| abstract |
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 (Ni½ Mn½)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. |