| 摘要 |
A non-aqueous electrolyte secondary battery having a positive electrode active material with excellent water resistance is provided. The non-aqueous electrolyte secondary battery includes a positive electrode containing positive electrode active material particles composed of a core section formed of olivine type LiFePO 4 ; an intermediate section that lies on the outer side of the core section and has a lithium iron phosphate that can be represented by the formula: LiFe x P y O z ; and a surface section that lies on the outer side of the intermediate section and has lithium iron phosphate that can be represented by the formula: LiFe a P b O c ; and a negative electrode containing lithium titanate, in which battery the molar concentration ratio of Fe relative to P of the lithium iron phosphate at the core section is greater than the average of the ratio x/y of LiFe x P y O z , the average value of the ratio a/b of LiFe a P b O c at the surface section of the positive electrode active material particles is smaller than the average of the ratio x/y of LiFe x P y O z , and the positive electrode active material particles include a region in which the ratio x/y of LiFe x P y O z at the intermediate section increases continuously or intermittently in the direction from the surface section toward the core section. |
