NON-AQUEOUS SECONDARY BATTERY-USE GRAPHITE COMPOSITE PARTICLE, CATHODE ACTIVE SUBSTANCE MATERIAL CONTAINING IT, CATHODE AND NON-AQUEOUS SECONDARY BATTERY

摘要

To provide a nonaqueous secondary battery ensuring that a charge-discharge irreversible capacity at an initial cycle is sufficiently small even when an active material layer comprising a negative electrode active material on a current collector is increased in a density for obtaining a high capacity. This object is attained by a graphite composite particle for a nonaqueous secondary battery, which satisfies the requirements (1) and (2):
(1) D L /D S is more than 1 and 2 or less, wherein D L µm means a volume-based median size measured by a laser diffraction/scattering-type particle size distribution measuring apparatus, and D s µm means an average circle-equivalent particle size which is determined from a measured area S of particles each having a contour not overlapped with a contour of another particle in a SEM; and
(2) a Raman R value is 0.04 or more and 0.14 or less, wherein the Raman R value means an intensity ratio I B /I A between an intensity I A of a maximum peak of 1580 cm -1 around and an intensity I B of a maximum peak of 1360 cm -1 around in a Raman spectrum.