An electrochemical cell including a cell housing 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, an electrode assembly disposed in the cell housing, the electrode assembly including 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, and a current collector device that 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, wherein the first housing portion comprises a base and a sidewall that protrudes from a perimeter of the base and surrounds the base to form an open-ended container, the stack axis extends in a direction perpendicular to the base, the opening is formed in the sidewall at a location spaced apart from the sealed joint and at a location facing the stack axis, and the current collector device includes 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 and, a terminal plate that is oriented parallel to the sidewall, overlies the opening and is disposed outside the cell housing, the terminal plate directly contacting the current collecting plate via the opening so as to form an electrical connection with the current collecting plate. a cell housing 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, an electrode assembly disposed in the cell housing, the electrode assembly including 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, and a current collector device that 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, wherein the first housing portion comprises a base and a sidewall that protrudes from a perimeter of the base and surrounds the base to form an open-ended container, the stack axis extends in a direction perpendicular to the base, the opening is formed in the sidewall at a location spaced apart from the sealed joint and at a location facing the stack axis, and the current collector device includes 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 and, a terminal plate that is oriented parallel to the sidewall, overlies the opening and is disposed outside the cell housing, the terminal plate directly contacting the current collecting plate via the opening so as to form an electrical connection with the current collecting plate. 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 and, a terminal plate that is oriented parallel to the sidewall, overlies the opening and is disposed outside the cell housing, the terminal plate directly contacting the current collecting plate via the opening so as to form an electrical connection with the current collecting plate.