A metal support disk useful in sealing an electrochemical cell exerts a resilient outward radial force against the seal to assure seal integrity over a wide temperature range and exerts an upward force against an adjacent metal end cap terminal to assure continued mechanical and electrical contact with the terminal. The support is a stepped disk having a centrally located, shallow, cylindrical pill-box, with the bottom of the pill-box extending radially outward into an annular ring. A spring means in the form of an S-shaped rim extends down from the periphery of the ring, terminating at its bottom in an outward extending flange. The edge of the flange presses a plastic seal member against the inside wall of the cell to form the seal.