International Fuel Cells, LLC

United Technologies Corporation

Utc Fuel Cells, LLC

Ronald G Martin

Robert P Roche

Richard D Breault

Albert P Grasso

John C Trocciola

Joseph Powers

Warren L Luoma

Michael E Gorman

Myron Krasij

Bryan F Dufner

Daniel W Beal

Gregory R Kline

Joseph J O'Brien

Glen W Scheffler

A sealant system for a manifold of a proton exchange membrane fuel cell includes low temperature cured or heat cured silicone rubber bridges between the end plates to compensate for the uneven edges of various fuel cell component layers, and a layer of silicone rubber foam or sponge, or a molded silicone rubber gasket extending across the bridges and along the end plates, around the entire contact perimeter surfaces of the manifold, to seal the manifold to the fuel cell. The cured silicone rubber may extend along the end plates between the bridges. A rubber strip may be adhered to the silicone rubber bridges and end plates. The bridges may comprise a first layer of low shrinkage self-leveling RTV liquid rubber with viscosity in the range of 10,000-20,000 cps and a second layer of RTV liquid rubber.

Proton exchange membrane fuel cell external manifold seal

The coolant plate component of a fuel cell assembly is formed from a plate made from graphite particles that are bonded together by a fluorocarbon polymer binder and which encapsulate a serpentine coolant circulation tube. The coolant plate component is non-porous. The graphite particles are preferably flakes which pack together very tightly, and require only a minor amount of the polymer binder to form a solid plate. The plate will provide enhanced heat transfer, will conduct electrons, and will block electrolyte migration from cell to cell in a fuel cell stack due to its construction. The composition of the plate is graded so as to provide a varied coefficient of thermal expansion as measured through the thickness of the plate so as to reduce thermal stresses imposed on the fuel cell stack. The coolant circulation tube has a roughened outer surface which enhances adhesion of the encapsulating graphite flake/binder mixture without inhibiting heat transfer.

Coolant plate assembly for a fuel cell stack

The graphitized composite article of the present invention is formed by embedding carbon fiber felt in a matrix of a carbon filler; a thermosetting resin and a solvent; curing the composite article; then, carbonizing and graphitizing the cured composite article to form the graphitized composite article for use as a separator plate capable of substantially inhibiting mixing of hydrogen and oxygen and/or the loss of electrolyte within a fuel cell stack. The graphitized composite article may be a graphitized laminate.

Composite article

The reactant flow field on the cathode side of a fuel cell assembly is formed from a plate made from carbon particles that are bonded together by a fluorocarbon polymer binder. The cathode reactant flow field is non-porous, and is hydrophobic due to the presence of the poller binder. The carbon particles are preferably carbon flakes which pack together very tightly, and require only a minor amount of the polymer binder to form a solid plate. The plate will provide cathode reactant flow channels, will conduct electrons and heat and will minimize acid absorption in a fuel cell stack due to its hydrophobic nature.

Cathode reactant flow field component for a fuel cell stack

A fuel cell component that includes a porous fuel cell plate and a solid frame contiguously extending all around the fuel cell plate is made by first forming an integral plate-shaped porous body including a central portion constituting the fuel cell plate and a peripheral portion integral with and circumferentially completely surrounding the central portion, and then impregnating the pores of only the peripheral portion with a quantity of initially flowable but solidifiable impregnating material such that the impregnating material is accommodated in and completely fills such pores and makes the peripheral portion solid and completely fluid-impermeable upon solidification of the impregnating material to constitute the frame.

Plate-shaped fuel cell component

A composite plate-shaped fuel cell component includes two electrically conductive porous plates juxtaposed and in area electrical contact with one another at an interface, and a sealant body accommodated in and completely filling the pores of a sealed region of each of the porous plates that extends to a predetermined distance from the interface into the respective porous plate to form a fluid impermeable barrier between the porous plates and to bond the porous plates to one another at the interface. The sealant body includes at least one layer of a fluoroelastomer sealant that fills all of the pores of at least one of the sealed regions.

Method of manufacturing a laminated fuel cell component with an internal

A seal structure 58 between adjacent porous plates 18, 20 and a method of making the seal structure for an electrochemical cell are disclosed. Various construction details are developed which facilitate fabrication and assembly. In one embodiment, the adjacent porous plates are electrolyte reservoir plates joined together at a three-layer seal structure to form an integral assembly.

Electrochemical cell assembly

A seal structure 58 between adjacent porous plates 18,20 and a method of making the seal structure for an electrochemical coil are disclosed. Various construction details are developed which facilitate fabrication and assembly. In one embodiment, the adjacent porous plates are electrolyte reservoir plates joined together at a three-layer seal structure to form an integral assembly.

Method for making a seal structure for an electrochemical cell assembly

A matrix for holding the electrolyte within a phosphoric acid fuel cell is made from silicon carbide and a binder of polyestersulfone. Preferably the matrix consists of 10-20 weight percent polyethersulfone with a balance of silicon carbide. The matrix has improved strength, wettability and bubble pressure compared to the best known prior art matrix.

Silicon carbide matrix for fuel cells

A seal material especially adapted for phosphoric acid fuel cell stack sealing is described comprising an unfilled, unoiled high molecular weight polytetrafluoroethylene. Although the seal material is especially adapted as the regular seal around the plenums separating the oxygen and hydrogen gas inlets and outlets, it can also be used as a plenum or stack crack sealer. The material provides seal integrity and stability at temperatures in excess of 400.degree. F. (204.degree. C.)., e.g. 400.degree. F. to 450.degree. F. (204.degree. C. to 232.degree. C.), in a corrosive chemical environment at differential pressures above 50 psi (e.g. 50 psi to 80 psi). It can be used in electrochemical cells in general where high temperature, high pressure, corrosive environments prevail.

High temperature, high pressure chemical resistant seal material

A thermally conductive caulk particularly suited for use in a phosphoric acid fuel cell is made by mixing graphite into a stable aqueous dispersion of polytetrafluoroethylene and fluorinated ethylene propylene such that the solids floc to form a paste. The paste is applied to the part to be caulked and then dried and heat treated. Caulks made according to the present invention have good thermal conductivity and absorb very little phosphoric acid.

Growing community of inventors

Monson, MA, United States of America

Ronald G Martin