COVER ASSEMBLY OF SECONDARY BATTERY AND SECONDARY BATTERY

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.