Nickel lithium metal composite oxide production method, nickel lithium metal composite oxide obtained by production method, and cathode active material including same

[Problem] To achieve high performance and reduce the costs of lithium ion battery cathode active materials. [Solution] A method for producing a nickel lithium metal composite oxide including steps 1 to 7. (Step 1) Melting process. (Step 2) Depositing process. (Step 3) Filtering process. (Step 4) Drying process. (Step 5) Mixing process of mixing aluminum hydroxide and lithium carbonate in a precursor powder obtained in step 4. (Step 6) High-temperature firing process of firing the mixture obtained in step 5 at a temperature higher than 790 DEG C. (Step 7) Low-temperature firing process of firing the fired article which has undergone step 6 at a temperature lower than 790 DEG C. 锂离子电池正极活性物质的高性能化和低成本化。包括以下工序1～7的镍锂金属复合氧化物的制造方法。(工序1)溶解工序。(工序2)沉淀工序。(工序3)过滤工序。(工序4)干燥工序。(工序5)混合工序，对工序4中所得到的前体粉末混合氢氧化铝和碳酸锂。(工序6)高温烧成工序，以高于790℃的温度对工序5中所得到的混合物进行烧成。(工序7)低温烧成工序，以低于790℃的温度对经工序6得到的烧成物进行烧成。