To provide carbonaceous powder that prevents the decomposition of an electrolyte without adversely affecting an electrode reaction rate when used as a negative electrode active material or degrading the fluidic characteristics of electrode forming paste, and provides a nonaqueous secondary battery having small irreversible capacity.
In the case of this carbonaceous powder for a nonaqueous secondary battery, its micro-roughness value obtained from a particle shape analysis according to an image analysis method is 1×106 μm or less. The carbonaceous powder can be manufactured by finely crushing a carbonaceous material, and applying mechanical friction force to the obtained carbonaceous powder or heat-treating the obtained carbonaceous powder at a temperature above 400°C under an atmosphere having oxygen concentration of 500 ppm or less. By virtue of this manufacturing method, the carbonaceous powder for a nonaqueous secondary battery which has a small surface area and for which the fine roughness and fuzz of its surface is reduced can be provided even if the average particle size or particle size distribution range of the powder is not reduced.
TAKAO NORITOSHI
KAMATA TOMIYUKI
Next Patent: SECONDARY BATTERY