An electrode active material layer satisfies relations represented by an expression (1) “2.2≤X0≤15.0” and an expression (2) “|(X5−X1)/X1|≤25%”. X0 represents a ratio of a mass concentration of a first component (Ni, Co, Mn, Al, Fe, Ti, Si) to a mass concentration of a second component (S, P) in a cross section of the electrode active material layer. X1 represents a ratio of a mass concentration of the first component to a mass concentration of the second component in a region of the cross section closest to the electrode current collector; and X5 represents a ratio of a mass concentration of the first component to a mass concentration of the second component in a region of the cross section farthest from the electrode current collector.