International Fuel Cells, LLC

United Technologies Corporation

Clearedge Power Corporation

Other

The United States of America as Represented by the United States

Utc Fuel Cells, LLC

Donald L Maricle

Carl Anthony Reiser

Yang Song

Craig E Evans

John C Trocciola

Leslie L Van Dine

Zakiul Kabir

Lin Qiu

Dennis C Nagle

Harry L Tuller

Ned Emidio Cipollini

Glenn W Scheffler

Michael E Gorman

Richard F Buswell

Murray Katz

Craig R Schroll

Stanley P Bonk

Lawrence J Bregoli

Robert C Stewart, Jr

Thomas E Swarr

John M Lee

Martin L Abrams

George A Louis

Gary C Putnam

Howard S Carr

A method is provided for reducing degradation in a fuel cell assembly, including at least one fuel cell with a PBI membrane, during standby, operation. The method may include electrochemically consuming an oxidant from a cathode coupled to the PBI membrane in response to a disconnection of an external load and supplying fuel to remove or electrochemically consume any back-diffused oxidant to the associated fuel cell sufficient to replace or consume the back-diffused oxidant while the external load is removed, and/or also may include controlling a standby temperature of the fuel cell. In this way, it may be possible to avoid increased cell voltage decay associated with degradation of the PBI in a simple and cost effective system.

System and method for operating a high temperature fuel cell as a back-up power supply with reduced performance decay

An improved water management system for PEM fuel cells is provided. Catalyst layers are disposed on both sides of a proton exchange membrane. Porous plates are positioned adjacent the catalyst layers. Water transport plates are positioned adjacent the porous plates and the reactant gas are humidified at their inlets, in one embodiment by fins, while moisture is removed in the fuel flow path and at the oxidant outlet, in one embodiment by other fins.

Water management system for fuel cell

A fuel cell (,), having a proton exchange membrane (,), an anode and a cathode, and cathode and anode water transport plates (,), includes a water capillary edge seal to optimize and greatly improve fuel cell operation without the need for additional seals or impregnation of the water transport plates. The water filled porous bodies of the water transport plates (,) use the capillary forces of the water, which is a product of the electrochemical reaction of the fuel cell (,) and the preferred coolant, to prevent gas intrusion into the water system and over board leakage of the gases as well as the resultant hazardous mixture of gaseous fuel and oxidizing gas.

Fuel cell with water capillary edge seal

A polymer electrolyte membrane fuel cell includes an anode chamber and a cathode chamber which are separated by the electrolyte membrane. The fuel cell directly oxidizes a liquid methanol fuel which is fed into the anode chamber from a liquid methanol storage container. The liquid methanol is mixed with water in the anode chamber, and the mixture passes into and through the electrolyte membrane. Some of the methanol and water pass through the membrane into the cathode chamber and into a process air stream which moves through the cathode chamber. The methanol and water are removed from the cathode chamber by evaporation into the process air stream, which then is directed into a condenser/radiator. The methanol and water vapors are condensed in the condenser/radiator, from whence the condensed water and methanol are returned to the anode chamber of the cell. The evaporating cathode process air stream provides oxygen for the fuel cell reaction, and also cools the cell.

Direct methanol oxidation polymer electrolyte membrane power system

The reactant manifolds and corners of a molten carbonate fuel cell stack are sealed with particulate lithium aluminate members which are sufficiently porous so as to resist significant electrolyte migration therethrough. The seal members which are disposed in vertical planes of the stack are preferentially formed from lithium aluminate grains which are bonded together by a silica-free glass binder. The seal members which are disposed in horizontal planes in the stack are preferably formed from lithium aluminate grains which are bonded together by surface hydrolysis. Alumina-clad stainless steel labyrinth seal members are associated with each of the horizontal seal members to inhibit electrolyte migration from the cell electrolyte matrices to the vertical seal members.

Edge seals for molten carbonate fuel cell stacks

A ceria electrolyte composition is disclosed. The composition provides high ionic conductivity and low electronic conductivity under reducing conditions. Fuel cells employing the disclosed composition exhibit improved efficiency and power density.

Ceria electrolyte composition

A fuel cell has a current collector plate (22) located between an electrode (20) and a separate plate (25). The collector plate has a plurality of arches (26, 28) deformed from a single flat plate in a checkerboard pattern. The arches are of sufficient height (30) to provide sufficient reactant flow area. Each arch is formed with sufficient stiffness to accept compressive load and sufficient resiliently to distribute the load and maintain electrical contact.

Fuel cell current collector

The fuel cell stack is made from two basic finished component subassemblies which are stacked repetitively atop each other in alternating fashion. One of the components is an electrode subassembly, and the other is a separator plate-flow field subassembly. The subassemblies are formed from several different material layers which are sintered and shrunk to operating size and density prior to the stack being assembled. The finished subassemblies are layered atop each other to form the stack and then heated to an elevated subsintering temperature and subjected to a light compressive load so that abutting surfaces of the adjacent subassemlies are creep flattened into intimate adherent contact with each other thereby forming a monolithic stack assembly.

Method of making monolithic solid oxide fuel cell stack

An electrochemical cell electrode is produced by applying a plurality of thin layers of a catalyst material onto a substrate, filtering and compacting the layers between additions, until a desired catalyst amount is achieved. The catalyst bearing substrate is then dried and sintered to form an electrode. Utilizing a serial application technique minimizes surface cracking while maximizing throughput by allowing automation of the electrode production process.

Method of making an electrochemical cell electrode

A fuel cell stack is disclosed with modified electrolyte matrices for limiting the electrolytic pumping and electrolyte migration along the stack external surfaces. Each of the matrices includes marginal portions at the stack face of substantially greater pore size than that of the central body of the matrix. Consequently, these marginal portions have insufficient electrolyte fill to support pumping or wicking of electrolyte from the center of the stack of the face surfaces in contact with the vertical seals. Various configurations of the marginal portions include a complete perimeter, opposite edge portions corresponding to the air plenums and tab size portions corresponding to the manifold seal locations. These margins will substantially limit the migration of electrolyte to and along the porous manifold seals during operation of the electrochemical cell stack.

Electrolyte matrix in a molten carbonate fuel cell stack

A molten carbonate fuel cell matrix material is described made up of a matrix tape portion and a bubble barrier portion. The matrix tape portion comprises particles inert to molten carbonate electrolyte, ceramic particles and a polymeric binder, the matrix tape being flexible, pliable and having rubber-like compliance at room temperature. The bubble barrier is a solid material having fine porosity up to about 50% by volume, optionally being bonded to the matrix tape. In operation in a fuel cell, the polymer binder burns off leaving the matrix and bubble barrier providing superior sealing, stability and performance properties to the fuel cell stack.

Molten carbonate fuel cell integral matrix tape and bubble barrier

A method of making a thin, flexible, pliable matrix material for a molten carbonate fuel cell is described. The method comprises admixing particles inert in the molten carbonate environment with an organic polymer binder and ceramic particle. The composition is applied to a mold surface and dried, and the formed compliant matrix material removed.

Method of making molten carbonate fuel cell ceramic matrix tape

A molten carbonate fuel cell matrix material is described made up of a matrix tape portion and a bubble barrier portion. The matrix tape portion comprises particles inert to molten carbonate electrolyte, ceramic particles and a polymeric binder, the matrix tape being flexible, pliable and having rubber-like compliance at room temperature. The bubble barrier is a solid material having fine porosity preferably being bonded to the matrix tape. In operation in a fuel cell, the polymer binder burns off leaving the matrix and bubble barrier providing superior sealing, stability and performance properties to the fuel cell stack.

A new type of electrochemical cell which can be used for generating electricity or in an electrolysis mode for producing gases such as hydrogen and oxygen comprises laterally spaced apart or side-by-side catalyst layers as electrodes with the gap between the catalyst layers being bridged by a solid electrolyte which provides an ion conductive path from one catalyst layer to the other. The catalyst layers and the electrolyte are preferably in the form of thin films or layers on the surface of an inert supporting substrate. A plurality of these cells may be disposed on the substrate and interconnected electrically forming a network of series and parallel connected cells. Means are provided to feed fuel and oxidant to the electrodes either as separate gases or mixed together if appropriate catalytic materials are selected.

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Glastonbury, CT, United States of America

Donald L Maricle