Patent ID: 8158284
Filing Date: 2012-04-17
Classification: H01M,Y02E,Y02T

Abstract:
1. A lithium ion secondary battery comprising a positive electrode of absorbing/releasing lithium, a negative electrode of absorbing/releasing lithium and an electrolyte, wherein the negative electrode has a negative electrode active material, the negative electrode active material contains a non-graphitizing carbon and a graphitizing carbon which is coated on the surface with the non-graphitizing carbon, the non-graphitizing carbon is in the range from 90 to 50 wt % and the graphitizing carbon is in the range from 10 to 50 wt % based on the total weight of the non-graphitizing carbon and the graphitizing carbon, with the total of them being 100%, and the average grain size of the graphitizing carbon is larger than the average grain size of the non-graphitizing carbon.