German-US collaboration demonstrates strong power density results with HEM fuel cell
09 August 2013
A German-US collaboration including OH-Energy Germany, GmbH; the University of Delaware; Fraunhofer ICT; and Leibniz Institute for Polymer Research released initial results demonstrating 616 mW/cm2 peak power density at 80 °C for a hydroxide (OH-) exchange membrane (HEM) fuel cell. (Earlier post.)
The results are an early indication the partnership is on track to reach its stated goal of delivering 600 mW/cm2 from a platinum-free fuel cell by 2015. The US Department of Energy (DOE) has a technical target for proton exchange membrane (PEM) MEAs (membrane electrode assembly) of 1,000 mW/cm2 by 2020.
To date the collaboration—the primary focus of which is to bring platinum-free fuel cells to the transportation and power generation markets—has been coordinated by OH Energy, Inc. and SET Technology. The partnership hopes to decrease the cost of fuel cells by up to 75%.
Our encouraging initial fuel cell results and our experience with non-platinum catalysts allow us to predict with good accuracy that our efforts will lead to a 600 mW/cm2 peak power density without the use of platinum.
— Professor Yushan Yan of the University of Delaware
Professor Yan of UD studies thin ion-conducting polymer films called hydroxide exchange membranes (HEMs). In a hydroxide exchange membrane fuel cell, the membrane conducts hydroxide ions instead of hydrogen ions as in a PEM. Hydroxide exchange membranes fuel cells (HEMFCs) have the potential to solve the catalyst cost and durability problems of proton exchange membrane fuel cells (PEMFCs) while achieving high power and energy density.
By switching fuel cell electrochemical reactions from an acidic medium to a basic one and utilizing a highly conductive hydroxide exchange membrane (HEM), high-performance hydroxide exchange membrane fuel cells (HEMFCs) are innovative and radically different from the proton exchange membrane fuel cells (PEMFCs) that have been intensively researched and developed in the past two decades.
HEMFCs have ability to solve some of the most significant commercialization barriers of PEMFCs, including catalysts cost and durability, while at the same time achieving PEMFCs’ high power and energy density.
The most attractive feature of HEM fuel cells is that they are compatible with commonly available catalysts such as silver and nickel, so that mass production would not tax the world’s limited (and costly) reserves of precious metals such as platinum. Yan’s technology was recognized by the US Department of Energy's Advanced Research Projects Agency (ARPA-E) as one of 37 funded projects in ARPA-E’s first open call for projects in 2009.
OH Energy Germany is a wholly owned subsidiary of OH Energy, Inc. (USA). OH Energy, Inc. designs, develops and manufactures platinum-free membranes and fuel cells based on technology invented in Dr. Yan’s labs located at the University of California Riverside and the University of Delaware.
Hmm, that's 616w/litre.
For comparison, the Nissan stack:
'The new fuel cell stack has a power output of 85 kW from a unit that weighs 43kg and has a volume of 34 liters.'
http://integrityexports.com/2011/10/14/nissan-fuel-cell-stack-gets-world-beating-power-density/2011/
That's 2,500w/litre.
This may be good for stationary applications, but unless I have dropped a decimal place sounds limited at present for cars.
Posted by: Davemart | 09 August 2013 at 02:46 AM
"limited at present for cars"
No kidding! Try using an ICE. They work very well in the US.
Posted by: Kit P | 09 August 2013 at 05:36 AM
Davemart: getting the units wrong and so not comparing like with like. They state a power per membrane area of 616 mW/cm2; your quoting power per stack volume. The relevant tables are 1 and 3 in the DOE target report mentioned above.
Posted by: DavidJ | 09 August 2013 at 06:57 AM
@DavidJ:
Thanks for the link.
I still don't understand.
In table 1 they give the present state of the art as 640W/L, with a 2020 target of 650W/L
That is still around 4 times less than the Nissan at 2,500W/L - at stack level
Posted by: Davemart | 09 August 2013 at 08:50 AM
A higher power density (than 650W/L) is desirable but not necessary for automotive applications in the DOE's prognosis. Other factors like cost reduction - and so platinum reduction - need to be achieved. The Nissan stack relies upon platinum, this one does not so is a better bet for achieving all the DOE criteria.
Posted by: DavidJ | 10 August 2013 at 03:34 AM
DavidJ:
Many thanks.
Posted by: Davemart | 10 August 2013 at 10:19 AM
I should point out though that according to Nissan their stack greatly reduces platinum use, and they say they are ready to go with fuel cell cars as soon as someone rolls out some infrastructure,
Posted by: Davemart | 10 August 2013 at 10:21 AM