Electrochemical device comprising an electrically-conductive, selectively-permeable membrane

摘要

An electrochemical device, such as a fuel cell or an electrolyzer. In one embodiment, the electrochemical device includes a membrane electrode assembly (MEA), an anodic gas diffusion medium in contact with the anode of the MEA, a cathodic gas diffusion medium in contact with the cathode, a first bipolar plate in contact with the anodic gas diffusion medium, and a second bipolar plate in contact with the cathodic gas diffusion medium. Each of the bipolar plates includes an electrically-conductive, non-porous, liquid-permeable, substantially gas-impermeable membrane in contact with its respective gas diffusion medium, the membrane including a solid polymer electrolyte and a non-particulate, electrically-conductive material, such as carbon nanotubes, carbon nanofibers, and/or metal nanowires. In addition, each bipolar plate also includes an electrically-conductive fluid chamber in contact with the electrically-conductive, selectively-permeable membrane and further includes a non-porous and electrically-conductive plate in contact with the fluid chamber.

主权项

1. An electrochemical device comprising:
(a) a polymer electrolyte membrane, said polymer electrolyte membrane having opposing first and second faces; (b) an anode electrically coupled to the first face of said polymer electrolyte membrane; (c) a cathode electrically coupled to the second face of said polymer electrolyte membrane; (d) an anodic gas diffusion medium defining an anode chamber in fluid communication with said anode, said anodic gas diffusion medium having opposing first and second faces, said first face facing towards said anode; (e) a cathodic gas diffusion medium defining a cathode chamber in fluid communication with said cathode, said cathodic gas diffusion medium having opposing first and second faces, said first face facing towards said cathode; and (f) a first membrane, said first membrane being in contact with said second face of said anodic gas diffusion medium, said first membrane being electrically-conductive, non-porous, permeable to liquids, and substantially impermeable to gases, and comprising a solid polymer electrolyte and a non-particulate, electrically-conductive material, wherein said non-particulate, electrically-conductive material comprises carbon nanotubes, wherein said carbon nanotubes have an aspect ratio in the range of about 5 to about 1,000,000, wherein said carbon nanotubes are aligned in a film sheet direction, and wherein said first membrane is prepared by a process comprising mixing said carbon nanotubes in a dispersion of the solid polymer electrolyte to yield an ink, then coating the ink onto a substrate by solvent-casting to form a coated substrate, and then heat-pressing the coated substrate to form a film.