LITHIUM-ION SECONDARY BATTERY

An electrode body includes an overlapping part where a negative electrode sheet and a separator overlap each other in a thickness direction. The overlapping part includes an inside part located more inside than a peripheral part of the overlapping part when the overlapping part is seen in plan view in the thickness direction. The inside part satisfies the relationship, A>C and B>C, wherein A denotes interlayer separation strength between the separator and a negative electrode mixture layer, B denotes interlayer separation strength between the negative electrode mixture layer and a negative current collector foil, and C denotes intralayer separation strength of the negative electrode mixture layer.