Negative electrode, solid lithium-ion battery, and method for manufacturing a negative electrode

Abstract

Providing a negative electrode capable of increasing the initial discharge capacity and reducing the variation in initial discharge capacity. [Solution] A 25 μm square region in a backscattered electron image at 5000x magnification of a cross-section of the negative electrode mixture layer is divided into X1 divisions, X2 divisions, ···, X n-1 divisions and X n divisions so that the areas are equal, and the average value SX of the area ratio [%] occupied by the region attributed to the silicon-based active material in the ternarized region 1,ave [%], SX 2,ave [%], ···, SX n-1,ave [%] and SX n,ave [%], as well as the average value SX of the area ratio [%] occupied by the region attributed to the solid electrolyte 1,ave '[%], SX 2,ave '[%], ···, SX n-1,ave '[%] and SX n,ave '[%] are determined, then the average value S[%] of SX 1,ave , SX 2,ave , ···, SX n-1,ave and SX n,ave , and the average value S'[%] of SX 1,ave ', SX 2,ave ', ···, SX n-1,ave ' and SX n,ave ' are determined, the formula 90≦S+S' is satisfied.

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