A case-neutral electrochemical cell has an electrode assembly comprising a separator positioned between an anode and a cathode housed inside a casing. The casing supports a co-axial glass-to-metal seal (GTMS) comprising an inner insulating glass hermetically sealed to a terminal pin and to the inner annular surface of an inner ferrule. An outer insulating glass is hermetically sealed to the outer annular surface of the inner ferrule and the inner annular surface of an outer ferrule. The outer ferrule is secured to an opening in the casing. Two methods are described for manufacturing a co-axial GTMS depending on the melting temperatures of the inner and outer insulating glasses. Then, one of the anode and the cathode is connected to the terminal pin and the other of the anode and the cathode is connected to the inner ferrule. An electrolyte is provided in the casing to activate the electrode assembly.