| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery having a low interface resistance between a positive electrode active material layer and a solid electrolyte layer and between a negative electrode active material layer and the solid electrolyte layer.SOLUTION: A lithium ion secondary battery of the present invention includes a solid electrolyte layer between a positive electrode layer and a negative electrode layer. The positive electrode layer includes a positive electrode current collector layer and a positive electrode active material layer. The negative electrode layer includes a negative electrode current collector layer and a negative electrode active material layer. The solid electrolyte layer is located between the positive electrode active material layer and the negative electrode active material layer. A ratio ((a particle diameter of the solid electrolyte)/(a particle diameter of a positive electrode active material or a negative electrode active material)) of a particle diameter of a solid electrolyte constituting the solid electrolyte layer with respect to one of particle diameters of a positive electrode active material and a negative electrode active material constituting the positive electrode active material layer and the negative electrode active material layer is in the range of 3.0 to 10.0. |
