BATTERY PRODUCTION METHOD, BATTERY PRODUCTION APPARATUS, AND BATTERY

(a) An electrode assembly is accommodated in a laminated casing. (b) A pressure-applied portion is formed by sandwiching at least a portion of a peripheral edge of the laminated casing between a first tool and a second tool. (c) A sealed portion is formed by applying ultrasonic vibration from at least one of the first tool and the second tool to the pressure-applied portion. The first tool includes a projection portion. The second tool is provided with a groove portion. A bending tendency portion is formed in the laminated casing by sandwiching the laminated casing between a tip of the projection portion and a bottom portion of the groove portion. The laminated casing is welded on both sides across the bending tendency portion.