NEGATIVE-ELECTRODE ACTIVE MATERIAL AND BATTERY

A negative electrode active material of the present disclosure includes composite particles 10 each including a base particle 11. The base particle 11 includes an alkali aluminate phase 12 including at least one alkali metal element and AI, and a silicon phase 13 dispersed in the alkali aluminate phase 12. The total pore volume of pores 14 having a diameter of 10 nm or more and 200 nm or less in the composite particles 10, as calculated by the BJH method, is 0.05 cm/g or less.