Patent ID: 6713217
Filing Date: 2004-03-30
Classification: H01M,Y02E,Y02P

Abstract:
A nonaqueous electrolyte secondary battery comprising:a positive electrode comprising a positive active substance; a separator comprising a polyolefin group microporous membrane of 15 to 30 &mgr;m in thickness, with an endothermic calorie per unit area by the heat of fusion of at least 0.07 cal/cm2 in a temperature range of 70 to 150Â° C.; and a negative electrode comprising a carbon material which is at least one of artificial graphite powder or natural graphite powder, the carbon material having a plane interval (d002) of (002) plane by X-ray diffraction of less than 3.380 A and a specific surface area by BET method of 2.0 m2/g or more and less than 8.0 m2/g; wherein said separator absorbs heat generated by said negative electrode.