Mechanically fastened through-wall current collector

A battery pack comprising electrochemical cells, each electrochemical cell including a cell housing, an electrode assembly disposed in the cell housing, and a current collector device, wherein

• the cell housing is formed of a flexible sheet, the cell housing having a first housing portion, and a second housing portion that is joined to the first housing portion along a sealed joint to form a pouch, the first housing portion comprising a base and a sidewall that protrudes from a perimeter of the base and surrounds the base to form an open-ended container,
• the electrode assembly includes positive electrode portions alternating with negative electrode portions, the positive electrode portions and the negative electrode portions being separated by at least one separator and stacked along a stack axis, the stack axis extending in a direction perpendicular to the base, and
• the current collector device is electrically connected to one of the positive electrode portions and the negative electrode portions and exits the cell housing via an opening formed in the cell housing sidewall, the opening disposed at a location spaced apart from the sealed joint and at a location facing the stack axis, the current collector device including
• a current collecting plate that is disposed between the sidewall and the one of the positive electrode portions and the negative electrode portions, is electrically connected to the one of the positive electrode portions and the negative electrode portions, is oriented parallel to the sidewall, and overlies the opening, the current collecting plate including a protrusion that protrudes from a sidewall facing surface of the plate and extends through the opening,
• a seal that surrounds the opening and is disposed between the sidewall and the current collecting plate, and
• a terminal plate that is oriented parallel to the sidewall, overlies the opening and is disposed outside the cell housing, the terminal plate including a port that overlies the opening and receives the protrusion, and the port is configured to engage with the protrusion in such a way that the port of the terminal plate directly contacts the protrusion of the current collecting plate so as to form an electrical connection with the current collecting plate, and in such a way that the seal is compressed between the sidewall and the current collecting plate, and
• a portion of the current collector device of one of the electrochemical cells directly contacts and forms an electrical connection with a portion of a current collector device of an adjacent electrochemical cell.