| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery improved in capacity and cycle characteristics by use of a negative electrode active material including particles having a structure in which silicon microcrystalline is distributed in silicon dioxide.SOLUTION: A method for manufacturing a negative electrode active material comprises the step of mixing fine powder A and fine powder B so that in a particle size distribution measured by a particle size distribution measurement method by laser diffraction scattering, the cumulative 90%-particle size (D) is 50 μm or less, and the content of the fine powder B having a particle size of less than 2 μm is 1-30 mass%. In the method for manufacturing a negative electrode active material, the fine powder A consists of particles each having a structure in which silicon microcrystalline having a crystal size of 1-500 nm is distributed in silicon, dioxide, silicon oxide or a mixture thereof, and having a particle size of 2 μm or larger; and the fine powder B consists of particles each having a structure in which silicon microcrystalline having a crystal size of 1-500 nm is distributed in silicon dioxide, silicon, silicon oxide or a mixture thereof, and having a particle size of less than 2 μm. |
