 |
|
Chemical Could Revolutionize Polymer Fuel Cells
August 25, 2005Heat has always been a problem for fuel cells. There's usually either too much (ceramic fuel cells) for certain portable uses, such as automobiles or electronics, or too little (polymer fuel cells) to be efficient.
Fuel cell with triazole
While polymer electrolyte membrane (PEM) fuel cells are widely considered the most promising fuel cells for portable use, their low operating temperature and consequent low efficiency have blocked their jump from promising technology to practical technology.
But researchers at the Georgia Institute of Technology have pinpointed a chemical that could allow PEM fuel cells to operate at a much higher temperature without moisture, potentially meaning that polymer fuel cells could be made much more cheaply than ever before and finally run at temperatures high enough to make them practical for use in cars and small electronics.
A team lead by Dr. Meilin Liu, a professor in the School of Materials Science and Engineering at Georgia Tech, has discovered that a chemical called triazole is significantly more effective than similar chemicals researchers have explored to increase conductivity and reduce moisture dependence in polymer membranes. The findings were published in the Journal of the American Chemical Society.
"Triazole will greatly reduce many of the problems that have prevented polymer fuel cells from making their way into things like cars, cell phones and laptops," said Liu. "It's going to have a dramatic effect."
A fuel cell essentially produces electricity by converting the chemicals hydrogen and oxygen into water. To do this, the fuel cell needs a proton exchange membrane, a specially treated material that looks a lot like plastic wrap, to conduct protons (positively charged ions) but block electrons. This membrane is the key to building a better fuel cell.
Current PEMs used in fuel cells have several problems that prevent them from wide use. First, their operating temperature is so low that even trace amounts of carbon monoxide in hydrogen fuel will poison the fuel cell's platinum catalyst. To avoid this contamination, the hydrogen fuel must go through a very expensive purification process that makes fuel cells a pricey alternative to conventional batteries or gasoline-fueled engines. At higher temperatures, like those allowed by a membrane containing triazole, the fuel cell can tolerate much higher levels of carbon monoxide in the hydrogen fuel.
The use of triazole also solves one of the most persistent problems of fuel cells - heat. Ceramic fuel cells currently on the market run at a very high temperature (about 800 degrees Celsius) and are too hot for most portable applications such as small electronics.
While existing PEM fuel cells can operate at much lower temperatures, they are much less efficient than ceramic fuel cells. Polymer fuel cell membranes must be kept relatively cool so that membranes can retain the moisture they need to conduct protons. To do this, polymer fuel cells were previously forced to operate at temperatures below 100 degrees Celsius.
Heat must be removed from the fuel cells to keep them cool, and a water balance has to be maintained to ensure the required hydration of the PEMs. This increases the complexity of the fuel cell system and significantly reduces its overall efficiency. But by using triazole-containing PEMs, Liu's team has been able to increase their PEM fuel cell operating temperatures to above 120 degrees Celsius, eliminating the need for a water management system and dramatically simplifying the cooling system.
"We're using the triazole to replace water," Liu said. "By doing so, we can bring up the temperature significantly."
Triazole is also a very stable chemical and fosters stable fuel cell operating conditions.
While they have pushed their polymer fuel cells to 120 degrees Celsius with triazole, Liu's team is looking into better polymers to get those temperatures even higher, he said.
Georgia Institute of Technology
A team lead by Dr. Meilin Liu, a professor in the School of Materials Science and Engineering at Georgia Tech, has discovered that a chemical called triazole is significantly more effective than similar chemicals researchers have explored to increase conductivity and reduce moisture dependence in polymer membranes. The findings were published in the Journal of the American Chemical Society.
"Triazole will greatly reduce many of the problems that have prevented polymer fuel cells from making their way into things like cars, cell phones and laptops," said Liu. "It's going to have a dramatic effect."
A fuel cell essentially produces electricity by converting the chemicals hydrogen and oxygen into water. To do this, the fuel cell needs a proton exchange membrane, a specially treated material that looks a lot like plastic wrap, to conduct protons (positively charged ions) but block electrons. This membrane is the key to building a better fuel cell.
Current PEMs used in fuel cells have several problems that prevent them from wide use. First, their operating temperature is so low that even trace amounts of carbon monoxide in hydrogen fuel will poison the fuel cell's platinum catalyst. To avoid this contamination, the hydrogen fuel must go through a very expensive purification process that makes fuel cells a pricey alternative to conventional batteries or gasoline-fueled engines. At higher temperatures, like those allowed by a membrane containing triazole, the fuel cell can tolerate much higher levels of carbon monoxide in the hydrogen fuel.
The use of triazole also solves one of the most persistent problems of fuel cells - heat. Ceramic fuel cells currently on the market run at a very high temperature (about 800 degrees Celsius) and are too hot for most portable applications such as small electronics.
While existing PEM fuel cells can operate at much lower temperatures, they are much less efficient than ceramic fuel cells. Polymer fuel cell membranes must be kept relatively cool so that membranes can retain the moisture they need to conduct protons. To do this, polymer fuel cells were previously forced to operate at temperatures below 100 degrees Celsius.
Heat must be removed from the fuel cells to keep them cool, and a water balance has to be maintained to ensure the required hydration of the PEMs. This increases the complexity of the fuel cell system and significantly reduces its overall efficiency. But by using triazole-containing PEMs, Liu's team has been able to increase their PEM fuel cell operating temperatures to above 120 degrees Celsius, eliminating the need for a water management system and dramatically simplifying the cooling system.
"We're using the triazole to replace water," Liu said. "By doing so, we can bring up the temperature significantly."
Triazole is also a very stable chemical and fosters stable fuel cell operating conditions.
While they have pushed their polymer fuel cells to 120 degrees Celsius with triazole, Liu's team is looking into better polymers to get those temperatures even higher, he said.
Georgia Institute of Technology
Fuel Cells Current Events and Fuel Cells News RSSUD researchers show that plants can accumulate nanoparticles in tissues
Researchers at the University of Delaware have provided what is believed to be the first experimental evidence that plants can take up nanoparticles and accumulate them in their tissues.
When a good nanoparticle goes bad
Researchers at Cornell University recently made a major breakthrough when they invented a method to test and demonstrate a long-held hypothesis that some very, very small metal particles work much better than others in various chemical processes such as converting chemical energy to electricity in fuel cells or reducing automobile pollution.
Hydrogen tank lighter than battery
Dutch-sponsored researcher Robin Gremaud has shown that an alloy of the metals magnesium, titanium and nickel is excellent at absorbing hydrogen.
Secret Lives of Catalysts Revealed
The first-ever glimpse of nanoscale catalysts in action could lead to improved pollution control and fuel cell technologies. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory observed catalysts restructuring themselves in response to various gases swirling around them, like a chameleon changing its color to match its surroundings.
Metal-organic frameworks feel the pressure of Argonne scientists
Scientists at U.S. Department of Energy's Argonne National laboratory are putting the pressure on metal-organic frameworks (MOF).
New Carbon Material Shows Promise of Storing Large Quantities of Renewable Electrical Energy
Engineers and scientists at The University of Texas at Austin have achieved a breakthrough in the use of a one-atom thick structure called "graphene" as a new carbon-based material for storing electrical charge in ultracapacitor devices, perhaps paving the way for the massive installation of renewable energies such as wind and solar power.
Scientists peel away the mystery behind gold's catalytic prowess
Few materials have exercised as much of a hold on the human imagination, or on human history, as has gold.
Turning Waste Material into Ethanol
Say the word "biofuels" and most people think of grain ethanol and biodiesel. But there's another, older technology called gasification that's getting a new look from researchers at the U.S. Department of Energy's Ames Laboratory and Iowa State University. By combining gasification with high-tech nanoscale porous catalysts, they hope to create ethanol from a wide range of biomass, including distiller's grain left over from ethanol production, corn stover from the field, grass, wood pulp, animal waste, and garbage.
Building a better telecom system
Hurricane Katrina helped University of Texas professor, Alexis Kwasinski, formulate a new plan for the U.S. telecom system: a de-centralized power architecture that would have kept the lights and phones on in New Orleans.
Fuel from food waste: bacteria provide power
Researchers have combined the efforts of two kinds of bacteria to produce hydrogen in a bioreactor, with the product from one providing food for the other.
More Fuel Cells Current Events and Fuel Cells News Articles
 | Designing and Building Fuel Cells by Colleen Spiegel Acquire an All-in-One Toolkit for Expertly Designing, Modeling, and Constructing High-Performance Fuel Cells Designing and Building Fuel Cells equips you with a hands-on guide for the design, modeling, and construction of fuel cells that perform as well or better than some of the best fuel cells on the market today. Filled with over 120 illustrations and schematics of fuel cells and... |
 | Fuel Cell Projects for the Evil Genius by Gavin D J Harper FUEL YOUR EVIL URGES WHILE YOU BUILD GREEN ENERGY PROJECTS! Go green as you amass power! Fuel Cell Projects for the Evil Genius broadens your knowledge of this important, rapidly developing technology and shows you how to build practical, environmentally conscious projects using the three most popular and widely accessible fuel cells! In Fuel Cell Projects for the Evil Genius, high-tech... |
 | Fuel Cell Systems Explained (Second Edition) by James Larminie, Andrew Dicks Building on the success of the first edition Fuel Cell Systems Explained presents a balanced introduction to this growing area. "In summary, an altogether satisfying book that puts within its covers the academic tools necessary for explaining fuel cell systems on a multidisciplinary basis." Power Engineering Journal "An excellent book….well written and produced." Journal of Power... |
| Fuel Cell Fundamentals by Ryan O'Hayre, Whitney Colella, Suk-Won Cha, Fritz B. Prinz As the search for alternative fuels heats up, no topic is hotter than fuel cells. Filling a glaring gap in the literature, Fuel Cell Fundamentals, Second Edition gives advanced undergraduate and beginning level graduate students an important introduction to the basic science and engineering behind fuel cell technology. Emphasizing the foundational scientific principles that apply to any fuel cell... | |
 | Microbial Fuel Cells by Bruce E. Logan The theory, design, construction, and operation of microbial fuel cells Microbial fuel cells (MFCs), devices in which bacteria create electrical power by oxidizing simple compounds such as glucose or complex organic matter in wastewater, represent a new and promising approach for generating power. Not only do MFCs clean wastewater, but they also convert organics in these wastewaters into... |
 | 21st Century Complete Guide to Renewable Energy and Fuels, Advanced Vehicles, Solar Power, Hydrogen, Fuel Cells, Wind, Biomass, Tech Transfer (Four CD-ROM Set) by U.S. Government Newly revised and expanded with updated material for 2008, our unique electronic book compilation on four CD-ROMs has an amazing collection of the best federal documents and resources on renewable energy, with complete coverage of every aspect of the National Renewable Energy Laboratory (NREL), advanced vehicles and fuels, solar power, hydrogen energy and fuel cells, wind power, biomass,... |
 | PEM Fuel Cell Electrocatalysts and Catalyst Layers: Fundamentals and Applications Proton exchange membrane (PEM) fuel cells, including H2/O2 (air) and methanol/O2 (air) fuel cells, are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. PEM Fuel Cell Electrocatalysts... |
 | Fuel Cells: From Fundamentals to Applications by Supramaniam Srinivasan This is a concise source of the basic electrochemical principles and the engineering aspects involved in the development and commercialization of fuel cells. It provides a lucid description of the applications and techno-economic assessment of fuel cell technologies along with an in-depth discussion of conventional and novel approaches for generating energy. The first part covers the electrode... |
 | Control of Fuel Cell Power Systems: Principles, Modeling, Analysis and Feedback Design (Advances in Industrial Control) by Jay T. Pukrushpan, Anna G. Stefanopoulou, Huei Peng The problem of greenhouse gas (particularly carbon dioxide) release during power generation in fixed and mobile systems is widely acknowledged. Fuel cells are electrochemical devices offering clean and efficient energy production by the direct conversion of gaseous fuel into electricity. As such, they are under active study for commercial stationary power generation, residential applications and... |
 | Modern Electric, Hybrid Electric, and Fuel Cell Vehicles: Fundamentals, Theory, and Design (Power Electronics and Applications Series) by Mehrdad Ehsani, Yimin Gao, Sebastien E. Gay, Ali Emadi Air quality is deteriorating, the globe is warming, and petroleum resources are decreasing. The most promising solutions for the future involve the development of effective and efficient drive train technologies. This comprehensive volume meets this challenge and opportunity by integrating the wealth of disparate information found in scattered papers and research. Modern Electric, Hybrid... |
| © 2008 BrightSurf.com |