Patent ID: 7718293

Claim:
An electrochemical system comprising: an electrochemical cell stack having a layering of a plurality of electrochemical cells and including an electrochemically active region, said electrochemical cell stack being under mechanical compression in a direction of said layering of said plurality of electrochemical cells; a plurality of metallic bipolar plates separating said electrochemical cells from one another, said bipolar plates including openings for media for said electrochemical cells, said openings extending in a direction parallel with said direction of said layering of said plurality of electrochemical cells, at least one resilient bead arrangement around at least one of said openings, said at least one resilient bead arrangement being formed integrally as one piece with one of said plurality of metallic bipolar plates and including at least one flank extending in a direction that is not perpendicular to said direction of said layering of said plurality of electrochemical cells; at least one perforation through said at least one flank, said at least one perforation allowing the media that passes through said at least one of said openings in a direction parallel with said direction of said layering of said plurality of electrochemical cells to pass through the flank of the bead in a direction perpendicular to said direction of said layering of said plurality of electrochemical cells.