| CPC H01M 4/583 (2013.01) [H01M 4/0404 (2013.01); H01M 4/0471 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01)] | 12 Claims |

|
1. A negative electrode material for a lithium ion secondary battery, the negative electrode material comprising composite particles, each of the composite particles comprising: a spherical graphite particle; and flat graphite particles that are gathered or bound together such that the flat graphite particles have non-parallel orientation planes, wherein the composite particles satisfy the following conditions (1) and (2):
(1) a pore volume in a range of a pore diameter of from 0.10 to 8.00 μm obtained by a mercury intrusion method is from 0.20 to 1.00 mL/g; and
(2) in a log differential pore volume distribution obtained by the mercury intrusion method, wherein a peak is defined as a point at which a slope the log differential pore volume distribution changes from a positive value to a negative value, at least two peaks appear in a range of a pore diameter of from 0.10 to 8.00 μm, the at least two peaks including a first peak P1 and a second peak P2 at a higher diameter than the first peak P1, wherein:
a pore diameter corresponding to a maximum log differential pore volume of the first peak P1 is from 0.10 to less than 4.00 μm, and
a pore diameter corresponding to a maximum log differential pore volume of the second peak P2 is from 4.50 to 7.00 μm.
|