Rechargeable battery

A rechargeable battery is disclosed. The battery includes an electrode assembly having an uncoated region and an insulation plate disposed on the uncoated region of the electrode assembly. The battery also includes a gasket formed on the insulation plate, wherein the gasket comprises a bottom surface contacting an upper surface of the insulation plate and at least one side surface extending from the bottom surface, and wherein and the at least one side surface of the gasket (40) forms an obtuse angle with respect to the upper surface of the insulation plate (50, 250, 350). The battery optionally includes a cap assembly contacting the gasket and connected to the uncoated region of the electrode assembly through a lead tab.