Methane-powered laptops may be closer than you think

Nov 17, 2010
Methane-powered laptops may be closer than you think
Top view, cathode side, of a free-standing Pt/YSZ/Pt fuel cell showing characteristic buckling patterns. The cell width is 160 microns. Photo courtesy of Shriram Ramanathan.

(PhysOrg.com) -- Making fuel cells practical and affordable will not happen overnight. It may, however, not take much longer.

With advances in nanostructured devices, lower operating temperatures, and the use of an abundant and cheaper materials, a group of researchers led by Shriram Ramanathan at the Harvard School of Engineering and Applied Sciences (SEAS) are increasingly optimistic about the commercial viability of the technology.

Ramanathan, an expert and innovator in the development of solid-oxide fuel cells (SOFCs), says they may, in fact, soon become the go-to technology for those on the go.

Electrochemical fuel cells have long been viewed as a potential eco-friendly alternative to fossil fuels—especially as most SOFCs leave behind little more than water as waste.

The obstacles to using SOFCs to charge laptops and phones or drive the next generation of cars and trucks have remained reliability, temperature, and cost.

Fuel cells operate by converting chemical energy (from hydrogen or a hydrocarbon fuel such as methane) into an electric current. Oxygen ions travel from the cathode through the electrolyte toward the anode, where they oxidize the fuel to produce a current of electrons back toward the cathode.

That may seem simple enough in principle, but until now, SOFCs have been more suited for the laboratory rather than the office or garage. In two studies appearing in the Journal of Power Sources this month, Ramanathan's team reported several critical advances in SOFC technology that may quicken their pace to market.

In the first paper, Ramanathan's group demonstrated stable and functional all-ceramic thin-film SOFCs that do not contain any platinum.

In thin-film SOFCs, the electrolyte is reduced to a hundredth or even a thousandth of its usual scale, using densely packed layers of special ceramic films, each just nanometers in thickness. These micro-SOFCs usually incorporate platinum electrodes, but they can be expensive and unreliable.

"If you use porous metal electrodes," explains Ramanathan, "they tend to be inherently unstable over long periods of time. They start to agglomerate and create open circuits in the fuel cells."

Ramanathan's platinum-free micro-SOFC eliminates this problem, resulting in a win-win: lower cost and higher reliability.

In a second paper published this month, the team demonstrated a methane-fueled micro-SOFC operating at less than 500° Celsius, a feat that is relatively rare in the field.

Traditional SOFCs have been operating at about 800–1000°C, but such high temperatures are only practical for stationary power generation. In short, using them to power up a smartphone mid-commute is not feasible.

In recent years, materials scientists have been working to reduce the required operating temperature to about 300–500°C, a range Ramanathan calls the "sweet spot."

Moreover, when fuel cells operate at lower temperatures, material reliability is less critical—allowing, for example, the use of less expensive ceramics and metallic interconnects—and the start-up time can be shorter.

"Low temperature is a holy grail in this field," says Ramanathan. "If you can realize high-performance solid-oxide fuel cells that operate in the 300–500°C range, you can use them in transportation vehicles and portable electronics, and with different types of fuels."

The use of methane, an abundant and cheap natural gas, in the team's SOFC was also of note. Until recently, hydrogen has been the primary fuel for SOFCs. Pure hydrogen, however, requires a greater amount of processing.

"It's expensive to make pure hydrogen," says Ramanathan, "and that severely limits the range of applications."

As methane begins to take over as the fuel of choice, the advances in temperature, reliability, and affordability should continue to reinforce each other.

"Future research at SEAS will explore new types of catalysts for SOFCs, with the goal of identifying affordable, earth-abundant materials that can help lower the operating temperature even further," adds Ramanathan.

research at SEAS is funded by the same NSF grant that enabled the "Robobees" project led by Robert J. Wood, Assistant Professor of Electrical Engineering. Wood and Ramanathan hope that micro-SOFCs will provide the tiny power source necessary to get the flying robots off the ground.

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User comments : 13

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Modernmystic
3.7 / 5 (3) Nov 17, 2010
No, they aren't...
Donutz
not rated yet Nov 17, 2010
Soooooo... if I eat chili, I can power my own laptop.

There's a Dilbert cartoon for this, involving Wally.
Ravenrant
not rated yet Nov 17, 2010
And I know exactly where to hook them up too.
JimB135
5 / 5 (2) Nov 17, 2010
No, they aren't...


Seems that way doesn't it.

Fusion power is always 20 years away. Fuel cells for our portable electronics have always been "just around the corner."

It would be cool to be able to pop a fuel cartridge into your laptop and have it run for a month.
drunken_lizard
not rated yet Nov 17, 2010
Fusion power is always 20 years away.


I've only ever heard that Fusion power is 50 years away commercially. But it depends on how you define "Fusion power"; are we talking about stable hydrogen plasma fusion with a positive EV, or are we talking about large scale civilian deployment? It's a grey area.
Javinator
3 / 5 (1) Nov 17, 2010
Soooooo... if I eat chili, I can power my own laptop.


It's closer than you think! Didn't you read the title?! ;)
otto1932
1 / 5 (17) Nov 17, 2010
PinkElephant
5 / 5 (1) Nov 17, 2010
WTF, otto? (I mean, relevance?)

Anyway,
Fuel cells for our portable electronics have always been "just around the corner."
You can buy them right now (though most *portable* ones won't power your laptop for a MONTH...) Here's a sample:

http://www.horizo...tore.htm
http://www.laptop...uel-cell
http://www.ultrac...products

(though the latter seems to be military-only, with no civilian sales...)
Newbeak
not rated yet Nov 17, 2010
WTF, otto? (I mean, relevance?)

Anyway,
Fuel cells for our portable electronics have always been "just around the corner."
You can buy them right now (though most *portable* ones won't power your laptop for a MONTH...) Here's a sample:

http://www.horizo...tore.htm

(though the latter seems to be military-only, with no civilian sales...)

Thanks for the links,PinkElephant. As soon as I saw this piece,I recalled seeing something about commercially available fuel cells somewhere.
otto1932
1 / 5 (14) Nov 18, 2010
WTF, otto? (I mean, relevance?)
:-)
-No, the picture just caught my eye, I know the moderators are following our rantings in the other thread and perhaps are having a little fun? Is that the ONLY pic they could have used?

Maybe we should demand buckling pattern restrictors so this type of graphic affront doesn't happen again-
PinkElephant
not rated yet Nov 18, 2010
Ah, I get it. Though this one's mirror-reflected. Not *exactly* the right configuration.

Still, it does say something about the state of your mind that this is the association you came up with. To me, it looked more like a starfish...
otto1932
1 / 5 (14) Nov 18, 2010
A fascist starfish...
Many swastikoidal shapes to be seen in the corporate sphere:
https://www.oppen...ndex.jsp
https://www.bankofamerica.com/
http://www.grantt...=default
http://www.itt.com/
https://chaseonline.chase.com/
-And a very strange combination of der hakenkreutz and SS:
http://www.ferguson.com/

-Lend some credence to crackpot theories selling the idea that something as powerful and resourceful as nazism would have diversified long before the war ended, in order to survive. Or of the possibility that it was an iteration of an Agency which had existed long before the 20th century:
http://www.northe..._own.htm
http://wolfenbuttel.info/
(bottom)
Eikka
5 / 5 (1) Nov 20, 2010
Cost isn't the only problem for hydrogen. It's inherently poor in efficiency due to the number of steps required to store and use it, and its volumetric energy density is very low due to it being the lightest substance there is.

A realistic subcompact car running on liquid hydrogen would manage only about 10-15 miles per gallon, as it carries about 1/4 of the energy in comparison to things like diesel oil. That's a huge problem with the logistics of it.