Battery pack and portable electronic device

摘要

The present invention includes a plurality of battery cells, each provided with a gas discharge valve. A housing accommodates the battery cells and has a gas opening. The housing does not melt at an inside temperature of the battery pack increased by gas discharged from the gas discharge valve. A blocking member blocks the gas opening and melts at the inside temperature of the battery pack increased by the gas discharged from the gas discharge valve, breaching the gas opening.