Abstract: This invention relates to the discovery that during operation and/or shutdown of electrochemical and gas generating devices corrosive materials are released from hardware and components employed therein and that such materials are principally responsible for observed pitting and perforation failure of the metallic hardware, including the separator/collector sheets, of these devices that serve to partition and hermetically seal compartments that support a hydrogen atmosphere. This invention therefore particularly relates to a method for improving the reliability of such devices by reducing brittle failure and perforation failure of these separator sheets by providing a composite separator sheet made up of a layer of a material resistant to molecular hydrogen embrittlement adhered to a layer of a corrosion resistant material.