| abstract |
[Problem] In a non-aqueous electrolyte secondary battery with a large capacity and a large area, even if a mixture of a high-capacity Si material and a carbon material with little swelling is used as the active material of the negative electrode, it is possible to achieve sufficient charge-discharge cycle characteristics. means. [Solution] A non-aqueous electrolyte secondary battery, characterized in that the ratio of the battery volume to the rated capacity is 10 cm 3 /Ah or less, and the rated capacity is 3 Ah or more, and has a power generating element comprising: : positive electrode, which is formed by forming a positive electrode active material layer containing a positive electrode active material on the surface of the positive electrode current collector; negative electrode, which is formed by forming a negative electrode active material layer containing a negative electrode active material on the surface of the negative electrode current collector and separator, the aforementioned negative electrode active material layer contains formula (1)=α (Si material) + β (carbon material) (wherein, the Si material is SiO selected from a mixture of amorphous SiO particles and Si particles (x represents the oxygen number for satisfying the atomic valence of Si) and one or more of the group consisting of Si-containing alloys, and the carbon material is selected from the group consisting of graphite, hardly graphitizable carbon, and amorphous carbon. One or more kinds, α and β represent the mass % of each component in the negative electrode active material layer, 80≤α+β≤98, 0.1≤α≤40, 58≤β≤97.9.) When selecting a plurality of arbitrary positions in the negative electrode active material layer, the difference between the maximum value and the minimum value of the area ratio (%) occupied by the binder in the visual field area of each image of the cross section of the negative electrode active material layer is within 10% . |