MANUFACTURING METHOD OF LITHIUM ION SECONDARY BATTERY AND THE LITHIUM ION SECONDARY BATTERY

To provide a manufacturing method of a lithium ion secondary battery, enabling suppression of formation of a NaBOB coated film, and to provide the lithium ion secondary battery.SOLUTION: A manufacturing method of a lithium ion secondary battery includes: a positive electrode plate manufacturing step of manufacturing a positive electrode plate having a positive electrode mixture layer 23 which includes a positive electrode active material 31, a lithium hydroxide 32, and a lithium acetate 34; a negative electrode plate manufacturing step of manufacturing a negative electrode plate having a negative electrode mixture layer 26 which includes a negative electrode active material 41 and a sodium salt 42; and a step of injecting a non-aqueous electrolyte EL including LiBOB into a case in which the positive electrode plate and the negative electrode plate are housed. When the mol number of the lithium hydroxide 32 added in the positive electrode plate manufacturing step is A, the mol number of the lithium acetate 34 formed in the positive electrode plate manufacturing step is B, and the mol number of the sodium salt 42 added in the negative electrode plate manufacturing step is C, each value of A, B, and C satisfies 0.04≤B/A≤0.06 and 1.9≤B/C, and the lithium acetate 34 has a high solubility with respect to the non-aqueous electrolyte EL than that of a sodium acetate 50.SELECTED DRAWING: Figure 6 【課題】ＮａＢＯＢ被膜の形成を抑制可能としたリチウムイオン二次電池の製造方法及びリチウムイオン二次電池を提供する。【解決手段】正極活物質３１と水酸化リチウム３２と酢酸リチウム３４とを含む正極合剤層２３を備える正極板を製造する正極板製造工程と、負極活物質４１とナトリウム塩４２とを含む負極合剤層２６を備える負極板を製造する負極板製造工程と、正極板と負極板とを収容したケースに、ＬｉＢＯＢを含む非水電解液ＥＬを注液する工程と、を含み、正極板製造工程において添加される水酸化リチウム３２のモル数をＡ、正極板製造工程において形成される酢酸リチウム３４のモル数をＢ、負極板製造工程において添加されるナトリウム塩４２のモル数をＣとすると、Ａ、Ｂ、及びＣの値が、０．０４≦Ｂ／Ａ≦０．０６かつ１．９≦Ｂ／Ｃを満たし、酢酸リチウム３４は、酢酸ナトリウム５０よりも非水電解液ＥＬに対する溶解度が高い。【選択図】図６