| abstract |
A negative electrode active material includes a carbon material, and at least one sulfur component selected from the group consisting of sulfur atoms and a sulfur compound, wherein a content of the sulfur component with respect to a total amount of the carbon material and the sulfur component is 0.0005 mass % or more and 0.01 mass % or less in terms of S measured by a fluorescent X-ray analysis method, the carbon material is artificial graphite, and the artificial graphite has a bulk density of 0.2 g/cm 3 or more and 2.5 g/cm 3 or less. A negative electrode includes a negative electrode current collector, and a negative electrode active material layer formed on the negative electrode current collector, wherein the negative electrode active material layer includes the above-described negative electrode active material. A lithium ion secondary battery includes the above-described negative electrode, a positive electrode, and an electrolytic solution. |