| CPC H01M 4/525 (2013.01) [C01G 53/50 (2013.01); H01M 4/0471 (2013.01); H01M 4/505 (2013.01); H01M 10/0525 (2013.01); C01P 2006/40 (2013.01); H01M 2004/028 (2013.01)] | 12 Claims |
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1. A process for preparing a positive electrode material for lithium-ion batteries comprising the steps of:
subjecting a mixed metal compound pM comprising nickel and at least one metal selected from cobalt, manganese and aluminium to a heat treatment at a temperature TS of at least 650° C., thereby obtaining a heat-treated mixed metal compound M;
in a first cooling stage, cooling said heat-treated mixed metal compound M, at mean cooling rate, to an intermediate temperature TI being the lower of 700° C. and the sintering temperature TS;
in a second cooling stage, cooling said heat-treated mixed metal compound M from said intermediate temperature TI to 550° C. at a mean cooling rate of more than 2° C./min and of less than 10° C./min, wherein the mean cooling rate of the first cooling stage is more than the mean cooling rate of the second cooling stage; and
in a final cooling stage, cooling said heat-treated mixed metal compound M, at a mean cooling rate of at least 70° C./min, to ambient temperature, thereby obtaining a positive electrode material for lithium-ion batteries.
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