Battery

A battery comprising:

• a bottomed cylindrical case body that accommodates an electrode body;
• and
• a bottom-portion insulating plate that is disposed between the electrode body and a bottom portion of the case body,
• wherein the bottom portion of the case body has a gas discharge port that opens when an internal pressure of the battery reaches a predetermined pressure,
• wherein the bottom-portion insulating plate has a plurality of through holes,
• wherein an aperture ratio, which is a ratio of an area of the through hole with respect to a total area of the insulating plate, is greater than or equal to 10% and less than or equal to 40%, and
• wherein a Young's modulus of the bottom-portion insulating plate at 25° C. is 10 GPa or greater, and
• wherein the plurality of the through holes include a first through hole and a plurality of second through holes, the first through hole being formed in a range including a center of the bottom-portion insulating plate, the plurality of second through holes being formed around the first through hole,
• wherein a diameter of a circle, which is a circle whose radius extends from the center of the bottom-portion insulating plate to inner edges of the second through holes that are closest to the center is smaller than a diameter of the gas discharge port,
• wherein a portion of the plurality of second through holes is located out of peripheral edge of the gas discharge port.