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

摘要

Provided is a negative-electrode material powder for a lithium-ion secondary battery including a conductive carbon film on the surface of a lower silicon oxide powder, in which the total content of tar components measured by TPD-MS is not less than 1 ppm by mass and not more than 4000 ppm by mass, and in the Raman spectrum, peaks exist at 1350 cm -1 and 1580 cm -1 , while the peak at 1580 cm -1 has a half-value width of not less than 50 cm -1 and not more than 100 cm -1 . In the negative-electrode material powder, a specific surface area measured by the BET method is preferably not less than 0.3 m 2 /g and not more than 40 m 2 /g, and the proportion of the conductive carbon film is preferably not less than 0.2 mass% and not more than 10 mass%. A specific resistance of the lower silicon oxide powder is preferably not more than 40000 ©cm, and a maximum value P1 of SiO x -incurred halos and a value P2 of the strongest line peak of Si (111) preferably satisfy a relationship of P2/P1<0.01 in XRD measurement. This makes it possible to provide a negative-electrode material powder which can be used to obtain a lithium-ion secondary battery as being durable at practical level with large discharge capacity and satisfactory cycle characteristics.