An end cover assembly may include an end cover and an electrode terminal. The end cover may have an abutting surface. A terminal assembly may include the electrode terminal and a connector, where the connector may be configured to connect the electrode terminal and the end cover so as to fix the electrode terminal to the end cover, and the connector abuts against the abutting surface. The abutting surface may be provided with a concave portion recessed in a thickness direction of the end cover, and the concave portion may be configured to accommodate a part of the electrode terminal.