NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, NEGATIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, NEGATIVE ELECTRODE FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND BATTERY PACK

摘要

PROBLEM TO BE SOLVED: To provide a long-life negative electrode active material for a nonaqueous electrolyte secondary battery.SOLUTION: A negative electrode material for a nonaqueous electrolyte secondary battery of an embodiment is a silicon oxide represented by a composition formula: SiO, including silicon and oxidized silicon, where 0.1≤x≤0.8 is satisfied. The silicon oxide contains crystal silicon, the number of granules having a diameter of 100 nm or less is 90% or more among the crystal silicon having a diameter of 1 nm or more, and a BET specific surface area of the silicon oxide is larger than 100 m/g.