Patent ID: 9325005
Filing Date: 2016-04-26
CPC Classification: C01G,C01P,H01M,Y02E,Y02P

Claim Text:
1. A method for producing a lithium nickel composite oxide for a positive electrode active material, represented by the following formula (1): wherein M represents a minor component of at least one element selected from the group consisting of a transition metal element other than Ni, a second group element and a thirteenth group element; a satisfies 0.01≦a≦0.5; and b satisfies 0.9≦b≦1.1, comprising the following steps (a) to (c): (a) preparing a nickel compound selected from a nickel hydroxide, a nickel oxyhydroxide or a nickel oxide, by (b) mixing the nickel compound and a lithium compound so that the amount of lithium in the lithium compound becomes 1.00 to 1.15 in molar ratio, relative to the total amount of nickel and the minor component in the nickel compound, and then firing the mixture under oxygen atmosphere in a range of a maximum temperature of 650 to 850° C.; (c) drying in two stages, in obtaining the lithium nickel composite oxide by filtering and drying, after water washing the fired substance obtained in the step (b), where a first stage drying is performed at equal to or lower than 90° C., until moisture content measured at a vaporization temperature of 300° C. in the lithium nickel composite oxide is reduced to equal to or lower that 1% by mass, and wherein a second stage drying is performed at equal to or higher than 120° C.; wherein, in the step (c), the first stage drying and the second stage drying are performed under vacuum atmosphere.