Patent ID: 6905796

Claim:
A non-aqueous lithium ion secondary battery comprising: a positive electrode comprising a lithium transition metal compound oxide; a negative electrode which is negative during discharging of the battery, the negative electrode comprising an active substance that occludes and releases lithium ions; a microporous polymer film separator between the positive electrode and the negative electrode; and a nonaqueous electrolyte solution comprising a nonaqueous solvent and a lithium salt dissolved therein; wherein: the negative electrode comprises ceramic particles not relating to the charge and discharge reactions of the battery; the negative electrode comprises 5 to 20 parts by weight of the ceramic particles in 100 parts by weight of the active substance; the ceramic particles are Al 2 O 3 particles; the lithium salt is LiPF 6 ; and the particle size of the ceramic particles is 1 micron or less.