COVER ASSEMBLY OF SECONDARY BATTERY AND SECONDARY BATTERY

The present disclosure relates to the technical field of energy storage devices, and in particular, to a cover assembly of a secondary battery and a secondary battery. The cover assembly includes: a cover plate including a gas vent; a gas exhaust valve configured to seal the gas vent and deform in response to an increase in temperature to get out of a state of sealing the gas vent; and a protective part at least partially covering the gas vent and having a gas permeability coefficient smaller than a gas permeability coefficient of the gas exhaust valve. The cover assembly of the secondary battery and the secondary battery provided by the present disclosure seal the gas vent by the gas exhaust valve, and the gas exhaust valve deforms in response to an increase in temperature in such a manner that the gas exhaust valve no longer seals the gas vent. When temperature inside the case of the secondary battery rises, the gas inside the case can be exhausted via the gas vent, thereby reducing a risk of thermal runaway of the secondary battery, and also slowing down the thermal runaway of the secondary battery and thus providing passengers with sufficient escape times. The protective part improves an anti-penetration performance.