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Topic: Proton exchange membrane

	United States Patent Application: 0040096718
		A proton exchange membrane fuel cell including an anode and a cathode separated by a proton exchange membrane characterised by the proton exchange member comprising a semiconductor adapted to allow transfer of electrons from the cathode electrode to the anode electrode and protons from the anode electrode to the cathode electrode.
		As in proton membrane fuel cells, the solid electrolyte may be homogenous or constructed in segments connected to each other, one segment allowing the movement of the oxygen ion and the adjacent segment allowing the movement of electrons in one direction only.
		Proton exchange non-conductor membrane segment 6 allows the hydrogen proton to travel from the anode to the cathode while semiconductor membrane segment 8 allows the electrons to travel from the cathode to the anode.
	appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1='20040036394'&OS=&RS= (5829 words)

	Proton exchange membrane (PEM) fuel cells
		PEM fuel cells were mainly developed by General Electric (GE) in the period between 1959 and 1982.
		The electrolyte in a PEM fuel cell consists of a membrane of solid polymer which allows protons to be transferred from one side to the other.
		One disadvantage with the PEM fuel cell, however, is the use of platinum as a catalyst, but the amount of platinum has been dramatically reduced in recent years (see figure), and there seems to be great potential to reduce it even more.
	www.bellona.no /en/energy/hydrogen/report_6-2002/22984.html (506 words)

	Fuel Cell Today - Opening doors to fuel cells commercialisation
		A composite membrane for use in a fuel cell membrane electrode assembly comprises a porous polymeric substrate and an impregnant partially filling the substrate such that the substrate comprises a first region having pores substantially filled with the impregnant, and a second substantially porous region.
		A hydrogen-containing gas suitable for use in a fuel cell, especially in a proton exchange membrane fuel cell, is produced from a digestion gas yielded in methane fermentation of organic matter, and is then supplied to the fuel cell to generate electricity.
		PEM fuel cell performance losses caused during normal operation are recovered by periodically reducing the cathode potential to about 0.6 volts or less, and preferably to 0.1V or less.
	www.fuelcelltoday.com /PatentListings/PatentListingsExternal/PatentCategory/0,1703,Cat=&Itm=3,00.html (8257 words)

	Collecting the History of Proton Exchange Membrane Fuel Cells
		Proton exchange membrane (PEM) fuel cells work with a polymer electrolyte in the form of a thin, permeable sheet.
		PEM technology was invented at General Electric in the early 1960s, through the work of Thomas Grubb and Leonard Niedrach.
		PEM cells have also supplied power to unmanned blimps called aerostats and to sonobuoys, which are nautical buoys that generate and receive sonar signals.
	americanhistory.si.edu /fuelcells/pem/pemmain.htm (987 words)

	Fuel Cell Research and Development at UConn
		In a direct methanol fuel cell, methanol diffuses across the proton exchange membrane, depolarizes the cathode and lowers the performance of the fuel cell.
		Investigations are underway to develop high temperature proton exchange membranes in a Department of Energy sponsored project through a sub-contract from Energy Research Corporation, CT. Raising the operating temperature will enhance the electrode reactions and also reduce methanol crossover due to lower solubility of methanol vapor than liquid methanol.
		The study of PEM fuel cells under the affect of carbon monoxide fed to the anode, the work involves investigating the role of temperature, oxygen partial pressure, and relative humidity in reducing the CO polarization.
	www.engr.uconn.edu /~russkunz/ufrc/resfocus.html (1124 words)

	Lynntech Products: PEM Fuel Cells (Site not responding. Last check: 2007-10-16)
		A proton exchange membrane (PEM) fuel cell is a device capable of generating electricity directly by means of two electrochemical reactions which take place at the proton exchange membrane/catalyst interface at low temperatures (<80° C).
		PEM fuel cells can also be configured to directly consume methanol, such as the direct methanol fuel cell (DMFC).
		A PEM fuel cell is capable of using oxygen directly from air, or purified.
	www.lynntech.com /licensing/pem_fuelcell/index.shtml (347 words)

	Membranes and Membrane Electrode Assemblies for PEM Fuel Cells
		The study identifies the opportunities and technological requirements of the proton exchange membrane fuel cell and the MEA and the bipolar plates for the PEM fuel cell.
		The proton exchange membrane fuel cell is emerging as a winner in many of the primary categories that fuel cells can satisfy.
		Proton exchange membrane fuel cell development and commercialization is an ever-changing process.
	www.electronics.ca /reports/technology/membranes.html (1922 words)

	RC-235 Membrane and Membrane Electrode Assemblies for PEM Fuel Cells (Site not responding. Last check: 2007-10-16)
		Ion selective membranes used in PEM fuel cells are a part of the overall group of materials performing a variety of functions.
		The membranes to be developed for the PEM fuel cells are not the province of electrochemists, but the developmental arena of synthetic polymer chemists, chemical engineers, and membranologists.
		The membrane itself is at the center of the PEM fuel cell.
	www.bccresearch.com /editors/RC-235.html (751 words)

	Effect of Liquid Water Injection on PEM Fuel Cell Performance With Air and Oxygen as Cathode Reactants Using Different ... (Site not responding. Last check: 2007-10-16)
		However, before the PEM fuel cell system can become economically competitive with existing technologies and be applied in wide-range practical situations, its power density must be increased by a factor of six and its costs reduced by a factor of 10 [1].
		Prior efforts in sputtering the catalyst onto the surface of the electrode that is later hot pressed onto the membrane and mixing the catalyst-substrate with the membrane ionomer have resulted in significant improvement in the fuel cell performance and reduction in catalyst loading.
		First, by creating a 3D surface on the membrane deeper penetration and higher contact area between the membrane and the catalyst substrate will be achieved during hot pressing of the membrane onto the electrode.
	www.vacets.org /vtic97/tvnguyen.htm (1949 words)

	Types - Proton Exchange Membrane Fuel Cells
		Proton Exchange Membrane Fuel Cells (PEMFC) are believed to be the best type of fuel cell as the vehicular power source to eventually replace the gasoline and diesel internal combustion engines.
		PEM fuel cells use a solid polymer membrane (a thin plastic film) as the electrolyte.
		This polymer is permeable to protons when it is saturated with water, but it does not conduct electrons.
	www.fctec.com /fctec_types_pem.asp (390 words)

	ReliOn: About Fuel Cells (Site not responding. Last check: 2007-10-16)
		The hydrogen proton travels through the membrane, while the electron enters an electrical circuit, creating a DC electrical current.
		On the other side of the membrane, the proton and electron are recombined and mixed with oxygen from room air, forming pure water.
		By combining the generating power of multiple PEM cartridges, our fuel cells can be built to meet specific loads from 500 Watts to 5 kilowatts.
	www.avistalabs.com /fuelcells.asp (123 words)

	Proton Exchange Membrane Fuel Cell (PEMFC) - NFCRC Tutorial
		This type of fuel cell also known as the Polymer Electrolyte Membrane Fuel Cell consists of a proton conducting membrane, such as a perfluorosulphonic acid polymer as the electrolyte which has good proton conducting properties, contained between two Pt impregnated porous electrodes.
		The protons solvate with water molecules and diffuse through the membrane to the cathode to react with the O2 while picking up electrons and forming water.
		It is necessary to maintain a high enough water content in the electrolyte to avoid membrane dehydration and maintain proper ion conductivity without flooding the electrodes.
	www.nfcrc.uci.edu /EnergyTutorial/pemfc.html (467 words)

	DoD Fuel Cell - Fuel Cell Descriptions
		The Proton Exchange Membrane Fuel Cell (PEFC) offers an order of magnitude higher power density than any other fuel cell system, with the exception of the advanced aerospace AFC, which has comparable performance.
		This membrane is an electronic insulator, but an excellent conductor of hydrogen ions.
		The acid molecules are fixed to the polymer and cannot "leak" out, but the protons on these acid groups are free to migrate through the membrane.
	dodfuelcell.cecer.army.mil /proton.html (1325 words)

	Trends in Plastics - Proton Exchange Membrane (PEM) fuel cells
		Bipolar plates separate neighbouring cells and serve as the anode for one fuel cell and the cathode for the adjacent one.
		The protons penetrate the membrane and combine with oxygen to produce water and heat.
		Plastic membrane is not the only involvement of plastic in PEM fuel cell.
	www.plasticstrends.net /articles/pem.htm (640 words)

	Proton exchange membrane fuel cell power system (US6030718) (Site not responding. Last check: 2007-10-16)
		The proton exchange membrane fuel cell power system also includes an enclosure mounting a plurality of subracks which receive the discrete fuel cell modules.
		Additionally, a control system is disclosed which optimizes the performance parameters of the discrete proton exchange membrane fuel cell modules.
		a plurality of discrete proton exchange membrane fuel cell modules which are self-humidifying and which produce heat energy, and wherein each of the discrete fuel cell modules has a cathode air flow, and a preponderance of the heat energy is removed from the discrete proton exchange membrane fuel cell modules by the cathode air flow.
	www.delphion.com /details?pn=US06030718__ (925 words)

	Fuel Cells 2000 : Fuel Cell Basics : Types
		According to DOE, "they are the primary candidates for light-duty vehicles, for buildings, and potentially for much smaller applications such as replacements for rechargeable batteries." The proton exchange membrane is a thin plastic sheet that allows hydrogen ions to pass through it.
		The membrane is coated on both sides with highly dispersed metal alloy particles (mostly platinum) that are active catalysts.
		These cells are similar to the PEM cells in that they both use a polymer membrane as the electrolyte.
	www.fuelcells.org /basics/types.html (1768 words)

	Proton Exchange Membrane Fuel Cell Development with Lightweight Component Materials. Phase 1 - Storming Media
		Proton Exchange Membrane Fuel Cell Development with Lightweight Component Materials.
		Abstract: Although the Proton Exchange Membrane (PEM) fuel cell is a leading candidate for an automobile power source through meeting the zero emission requirement, its power density is currently an order of magnitude below the 400 W/kg criterion proposed by the Department of Energy.
		The emphasis was on atmospheric pressure and internally humidified cell operation as a potential means of system simplification and reduction of PEM fuel cell ancillary equipment complexity and weight.
	www.stormingmedia.us /57/5707/A570792.html (452 words)

	Fuel Cells 2000 : Information Resources : Fuel Cell Library
		China At the Crossroads: Energy, Transportation and the 21st Century - Report describes the implications of the vast explosion in vehicle growth in China, and argues "that the time is ripe for China to choose alternatives to petroleum-based transportation fuels and the vehicles that burn them".
		Discussion of and charts/diagrams on polymer electrolyte fuel cells, catalysts, membranes, electrode assemblies, components for gas distribution and current collection.
		Proton exchange membrane fuel cells have become the dominant fuel cell technology in the vehicle market, with 2000 sales of $104 million.
	www.fuelcells.org /info/fclib.html (11638 words)

	the Proton Exchange Membrane Fuel Cell (Site not responding. Last check: 2007-10-16)
		The PEMFC uses a polymer membrane as an electrolyte.
		The polymer is capable of conducting positive hydrogen ions: protons.
		The combination of electrodes and polymer membrane electrolyte is usually referred to as MEA (Membrane Electrode Assembly).
	www.ecn.nl /bct/fuelcellinfo/pemfc.en.html (244 words)

	PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL (CONTINUED) - MEMBRANES AND MEMBRANE ELECTRODE ASSEMBLIES FOR PEM FUEL - ...
		Polymer membranes are the heart of the proton exchange membrane (PEM) fuel cell, serving as the electrolyte.
		The PEM fuel cell uses an electrochemical process and operates as long as fuel is fed to it.
		A sub-set of the hydrogen fed PEM fuel cell is the direct alcohol feed fuel cell.
	bcc.ecnext.com /coms2/summary_0279-15801_ITM (2093 words)

	EyeforFuelCells - Facilitating the commercialisation of Fuel Cell technology (Site not responding. Last check: 2007-10-16)
		The membrane is made from polybenzimidazole (pbi), a polymer now used in firefighters' protective garments because it can withstand high heat.
		These novel membranes are said to generate electric current more easily, operate across a broader temperature range, and cost less than the incumbent materials, which are mainly sulfonated fluoropolymers.
		Since the 1960s, Nafion has been the membrane of choice in specialized fuel-cell applications such as spacecraft, although Japan's Asahi Chemical and others have more recently imported comparable membranes into the U.S. Now, a mass market for PEM fuel cells is emerging, sparking interest in lower-cost membranes.
	www.eyeforfuelcells.com /ReportDisplay.asp?ReportID=1573 (333 words)

	BMW World - PEM Fuel Cell
		History of Proton Exchange Membrane Fuel Cells from the Smithsonian.
		The Proton Exchange Membrane Fuel Cell has technical information about a polymer electrolyte membrane (PEM) fuel cell.
		Ballard Power Systems is recognized as a world leader in developing, manufacturing and marketing zero-emission proton exchange.
	www.bmwworld.com /hydrogen/pem_fuel_cell.htm (225 words)

	Vision Engineer - Proton Exchange Membrane Fuel Cell (Site not responding. Last check: 2007-10-16)
		Also known as Polymer Electrolyte Membrane Fuel Cell, this low temperature fuel cell is mainly used in vehicle applications.
		The electrolyte in this fuel cell is an ion exchange membrane which is a good proton conductor.
		Water management in the membrane is crucial for efficient performance: The fuel cell must operate under conditions where the by-product water does not evaporate faster than it is produced because the membrane must be hydrated.
	www.visionengineer.com /env/pem.shtml (187 words)

	New High-Temperature Membranes Developed for Proton Exchange Membrane Fuel Cells
		The most widely used membrane materials for proton exchange membrane (PEM) fuel cells are based on sulfonated perfluorinated polyethers, typically Nafion 117, Flemion, or Aciplex.
		Increasing the operating temperature of PEM fuel cells from 80 to 120 °C would significantly increase their power densities and enhance their durability by reducing the susceptibility of the electrode catalysts to carbon monoxide poisoning.
		A new series of organically modified siloxane (ORMOSIL) polymers were synthesized for use as membrane materials in a high-temperature PEM fuel cell (see the preceding figure).
	www.lerc.nasa.gov /WWW/RT/2003/5000/5150kinder.html (434 words)

	SERC: Fuel Cells
		A PEM (Proton Exchange Membrane, also called Polymer Electrolyte Membrane) fuel cell uses a simple chemical reaction to combine hydrogen and oxygen into water, producing electric current in the process.
		The proton exchange membrane allows protons to flow through, but not electrons.
		As a result, the hydrogen ions flow directly through the proton exchange membrane to the cathode, while the electrons flow through an external circuit.
	www.humboldt.edu /~serc/fc.html (246 words)

	Proton Energy Systems (Site not responding. Last check: 2007-10-16)
		Proton Energy Systems Inc. is a Distributed Energy Systems Corp company.
		Hydrogen is the most abundant element in the universe, and may also be the ultimate energy carrier, offering the promise of zero pollution energy production at the point of use.
		Proton Energy Systems Inc. manufactures PEM (Proton Exchange Membrane) electrochemical systems to make hydrogen from water in a zero pollution process, which allows for safe, pure, reliable on-site hydrogen, to meet today’s commercial hydrogen requirements worldwide.
	www.protonenergy.com (255 words)

	A New Composite Proton Exchange Membrane (Site not responding. Last check: 2007-10-16)
		Because they produce clean power and have no moving parts, proton exchange membrane (PEM) fuel cells have great potential as a source for clean, renewable power.
		However, one of the current limitations of fuel cell technology is the requirement that the PEMs maintain a high level of hydration.
		The membrane will have an advantage over more familiar all-polymer membranes because of its innate ability to operate in a water-free atmosphere.
	www.er.doe.gov /sbir/awards_abstracts/sbirsttr/cycle21/phase1/089.htm (169 words)

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