Lithium secondary battery

A lithium secondary battery comprising,

• a positive electrode;
• and
• a negative electrode in which deposition and dissolution reactions of lithium metal occur, wherein:
• the negative electrode includes a negative electrode layer;
• the negative electrode layer contains, as a negative electrode active material, an alloy of the lithium metal and a dissimilar metal;
• an element percentage of lithium element in the alloy is 40.00 atomic % or more and 99.97 atomic % or less when the lithium secondary battery is fully charged,
• the negative electrode layer includes an oxygen-enriched portion in which oxygen is enriched,
• a sectional area of the oxygen-enriched portion is 1% or more and 60% or less when a sectional area of the negative electrode layer is taken as 100%, and
• the oxygen-enriched portion and the negative electrode layer are formed simultaneously by at least three crucibles, one containing the lithium metal, one containing the dissimilar metal, and one containing an oxygen-introducing compound, and the at least three crucibles are heated to simultaneously volatilize the lithium metal, the dissimilar metal, and the oxygen-introducing compound in a vacuum deposition apparatus and deposit the lithium metal, the dissimilar metal, and the oxygen-introducing compound.