| 摘要 |
Disclosed is a powder for negative electrode materials for lithium ion secondary batteries, which has a conductive carbon coating film on the surface of each lower silicon oxide particle, and wherein the particle size distribution of the silicon oxide particles satisfies 1 µm = D50 = 20 µm, with D50 and D10 satisfying 1.4 = D50/D10 = 2.4. It is preferable that: the thickness of the conductive carbon coating film is 1.5-7.5 nm (inclusive); the specific surface area as determined by a BET method is 0.3-7.0 m2/g (inclusive); and the ratio of the conductive coating film is 0.5-10% by mass (inclusive). It is also preferable that: the total content of tar components as determined by TPD-MS is 1-4,000 ppm by mass (inclusive); and the maximum value (P1) of an SiOx-derived halo and the strongest line peak value (P2) of Si(111) as determined by XRD satisfy P2/P1 < 0.01. Consequently, a powder for negative electrode materials to be used in lithium ion secondary batteries, which has high discharge capacity and good cycle characteristics and is capable of withstanding practical use, can be obtained. |
