POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

To provide a positive electrode active material for a nonaqueous electrolyte secondary battery, capable of providing a nonaqueous electrolyte secondary battery having excellent output characteristics when being used for a nonaqueous electrolyte secondary battery.SOLUTION: There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery, including a lithium-nickel composite oxide particle. The lithium-nickel composite oxide particle includes a lithium-nickel composite oxide containing Li, Ni, Co and Al, and satisfying a substance ratio of each element of Li:Ni:Co:Al=a:1-x-y:x:y (where, 0.8≤a≤1.2, 0.03≤x≤0.20, 0.01≤y≤0.10). The lithium-nickel composite oxide particle is a secondary particle in which primary particles are aggregated. The (001) plane among the (001) plane, the (100) plane and the (110) plane accounts for 40% or more in a cross section of the secondary particle of the lithium-nickel composite oxide particle.SELECTED DRAWING: None 【課題】非水系電解質二次電池に用いた場合に、出力特性に優れた非水系電解質二次電池とすることができる非水系電解質二次電池用正極活物質を提供することを目的とする。【解決手段】リチウムニッケル複合酸化物粒子を含む非水系電解質二次電池用正極活物質であって、前記リチウムニッケル複合酸化物粒子は、Ｌｉと、Ｎｉと、Ｃｏと、Ａｌとを含み、各元素の物質量比がＬｉ：Ｎｉ：Ｃｏ：Ａｌ＝ａ：１−ｘ−ｙ：ｘ：ｙ（ただし、０．８≦ａ≦１．２、０．０３≦ｘ≦０．２０、０．０１≦ｙ≦０．１０）を満たすリチウムニッケル複合酸化物を含み、前記リチウムニッケル複合酸化物粒子は、一次粒子が凝集した二次粒子であり、前記リチウムニッケル複合酸化物粒子の前記二次粒子の断面において、（００１）面と、（１００）面と、（１１０）面とのうち、（００１）面が占める割合が４０％以上である非水系電解質二次電池用正極活物質を提供する。【選択図】なし