| abstract |
A nickel-based metal oxide for a lithium secondary battery, a nickel-based active material obtained from the nickel-based lithium metal oxide, a method of preparing the nickel-based metal oxide, and a lithium secondary battery including the nickel-based metal oxide as a cathode are provided. The nickel-based metal oxide for a lithium secondary battery is a single-crystal particle and includes a cubic composite phase, wherein the cubic composite phase includes a metal oxide phase represented by Formula 1 and a metal oxide phase represented by Formula 2: n Ni 1-x-z-k M k Li x Co z O 1-y , Formula 1n n wherein, in Formula 1, 0≤x≤0.1, 0≤y≤0.1, 0≤z≤0.5, and 0≤k≤0.5, n Ni 6-x-z-k M k Li x Co z MnO 8-y , and Formula 2n n wherein, in Formula 2, 0≤x≤0.1, 0≤y≤0.1, 0≤z≤0.5, and 0≤k≤0.5, and the case where x of Formula 1 and x of Formula 2 are 0 at the same time is excluded. |