Process for making a coated cathode active material, and coated cathode active material

A process for making a coated cathode active material, wherein said process comprises the following steps:

• (a) providing an electrode active material according to general formula Li1+xTM1−xO2, wherein TM is a combination of metals according to formula (I), and x is in a range of from zero to 0.2, with a moisture content in a range of from 500 to 1,500 ppm,
• with
• a being in a range of from 0.3 to 0.4,
• b being in a range of from zero to 0.1,
• c being in a range of from 0.6 to 0.7, and
• d being in a range of from zero to 0.1,
• M is Al or Ti or Zr or Mg, and
• a
• +
• b
• +
• c
• =
• 1
• ,
• (b) reacting said electrode active material with a silicon alkoxide and an alkyl aluminum compound in one or more sub-steps, and
• (c) heat-treating the material obtained in step (b) in an oxygen-containing atmosphere at a temperature in a range of from 100 to 400° C. for 10 minutes to 4 hours.