Battery packaging material having a valve device

A battery comprising:

• a battery element;
• a housing body that is constituted by at least one laminate including at least a base material layer, a barrier layer, and a heat-sealable resin layer layered in that order and houses the battery element;
• and
• a valve device that is in communication with the inside of the housing body,
• wherein sections of the heat-sealable resin layer of the at least one laminate face each other in a peripheral edge portion of the housing body,
• a joined edge portion in which the mutually facing sections of the heat-sealable resin layer of the at least one laminate are fused together is formed in the peripheral edge portion of the housing body,
• the valve device includes:
• a first portion in which a valve mechanism is formed, the valve mechanism being configured to reduce an internal pressure of the housing body if the internal pressure is increased due to gas generated in the housing body;
• and
• a second portion in which an air passage is formed, the air passage being configured to guide gas generated in the housing body toward the valve mechanism,
• the first portion is located on an outer side of an outer edge of the joined edge portion,
• at least a portion of the second portion is sandwiched between the sections of the heat-sealable resin layer of the at least one laminate in the joined edge portion,
• a length of the second portion in a width direction of the battery is longer than a length of the second portion in a thickness direction of the battery,
• an outer contour of the joined edge portion by the heat-sealable resin layers at a peripheral joint in contact with a portion of the second portion includes a straight line, and
• wherein a length of the air passage of the second portion in a width direction of the battery is longer than a length of the air passage of the second portion in a thickness direction of the battery, where the width direction is transverse to a longitudinal axis of the second portion.