Patent ID: 7781088
Filing Date: 2010-08-24
Classification: H01M,Y02E,Y02P

Abstract:
1. A non-aqueous electrolyte secondary battery comprising: an outer can having an opening; an electrode assembly housed in the outer can, the electrode assembly comprising a positive electrode having a positive electrode current collector and a negative electrode having a negative electrode current collector; a sealing plate sealing the opening; a current collecting tab connected to one of the positive electrode current collector and the negative electrode current collector; an external electrode terminal projecting outside the sealing plate; a diaphragm disposed inside the sealing plate and outside the current collecting tab in the battery, the diaphragm being electrically connected to the external electrode terminal and deforming toward an outside of the battery when a battery internal pressure increases; a fragile portion connected at a center portion thereof to an inner surface of the diaphragm and also connected at a periphery thereof to the current collecting tab disposed below the diaphragm, the fragile portion breaking when the diaphragm deforms and rises upward, thereby interrupting current flow to the diaphragm; a current collecting tab holder into which a part of the current collecting tab is inserted, wherein the current collecting tab includes a planar insert member having the fragile portion and a current collector connecting portion connected to one of the positive electrode current collector and the negative electrode current collector; the current collecting tab holder is insulating and has a tab receiving portion into which an insert member of the current collecting tab is inserted, the tab receiving portion is provided on both an inner surface and an outer surface thereof with a holder hole, the holder hole overlapping with the fragile portion when the insert member is inserted; the diaphragm is disposed outside the tab receiving portion so as to cover the holder hole and is electrically connected at a center bottom thereof to the fragile portion via the holder hole; the external electrode terminal is swaged and fitted to a hole provided in the sealing plate via a gasket and an insulating plate; the current collecting tab holder is a different member from the gasket and the insulating plate; and wherein the diaphragm, external electrode terminal and current collecting tab holder are aligned in a plane that is perpendicular to the sealing plate.