Negative electrode active material for secondary battery and secondary battery

摘要

(1) It contains flaky artificial graphite A and massive artificial graphite B, (2) 50 in the volume-based particle size distribution of flaky artificial graphite A with respect to 50% diameter D50 (B) in the volume-based particle size distribution of massive artificial graphite B The ratio D50 (A) / D50 (B) of the% diameter D50 (A) is more than 0.6 and less than 1.0, and (3) the surface roughness R of the flaky artificial graphite A is 2.8 or more and 5.1. (4) The surface roughness R of the massive artificial graphite B is 6.0 or more and 9.0 or less, and (5) the massive artificial graphite B with respect to the total mass of the flaky artificial graphite A and the massive artificial graphite B The negative electrode active material for secondary batteries whose mass ratio B / (A + B) is 0.03 or more and 0.30 or less.