NEGATIVE ELECTRODE ACTIVE MATERIAL, PROCESS OF MANUFACTURING THE SAME, AND POWER STORAGE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode active material having a small BET specific surface area and a reduced content of a SiOcomponent, and to provide a power storage device using the same for a negative electrode.SOLUTION: The negative electrode active material is manufactured by heat treating layered polysilane, having a structure in which a plurality of six-membered rings composed of silicon atoms are coupled, and represented by a composition formula (SiH), and is composed of a nano-silicon material whose BET specific surface area is 20 m/g or less, and contained oxygen amount is 30 mass% or less.