NEGATIVE ELECTRODE ACTIVE MATERIAL AND BATTERY

A negative electrode active material of the present disclosure includes a base particle 10 including: an alkali aluminate phase 11 including at least one alkali metal element and Al; a silicon phase 12 dispersed in the alkali aluminate phase 11; and a carbon phase 13 dispersed in the alkali aluminate phase 11. An area ratio of the carbon phase 13 in a cross-section of a primary particle of the base particle 10 is 4% or more and 25% or less.