SECONDARY BATTERY TOP COVER ASSEMBLY, SECONDARY BATTERY AND VEHICLE

The present disclosure provides a secondary battery top cover assembly, a secondary battery and a vehicle. The top cover assembly includes: a top cover plate; an electrode terminal; and a short-circuit component including a deformable plate and a conductive plate disposed above the deformable plate. The deformable plate is connected to the top cover plate, and the conductive plate is connected to the electrode terminal. The conductive plate includes a body portion and a protrusion portion protruding upwardly from the body portion, the conductive plate is provided with a gas hole, and the gas hole cuts through the protrusion portion and the body portion, an inner wall of the gas hole includes an arc-shaped smooth transition portion.