A lithium secondary battery is provided with a positive electrode, a negative electrode (1), a separator interposed between the positive and negative electrodes, and an electrode assembly having the negative electrode (1), the positive electrode, and the separator. The negative electrode (1) has a negative electrode current collector (11) and negative electrode active material layers (12), (13) formed on respective surfaces of the negative electrode current collector (11). The negative electrode active material layers are composed of an alloy containing silicon, which intercalates and deintercalates lithium, and iron, which does not intercalate or deintercalate lithium. At least a portion of the electrode assembly has a curved portion in which the negative electrode active material layer (13) disposed inward relative to the negative electrode current collector contains a higher concentration of the iron than the negative electrode active material layer (12) disposed outward relative to the negative electrode current collector.