Proton exchange membrane (pem) electrochemical cell having an integral, electrically-conductive, resiliently compressible, porous pad

Abstract

Electrolysis cell comprises, in one embodiment, a proton exchange membrane (PEM), an anode positioned along one face of the PEM, and a cathode positioned along the other face of the PEM. A multi-layer metal screen for defining a first fluid cavity is placed in contact with the outer face of the anode, and an electrically-conductive, compressible, spring-like, porous pad for defining a second fluid cavity is placed in contact with the outer face of the cathode. The porous pad comprises a mat of carbon fibers bound together with one or more, preferably thermoplastic, resins, the mat having a density of about 0.2-1.5 g/cm. Cell frames are placed in peripheral contact with the metal screen and the compression pad for peripherally containing fluids present therewithin. Electrically-conductive separators are placed in contact with the metal screen and the compression pad for axially containing fluids present therewithin. A plurality of the cells may be arranged in series in a bipolar configuration without requiring a separate compression pad between cells (for gas pressure differentials up to about 400 psi or greater). The invention is also directed to a fuel cell wherein the pad replaces the carbon fiber paper or carbon fiber cloth in contact with the cathode or anode.