| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery, using a negative electrode active material containing silicon and oxygen, having long charge and discharge cycle life and high initial charge and discharge efficiency.SOLUTION: The lithium secondary battery includes the negative electrode, a positive electrode, and electrolyte. The negative electrode includes a negative electrode current collector and an negative electrode active material layer. The negative electrode active material layer is formed on the negative electrode current collector. The negative electrode active material layer contains silicon and oxygen. A low oxygen-content layer which includes less oxygen than the others part of the negative electrode active material layer is provided in a part of the negative electrode active material layer on the negative electrode current collector side. A thickness of the low oxygen-content layer is 25% or less of a thickness of the negative electrode active material layer. |
