Utc Fuel Cells, LLC

Utc Power Corporation

Ballard Power Systems Corporation

Gennady Resnick

Carl Anthony Reiser

Kazuo Saito

Glenn Michael Allen

Harold T Couch

James Cameron

Ned Emidio Cipollini

David A Condit

Deliang Yang

Jung S Yi

Matthew P Wilson

Patrick L Hagans

Emily A Dykeman

Zebulon D Vance, Jr

Tadahiko Taniguchi

Akira Maekawa

Neil A Popovich

An exemplary method of treating a material such as carbon or graphite to render at least some surfaces of the material hydrophilic includes coating at least a portion of the at least some surfaces with an oxygenated element and controlling a rate of a breakdown of the oxygenated element to leave a corresponding elemental oxide on the surfaces. In one example, the material is treated before being incorporated into an article comprising the material. Another example method includes treating an article comprising the material. Disclosed examples include precipitation or decomposition as the breakdown of the oxygenated element.

Method of treating a material to achieve sufficient hydrophilicity for making hydrophilic articles

A fuel cell includes a membrane electrode assembly comprised of a membrane sandwiched between anode and cathode catalyst structures. An anode separator plate and a cathode separator plate are arranged adjacent to the membrane electrode assembly opposite from one another. The anode and cathode separator plates include opposing sides in which one of the opposing sides of the anode and cathode respectively have fuel and oxidant flow fields in communication with the membrane. The anode separator plate is a structure having a first water permeability and is configured to permit passage of water between its opposing sides and with its flow field, and the cathode separator plate comprises a structure having a second water permeability less than the first water permeability of the anode separator plate. In one example, the anode is provided by a porous separator plate, and the cathode is provided by a non-porous, or solid, plate.

Separator plate configuration for a fuel cell

Water in a fuel cell accumulator is kept above freezing by a hydrogen/oxygen catalytic combustor fed hydrogen through a mechanical thermostatic valve in thermal communication with the container and connected to a hydrogen supply. The system includes an ejector hydrogen/oxygen combustor and a diffusion hydrogen/oxygen combustor for warming a medium within a container such as water in the accumulator of a fuel cell in response to a mechanic hydrostatic valve which conducts hydrogen to a combustor responsive to the temperature of the container.

Catalytic combustors keeping contained medium warm in response to hydrostatic valve

The medium (), such as water, of a container (), such as a fuel cell accumulator, is kept above freezing by a hydrogen/oxygen catalytic combustor () fed hydrogen from a source comprising a mechanical thermostatic valve () in thermal communication () with the container () and connected to a hydrogen supply (). The combustor may comprise an ejector () having hydrogen through its primary inlet () drawing air through a secondary inlet (). The combustor may comprise a diffusion combustor having a catalyst () spaced from a heating surface () and a diffusion control plate () low partial pressure of oxygen at the catalyst causing diffusion through the barrier. Water vapor from combustion condenses on a surface () and is led by hydrophilic woven carbon paper () to wicking material (), which has smaller pores than the carbon paper, which leads the water downwardly, through a disk () and plugs () to atmospheric air. The noble metal catalyst mixture includes TEFLON&#xae; to permit water generated by combustion to flow by gravity out of the catalyst.

A cell stack assembly () coolant system comprises a coolant exhaust conduit () in fluid communication with a coolant exhaust manifold () and a coolant pump (). A coolant inlet conduit () enables transportation of the coolant to the coolant inlet manifold. The coolant system further includes a bypass conduit () in fluid communication with the coolant exhaust manifold and the coolant inlet manifold, while a bleed valve () is in fluid communication with the coolant exhaust conduit and a source of gas. Operation of the bleed valve enables venting of the coolant from the coolant channels, and through a shut down conduit (). An increased pressure differential between the coolant and reactant gases forces water out of the pores in the electrode substrates (). An ejector () prevents air form inhibiting the pump. Pulsed air is blown () through the coolant channels to remove more water.

Method and apparatus for the operation of a cell stack assembly during subfreezing temperatures

The air blower () of a fuel cell power plant () is used to force water out of the coolant flow fields () of a fuel cell stack (), a coolant pump () and a heat exchanger () through a valve () which is closed during normal operation. The water removal occurs as part of a shutdown procedure in which the fuel cell stack continues to operate so that it provides the power for the air pump and to assist in water removal (such as retaining low vapor pressure). The water flow to an accumulator () is blocked by a valve () during the shutdown procedure.

Purging water with reactant air pump powered by operational fuel cell system during shutdown

A plurality of fuel cell stacks () have their cathode ends () contiguous with either a common current collector () or respective current collectors () which may be separated by electrical isolation (). The cathode-to-cathode relationship protects the cathode of each of the stacks from cold ambient environments, thereby permitting improved cold starts and mitigation of performance loss as a result of cold starts as well as freeze/thaw cycles. Heaters () may be provided in current collectors, or in or between electrical isolation. Four stacks may share one current collector, or each may have its own current collector.

Cathode-to-cathode fuel cell stacks

A method for operating a fuel cell stack assembly having a plurality of fuel cells arranged in a stack to define opposed end fuel cells, wherein the plurality of fuel cells include intermediate fuel cells between the opposed end fuel cells, including feeding fuel and oxidant to the intermediate fuel cells whereby the at least one end fuel cell transports hydrogen across the cell and produces heat.

System and method for starting a fuel cell stack assembly at sub-freezing temperature

A method for shutting down a fuel cell system including a plurality of fuel cells arranged in a stack, includes cooling the fuel cells to a shutdown temperature while maintaining a substantially uniform water vapor pressure through the fuel cells whereby migration of water within the fuel cells during cooling is reduced.

Shutdown procedure to improve startup at sub-freezing temperatures

A PEM fuel cell system includes a plurality of PEM fuel cells arranged in a stack having two opposed, outwardly facing end surfaces; pressure plates positioned relative to said end surfaces for securing said PEM fuel cells in said stack; and spacer members between said end surfaces and said pressure plates for thermally insulating said end surfaces from said pressure plates.

End-cell thermal distancing for fuel cell system

Recovery of PEM fuel cell performance is achieved by evacuating ( ) or by flowing water absorbing gas ( ) through, or both, the fuel flow field ( ), the air flow field ( ), and the water flow field ( ), while resistance of the individual cells, or of the fuel cell stack, is measured; the dry out process is continued until the resistance of the cells (or the resistance per cell, measured across the fuel cell stack as a whole), has increased by at least 5 to 1 (preferably 10 to 1) over the normal resistance of the cells. The water absorbing gas may be air ( ) or nitrogen ( ); it may be at ambient temperature or heated ( ).

Performance recovery process for PEM fuel cells

A vehicle ( ) includes a fuel cell stack ( ) started when the stack is below freezing, by connection ( ) to the vehicle propulsion system ( ) within a few seconds of starting the flow of fuel ( ) and oxidant ( ), or when open circuit voltage ( ) is detected. The fuel is in excess of stochiometry requirement and the oxidant is in excess of at least twice stochiometric requirement, either may be at about atmospheric pressure or at 4 kPa (0.6 psi) or more above the pressure of any water in said water passages, and either may be below freezing. Water transport plates ( ) have water passages connected to a water circulation loop ( ) including a reservoir ( ) having an auxiliary heater ( ) connected ( ) to the stack. Warming of cell stack materials and ice in the water transport plates, heat of fusion of melting ice, warming of melted water, and evaporative cooling of water melted in the water transport plates keep the fuel cell cool until liquid coolant can be circulated.

Growing community of inventors

South Windsor, CT, United States of America

Gennady Resnick