Fuel cell membrane patented by Sandia outperforms market

September 07, 2016

ALBUQUERQUE, N.M. -- Fuel cells provide power without pollutants. But, as in the Goldilocks story, membranes in automobile fuel cells work at temperatures either too hot or too cold to be maximally effective. A polyphenyline membrane patented by Sandia National Laboratories, though, seems to work just about right, says Sandia chemist Cy Fujimoto.

The membrane, which operates over a wide temperature range, lasts three times longer than comparable commercial products, Fujimoto and his co-authors say in the Aug. 21 issue of Nature Energy.

Fuel-cell PEMs (proton-exchange membranes) allow the excretion of protons -- the husk, in a sense -- of the material providing the electrons that form the fuel cell's electrical output. If the protons can't pass easily within the cell, the fettered flow reduces the electrical output.

Currently commercial PEMs in most fuel-cell-powered vehicles require water, so their operating temperature can't get higher than water's boiling point. Higher temperatures dry out the membrane, increase cell resistance and reduce performance, said Fujimoto.

"Part of the issues with the current PEMs is that you need to hydrate the hydrogen fuel stream for high performance, and the fuel cell can't run effectively at temperatures higher than the boiling point of water," he said.

"This problem can be solved by employing hydrated fuel streams and having a larger radiator to more effectively dissipate waste heat," Fujimoto continued. "Automakers are doing this now. But if PEM fuel cells didn't need water to run, it would make things a lot simpler."

Another problem is that material costs for the current membrane of choice can be approximately $250-$500 per square meter. "The DOE [Department of Energy] would like to see $5 to $20 a square meter," Fujimoto said.

Researchers have tried to solve these problems with a high-temperature method that uses phosphoric acid to dope a polybenzimidazole membrane at more than 350 degrees Fahrenheit. But the membrane can't operate below 284 degrees without degrading the phosphoric acid. Thus the membrane is unsuitable for automotive applications, where water condensation from cold engine start-ups and other normal reactions at the fuel cell cathode unavoidably bring the temperature down into undesirable ranges that leach the phosphoric acid out of the reaction.

Now comes the first ammonium ion-pair fuel cell -- created at Los Alamos National Laboratory -- to combine phosphates with the Sandia-patented membrane. The ammonium-biphosphate ion pairs have exhibited stable performance over a wide range of temperatures from 176-320 degrees F, responded well to changes in humidity and lasted three times longer than most commercial PEM fuel cell membranes.

"There probably will be industrial interest in this discovery," Fujimoto said. "Our polymer contains a tethered positive charge which interacts more strongly with phosphoric acid, which improves acid retention. Heating the fuel cell and adding humidity doesn't reduce performance."
-end-
The fuel cell work was supported by the Fuel Cell Technology Office of the Department of Energy's Office of Energy Efficiency and Renewable Energy.

Sandia National Laboratories is a multimission laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy's National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.

DOE/Sandia National Laboratories

Related Fuel Cell Articles from Brightsurf:

INRS researchers develop a new membraneless fuel cell
The research team of INRS (Institut national de la recherche scientifique) professor Mohamed Mohamedi has designed a green membraneless fuel cell that uses oxygen from the air.

Researchers advance fuel cell technology
Washington State University researchers have made a key advance in solid oxide fuel cells (SOFCs) that could make the highly energy-efficient and low-polluting technology a more viable alternative to gasoline combustion engines for powering cars.

Niobium used as catalyst in fuel cell
Glycerol fuel cell can replace batteries in cell phones and laptops, and could be used in future to run electric cars and supply power to homes.

Inside the fuel cell -- Imaging method promises industrial insight
Hydrogen-containing substances are important for many industries, but scientists have struggled to obtain detailed images to understand the element's behavior.

Selenium anchors could improve durability of platinum fuel cell catalysts
Researchers at the Georgia Institute of Technology have developed a new platinum-based catalytic system that is far more durable than traditional commercial systems and has a potentially longer lifespan.

Activity of fuel cell catalysts doubled
An interdisciplinary research team at the Technical University of Munich (TUM) has built platinum nanoparticles for catalysis in fuel cells: The new size-optimized catalysts are twice as good as the best process commercially available today.

More flexible nanomaterials can make fuel cell cars cheaper
A new method of increasing the reactivity of ultrathin nanosheets, just a few atoms thick, can someday make fuel cells for hydrogen cars cheaper, finds a new Johns Hopkins study.

Developed self-controlling 'smart' fuel cell electrode material
A research team led by Professor Kang Taek Lee in the Department of Energy Science and Engineering developed electrode material for a new form of high-performance solid oxide fuel cell.

Finally, a robust fuel cell that runs on methane at practical temperatures
Either exorbitantly expensive fuel or insanely hot temperatures have made fuel cells a boutique proposition, but now there's one that runs on cheap methane and at much lower temperatures.

New fuel cell concept brings biological design to better electricity generation
Fuel cells have long been viewed as a promising power source.

Read More: Fuel Cell News and Fuel Cell Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.