CPC H01M 4/366 (2013.01) [C01G 53/50 (2013.01); H01M 4/0471 (2013.01); H01M 4/131 (2013.01); H01M 4/364 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 4/5815 (2013.01); H01M 10/0525 (2013.01); C01P 2002/01 (2013.01); C01P 2002/52 (2013.01); C01P 2002/54 (2013.01); C01P 2002/85 (2013.01); C01P 2004/03 (2013.01); C01P 2004/51 (2013.01); C01P 2004/61 (2013.01); C01P 2004/80 (2013.01); C01P 2006/40 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); H01M 2220/20 (2013.01)] | 15 Claims |
1. A positive electrode active material powder suitable for lithium-ion batteries, comprising lithium transition metal-based oxide particles, said particles comprising a core and a surface layer, said surface layer being on top of said core, said particles comprising the elements:
Li, M′ and oxygen, wherein M′ has a formula: M′=NizMnyCoxAk, wherein A is a dopant, 0.80≤z≤0.86, 0.05≤y≤0.20, 0.05≤x≤0.20, x+y+z+k=1, and k≤0.01,
said positive electrode active material powder having a median particle size D50 ranging from 5 μm to 15 μm and a surface layer thickness ranging from 10 nm to 200 nm,
said surface layer comprising:
sulfur in a content superior or equal to 0.150 wt % and inferior or equal to 0.375 wt % with respect to the total weight of the positive electrode active material powder,
sulfate ion (SO42−) in a content superior or equal to 4500 ppm and inferior or equal to 11250 ppm; and
aluminum and having an Al surface value A1/A2 that is superior or equal to 100, wherein A1 is an atomic ratio Al/(Ni+Mn+Co+Al+S) of the elements Al, Ni, Mn, Co, and S contained in the surface layer, said atomic ratio A1 being obtained by XPS spectrum analysis and wherein A2 is an atomic ratio Al/(Ni+Mn+Co+Al+S) obtained by ICP.
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