Battery

A battery, comprising:

• an electrode body;
• and
• a laminate exterior body accommodating the electrode body at an interior thereof, wherein:
• the laminate exterior body has a mechanism switchable between a closed state of closing the interior and an open state of opening the interior to an exterior of the laminate exterior body,
• the mechanism switches from the closed state to the open state when a pressure of the interior of the laminate exterior body exceeds a threshold value,
• the laminate exterior body has a rectangular parallelepiped shape,
• the laminate exterior body has, in plan view, a pair of first sides extending in a first direction and a pair of second sides extending in a second direction orthogonally intersecting the first direction,
• the mechanism is positioned within a virtual region enclosed by a pair of first virtual straight lines including the pair of first sides and by a pair of second virtual straight lines including the pair of second sides, and
• a length of the mechanism is shorter than a length of the laminate exterior body in a third direction orthogonally intersecting each of the first direction and the second direction.