NOVELTY - The sealed nonaqueous electrolyte secondary battery comprises: an electrode assembly having a positive electrode and a negative electrode; a nonaqueous electrolyte containing a gas generator that is decomposed to generate a gas when a prescribed battery voltage is exceeded; and a battery case (50) that houses the electrode assembly and the nonaqueous electrolyte and comprises a current interrupt device that operates when a pressure within the battery case rises accompanying the gas generation. The positive electrode is provided with a positive electrode current collector.    USE - The sealed nonaqueous electrolyte secondary battery is useful as a single cell in a battery pack as a vehicle drive power source formed by electrically interconnecting single cells (all claimed), and as a portable power source for personal computers and portable terminals, where the vehicle is plug-in hybrid vehicles, hybrid vehicles and electric vehicles.    ADVANTAGE - The sealed nonaqueous electrolyte secondary battery is smaller in size, has lightweight, high energy density and good output density, and realizes a reduced battery resistance and a high reliability in terms of ensuring the generation of an adequate amount of gas during a pressure rise within the battery case.    DETAILED DESCRIPTION - The sealed nonaqueous electrolyte secondary battery comprises: an electrode assembly having a positive electrode and a negative electrode; a nonaqueous electrolyte containing a gas generator that is decomposed to generate a gas when a prescribed battery voltage is exceeded; and a battery case (50) that houses the electrode assembly and the nonaqueous electrolyte and comprises a current interrupt device that operates when a pressure within the battery case rises accompanying the gas generation. The positive electrode is provided with a positive electrode current collector and a positive electrode mixture layer containing a positive electrode active material and formed on the positive electrode current collector. The positive electrode mixture layer contains, as conductive agents, electroconductive carbon particles and an expanded graphite. The expanded graphite (50 mass%) in the positive electrode mixture layer is arranged in a state in which an angle formed between the (002) plane of the expanded graphite and a surface of the positive electrode current collector is 60 degrees . The carbon particles have an average pore diameter of 0.1-5 mu m. An amount of addition of the expanded graphite in the positive electrode mixture layer is larger than an amount of addition of the carbon particles in the positive electrode mixture layer. An INDEPENDENT CLAIM is included for a method of producing a sealed nonaqueous electrolyte secondary battery.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic, perspective view of an outer shape of a sealed nonaqueous electrolyte secondary battery.    Battery cases (50)    Battery case main body (52)    Lid (54)    Positive electrode terminal (70)    Negative electrode terminals. (72)