| CPC H01M 4/525 (2013.01) [H01M 4/0471 (2013.01); H01M 4/505 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 14 Claims |

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1. A method for preparing a powderous positive electrode material comprising single crystal monolithic particles comprising Ni and Co and having a general formula Li1+a ((Niz (Ni1/2 Mn1/2)y Cox)1-k Ak)1-a O2, wherein A is a dopant, −0.03≤a≤0.06, 0.05≤x≤0.35, 0.10≤z≤0.95, x+y+z=1 and k≤0.05, the method comprising the steps of:
providing a mixture comprising a Ni- and Co- bearing precursor and a Li bearing precursor,
subjecting the mixture to a multiple step sintering process whereby in the final sintering step a sintered lithiated intermediate material is obtained comprising agglomerated primary particles having a primary particle size distribution with a D50 between 2.0 and 8.0 μm,
subjecting the lithiated intermediate material to a wet ball milling step whereby the agglomerated primary particles are deagglomerated and a slurry comprising deagglomerated primary particles is obtained,
separating the deagglomerated primary particles from the slurry, and
heat treating the deagglomerated primary particles at a temperature between 300° C. and at least 20° C. below the temperature in the final sintering step of the multiple step sintering process, whereby single crystal monolithic particles comprising Ni and Co are obtained.
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