Cathode active material and method for making such cathode active material

A cathode active material in particulate form with a mean particle diameter ranging from 2 µm to 16 µm (D50), wherein the cathode active material has 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),

• wherein:
• a ranges from 0.20 to 0.40,
• b ranges from zero to 0.15,
• c ranges from 0.50 to 0.75,
• d ranges from zero to 0.015, and
• e ranges of from zero to 0.02,
• M1 is selected from Al, Ti, Zr, Mo, Fe, Nb, and Mg,
• M2 is selected from B and K,
• with a + b + c = 1.0
• wherein the composite oxide has a specific surface (BET) ranging from 0.5 m2/g to 10 m2/g and a pressed density of at least 2.9 g/cm3, and
• wherein the cathode active material has an average primary particle diameter in the range of from 200 nm to 3,000 nm.

A process for making a cathode active material for lithium ion batteries wherein the process comprises:

• (a1) mixing a manganese composite (oxy)hydroxide whose metal part has a general formula (II a)
• with a source of lithium and a flux agent based on M
• 2, or
• (a2) mixing a manganese composite (oxy)hydroxide whose metal part has a general formula (II b)
• with a source of lithium and at least one compound of M1 and a flux agent based on M2, and
• (b) calcining the mixture at a temperature ranging from 800° C. to 1050° C., wherein
• a ranges from 0.20 to 0.40,
• b ranges from zero to 0.15,
• c ranges from 0.50 to 0.75,
• d ranges from zero to 0.015, and
• e ranges from zero to 0.02,
• wherein M1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, and
• M2 is selected from B, and
• with a + b + c = 1.0.