International Fuel Cells, LLC

Utc Fuel Cells, LLC

Clearedge Power Corporation

Utc Power Corporation

Robert P Roche

Ronald G Martin

Richard D Breault

Albert P Grasso

John C Trocciola

Paul R Margiott

Warren L Luoma

Gregory R Kline

Joseph J O'Brien

Glen W Scheffler

Michael P Nowak

A fuel cell separator plate assembly () includes a separator plate layer () and flow field layers (). In one disclosed example, the separator plate layer () comprises graphite and a hydrophobic resin. The hydrophobic resin of the separator plate layer () serves to secure the separator plate layer to flow field layers on opposite sides of the separator plate layer. In one example, at least one of the flow field layers () comprises graphite and a hydrophobic resin such that the flow field layer is hydrophobic and nonporous. In another example, two graphite and hydrophobic resin flow field layers are used on opposite sides of a separator plate layer. One disclosed example includes all three layers comprising graphite and a hydrophobic resin.

Fuel cell separator plate assembly

Fuel mixing control arrangements are provided for fuel cell power plants () operating on multiple fuels (). A fuel delivery system () supplies hydrogen-rich fuel () to the cell stack assembly (CSA) () after controlled mixing of a primary fuel () and at least a secondary fuel (), each having a respective 'equivalent hydrogen (H) content'. The relative amounts of the primary fuel () and secondary fuel () mixed are regulated () to provide at least a minimum level (LL) of hydrogen-rich fuel having an equivalent hydrogen content sufficient for normal operation of the CSA (). The primary fuel () is a bio-gas or the like having a limited, possibly variable, equivalent Hcontent, and the secondary fuel () has a greater and relatively constant equivalent H2 content and is mixed with the primary fuel in an economic, constant relationship that assures adequate performance of the CSA (). One or more parameters (IDC, P, V, E. C.) of the operating power plant () related to the equivalent Hcontent of at least the primary fuel may be sensed () and used to control () the relative amounts of secondary and primary fuels () mixed in response thereto.

Fuel mixing control for fuel cell power plants operating on multiple fuels

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 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

Electrolyte migrates inter-cell in fuel cell stacks due to an electric potential gradient across the stack. This migration can be substantially inhibited with a graphite separator plate which has been laminated to the electrolyte reservoir plates of adjacent fuel cells with a fluoropolymer resin. In such an arrangement, the fluoropolymer resin forms an electrolyte barrier between the graphite separator plate while maintaining an electrically conductive pathway between the electrolyte reservoir plate and the graphite separator plate.

Fluoropolymer laminated separator plate

A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of porous plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A separator plate is interposed between each two successive electrodes of adjacent ones of the fuel cells and is unified therewith into an integral separator plate by forcing most of a quantity of an electrolyte-nonwettable material, which is originally introduced into the respective interface as a sheet of such material, into the pores of the respective electrodes. A circumferentially complete barrier that prevents flow of shunt currents onto and on an outer peripheral surface of the separator plate is formed by extruding the remainder of the electrolyte-nonwettable material out of the respective interface. This carrier also prevents cell-to-cell migration of any electrolyte that may be present at the outer periphery of the integral separator plate while the latter is incorporated in the fuel cell stack.

Extruded fuel cell stack shunt current prevention arrangement

A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A separator plate is interposed between each two successive electrodes of adjacent ones of the fuel cells and is unified therewith into an integral separator plate. Each integral separator plate is provided with a circumferentially complete barrier that prevents flow of shunt currents onto and on an outer peripheral surface of the separator plate. This barrier consists of electrolyte-nonwettable barrier members that are accommodated, prior to the formation of the integral separator plate, in corresponding edge recesses situated at the interfaces between the electrodes and the separator plate proper. Each barrier member extends over the entire length of the associated marginal portion and is flush with the outer periphery of the integral separator plate. This barrier also prevents cell-to-cell migration of any electrolyte that may be present at the outer periphery of the integral separator plate while the latter is incorporated in the fuel cell stack.

Growing community of inventors

Cheshire, CT, United States of America

Robert P Roche