| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery capable of reducing the possibility of an accidental explosion caused by rapid expansion on the periphery of a guide passage by safely guiding generated gas outside an electrode group and a battery case through the guide passage if rapid gas generation under a high temperature condition occurs concentratedly on one place locally. SOLUTION: In this nonaqueous electrolyte secondary battery, a first axis of the columnar electrode group 6 and a second axis of the columnar battery case 4 housing the electrode group 6 are slightly decentered without corresponding with each other. The decentering forms an air gap 20 between the inner wall of the battery case 4 and the outmost periphery of the electrode group 6. Letting (B-A)/T is K where A is the outside shape of the electrode group 6, T is thickness per layer of the electrode group, and B is the inside diameter of the battery case 4, K is set to 1.15-2.75 to ensure the sufficient capacity of the gas guide passage according to a place of gas generation if gas blows out from the electrode group 6, thus it is possible to reduce the risk of the nonaqueous electrolyte battery. COPYRIGHT: (C)2004,JPO |
