| 摘要 |
Disclosed is a nonaqueous secondary battery that has a sufficiently small charge-discharge irreversible capacity at the time of the initial cycle, has excellent charging acceptance, and has an excellent cycle characteristic, even when the density of the active substance layer having negative electrode material on the collector is increased in order to increase the capacity. The composite graphite particle for a nonaqueous secondary battery, wherein a composite graphite particle (B) for which a spherical graphite particle (A) and a graphitized compound of a binder capable of graphitization have been combined, with said spherical graphite particle using a prescribed substance or said composite graphite particle fulfilling (a) and/or (b): (a) When the cumulative 50% diameter (d50 diameter), 90% diameter (d90 diameter), and 10% diameter (d10 diameter) of (A) by means of laser diffraction analysis are D50(A), D90(A), and D10(A), respectively, and when the cumulative 50% diameter (d50 diameter), 90% diameter (d90 diameter), and 10% diameter (d10 diameter) of (B) by means of laser diffraction analysis are D50(B), D90(B), and D10(B), respectively, Equation 1, Equation 2 and Equation 3 are fulfilled: 1.1=D50(B)/D50(A)=2.0 (1) 1.1=D90(B)/D90(A)=2.4 (2) 1.0=D10(B)/D10(A)=1.8 (3) (b) When the value of 110(A)/004(A), which is the ratio of the 110 plane to the 004 plane for (A) as measured by XRD, is x, and the value of 110(B)/004(B), which is the ratio of the 110 plane to the 004 plane for (B) as measured by XRD, is y, the ratio z thereof is defined by the formula z = y/x, with z being between 1.2 and 3.5. |
