Team in Japan develops durable, high-temperature PEM fuel cell
03 May 2013
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| Power density curves of the PVPA-doped MEA measured at 25°C (orange line), 40°C (pink line), 60°C (blue line), 80°C (green line), 100°C (purple line) and 120°C (red line). Berber et al. Click to enlarge. |
Researchers in Japan have developed a novel polymer electrolyte membrane fuel cell (PEFC) that shows high durability (>400,000 cycles) together with high power density (252 mW/cm2) at high temperatures of 120°C under a non-humidified condition.
In a paper published in Scientific Reports, the open access journal of the Nature Publishing Group, they suggest that the study “opens the door” for the next-generation high temperature and non-humidified PEFC for use in the “real world”.
Higher-temperature PEM fuel cells are of interest due to a number of performance and cost advantages, including higher power efficiency; elimination of the cooling device and water management system; reduction of CO poisoning of the platinum (Pt) and/or enabling the use of a non-precious metal catalyst. Volkswagen, as an example, in 2006 reported developing a PEM (proton exchange membrane) fuel cell that operates at temperatures of about 120 °C. (Earlier post.)
In the current PEFC systems, water-assisted proton conduction in the conventional polyelectrolytes limit the operation temperature below 100 °C. The limitation of operating temperature originated from the poor proton conductivity of the conventional polyelectrolytes such as Nafion at temperatures above 100 °C, thus the development of a new polyelectrolyte with a high proton conductivity at high temperature has been strongly desired. To overcome this temperature limitation problem, the use of polymer membrane doped with a non-volatile liquid acid as a polymer electrolyte membrane (PEM) has been proposed, in which the mobile acid such as phosphoric acid (PA) is responsible for the proton conduction through the vehicle mechanism....However, recent studies have revealed that leaching of liquid PA...causes inhomogeneous PA distribution that results in deterioration of PEFC performance during long-term operation.
In this study, in order to prevent acid leaching from the high temperature PEFC system, we used poly(vinylphosphonic acid) (PVPA) in place of PA because PVPA is a polymeric acid and is stably bound to the PBIs via multipoint acid-base reactions.
—Berber et al.
The researchers used a membrane electrode assembly (MEA) with Pt on poly(vinylphosphonic acid)-doped polybenzimidazole wrapped on carbon nanotube and poly(vinylphosphonic acid)-doped polybenzimidazole for the electrocatalyst and electrolyte membrane, respectively.
Among their findings was that the power density of the MEA increased when increasing the measurement temperature up to 120°C—a result in good agreement with the increase of the proton conductivity at higher temperatures. As a result, they said, they expect a higher power density above 120°C. This study is underway now by using a new apparatus capable of 120–200 °C measurements.
Resources
Mohamed R. Berber, Tsuyohiko Fujigaya, Kazunari Sasaki & Naotoshi Nakashima (2013) Remarkably Durable High Temperature Polymer Electrolyte Fuel Cell Based on Poly(vinylphosphonic acid)-doped Polybenzimidazole. Sci. Rep. doi: 10.1038/srep01764
HT fuel cells are also very suitable for use as a range extender as they have very low balance of plant:
http://www.fuelcellmarkets.com/content/images/articles/091217%20General%20EnerFuel%20Presentation%20For%20Website.pdf
In the link it is also mentioned that low susceptibility to poisoning means that on-board reforming may be possible.
That would nearly eliminate the issue of infrastructure, as natural gas and possibly other fuels could be used.
Posted by: Davemart | 03 May 2013 at 01:43 PM
It you could reform methanol on board, it would be really good.
The mistake may be to focus on H2, which is a very tricky fuel. If you focus on methanol (biomethanol ?) you have a liquid fuel which is much easier to handle.
Posted by: mahonj | 03 May 2013 at 01:51 PM
Volvo is working on a C30 with HTPEM that not only reforms methanol, but other hydrocarbons like gasoline and diesel.
Posted by: SJC | 03 May 2013 at 02:20 PM
Not only methanol but anhydrous ammonia (carbon-free).
Posted by: Engineer-Poet | 04 May 2013 at 06:01 AM
Or DME, presumably.
Posted by: Davemart | 04 May 2013 at 09:21 AM
FCEVs may not be dead yet and may become a serious competitor if flex fuel affordable units can be mass produced.
Posted by: HarveyD | 04 May 2013 at 09:59 AM
https://www.greentechmedia.com/articles/read/Fuel-Cells-2013-Bloom-Energys-Reality-Distortion-Field fc cost?
Posted by: kelly | 04 May 2013 at 04:46 PM
DME is not a room-temperature liquid, and loses quite a bit of energy in the dehydration. Methanol is preferable.
Posted by: Engineer-Poet | 05 May 2013 at 03:35 AM
Well we know the cars are coming as the larger scale factories to build the stacks are in last stage of prep for limited mass production runs. Gona be a lot of different designs in the first gen of cars.
The high temp designs supposedly offer a lot of cost and durability perks as well as a large boost in fuel eff. But for the life of me I have no idea what if any of the cars coming out this side of 2016 use high temp fuel cells. I know one of them WAS but they havnt said anything recently so I have no clue who they were or if they even still exist...
Posted by: wintermane2000 | 05 May 2013 at 05:18 AM
The world is not ready for this technology.
Posted by: A D | 05 May 2013 at 05:36 AM
"anhydrous ammonia"
Could you think of a more toxic fuel? The control system engineer should stick to commenting on control systems.
Thousands of farmer and other workers are hospitalized every year handling ammonia.
Fool cells like BEV are DOA in the market place. Incredible bad engineer idea promoted by politicians who never ever did any real work.
Posted by: Kit P | 08 May 2013 at 05:45 AM
How about methyl mercury? Some rocket scientists actually did consider it a few decades back; read "Ignition!".
Anhydrous ammonia has drawbacks, but as a carrier for hydrogen which is dense and handled relatively easily, it appears to have few peers. If we had to, we could find ways to use it in cars with acceptable risks. I don't think we have to, and I doubt we will, but if you can't think outside the box you are going to miss lots of important stuff.
Posted by: Engineer-Poet | 08 May 2013 at 02:06 PM
Using the most common liquid fuels such as diesel, gasoline, ethanol, LNG etc could make an FCEV more acceptable and practical?
Depending on e-storage unit size, liquid fuel consumption (and imports) could be reduced.
Posted by: HarveyD | 10 May 2013 at 10:44 AM
When it comes to anhydrous ammonia what does thinking inside the box gets us. Anhydrous ammonia is a synthetic chemical generally produced with natural gas as the hydrogen carrier for the Haber Bosch process.
LNG is a common non-toxic transportation fuel.
Natural gas can also be used to make synthetic diesel fuel.
Posted by: Kit P | 10 May 2013 at 05:41 PM
The Stranded Wind project proposes to make ammonia directly from nitrogen gas and water, by electrolysis using wind power in excess of immediate grid demand. IIRC, they have proposed motor fuel as one of the uses of their product. I am doubtful about the economics but technically their proposal would work.
Posted by: Engineer-Poet | 11 May 2013 at 07:52 PM
"I am doubtful about the economics ..."
Really! E-P brings up stuff that are terrible ideas from a safety standpoint then he admits it is not economical. Sarcasm is appropriate.
Posted by: Kit P | 12 May 2013 at 07:14 AM
Yes, all of those tanks full of NH3 being shipped down the roads and pulled across farmers' fields are terrible ideas from a safety standpoint (if you're Kit P and hate farming and farmers).
Posted by: Engineer-Poet | 13 May 2013 at 06:01 AM