Top cap assembly of a secondary battery, and secondary battery

A top cap assembly of a secondary battery, comprising:

• a top cap plate having an electrode extraction hole;
• an electrode terminal comprising a terminal plate, wherein the terminal plate covers the electrode extraction hole;
• a first fixing component, at least partially surrounding the terminal plate to fix the electrode terminal to the first fixing component;
• and
• a second fixing component comprising a main body and a first connection portion, wherein the first connection portion is connected to the main body and extends away from the terminal plate, the main body is fixedly connected to the first fixing component, and the first connection portion is fixedly connected to the top cap plate,
• wherein the electrode terminal is separated from the second fixing component through the first fixing component, the terminal plate, the first fixing component and the second fixing component are located on a same side of the top cap plate away from inside of a case of the secondary battery.