000° C.

A particulate material of a composition Li1+xTM1−xO2 wherein x ranges from 0.1 to 0.2 and TM is a combination of elements according to general formula (I)

• (NiaCobMnc)1-dM1d (I)
• wherein
• a ranges from 0.30 to 0.38,
• b ranges from zero to 0.05,
• c ranges from 0.60 to 0.70, and
• d ranges from zero to 0.0,
• M1 is selected from Al, Ti, Zr, W, Mo, Mg, Nb, Ta, and combinations of at least two of the foregoing,
• a+b+c=1,
• wherein the particulate material has an average particle diameter D50 ranging from 2 μm to 20 μm, a specific surface (BET) ranging from 0.7 m2/g to 3.8 m2/g,
• and wherein the particulate material has a pressed density ranging from 2.75 to 3.1 g/cm3.