POWDER FOR LITHIUM ION SECONDARY BATTERY NEGATIVE ELECTRODE MATERIAL, LITHIUM ION SECONDARY BATTERY NEGATIVE ELECTRODE, CAPACITOR NEGATIVE ELECTRODE, LITHIUM ION SECONDARY BATTERY, AND CAPACITOR

摘要

Disclosed is a powder for a negative electrode material which can be used for a lithium ion secondary battery having high discharge capacity and good cycle properties, and capable of application at a practical level. Specifically disclosed is a powder for a lithium ion secondary battery negative electrode material, which comprises a lower silicon oxide powder and an electrically conductive carbon coating film formed on the surface of the powder, and which is characterized in that the content of Si (that is contained in SiC) is 15.1 wt% or less, or that A3 is 15.1 or less (A3 = 15.1) (wherein A1 (wt%) represents the Si content as measured by an acid dissolution method; A2 (wt%) represents the Si content as measured by an alkali dissolution method; and A3 = A2-A1) and the specific resistance is 30000 Ocm or less. It is preferred that the lower silicon oxide powder fulfills the requirement represented by the formula: P2/P1 x-derived halo that appears at 2?=10°-30° and P2 represents the value of a strongest intensity peak of Si(111) that appears at 2? = 28.4 ± 0.3° as measured by XRD using CuKa beam). It is also preferred that the content of a tar component is 1 to 4000 ppm inclusive.