NICKEL-BASED LITHIUM METAL COMPOSITE OXIDE, MANUFACTURING METHOD THEREOF, AND LITHIUM SECONDARY BATTERY HAVING POSITIVE ELECTRODE CONTAINING THE NICKEL-BASED LITHIUM METAL COMPOSITE OXIDE

To provide a nickel-based lithium metal composite oxide and a manufacturing method thereof, and a lithium secondary battery having a positive electrode that contains the nickel-based lithium metal composite oxide.SOLUTION: A nickel-based lithium metal composite oxide, a manufacturing method thereof, and a lithium secondary battery having a positive electrode containing the nickel-based lithium metal composite oxide are disclosed. The nickel-based lithium metal composite oxide comprises primary particles, and secondary particles including aggregates of the primary particles. In the nickel-based lithium metal composite oxide, a nickel content is 50 mol% or more to a transition metal total content. The secondary particles include large secondary particles of 10 μm or more in particle size, and small secondary particles of 5 μm or less in particle size. The large secondary particles are larger than the small secondary particles in nickel content.SELECTED DRAWING: Figure 1 【課題】ニッケル系リチウム金属複合酸化物、その製造方法、及びそれを含む正極を含むリチウム二次電池を提供する。【解決手段】一次粒子の凝集体を含む二次粒子を含み、ニッケルの含量が、ニッケル系リチウム金属複合酸化物において、遷移金属総含量を基準にし、５０モル％以上であるニッケル系リチウム金属複合酸化物であり、該二次粒子は、粒子サイズが１０μｍ以上である大粒二次粒子と、粒子サイズが５μｍ以下である小粒二次粒子と、を含み、該大粒二次粒子のニッケルの含量が、該小粒二次粒子のニッケルの含量に比べて多いニッケル系リチウム金属複合酸化物、その製造方法、及びそれを含む正極を含むリチウム二次電池である。【選択図】図１