Portable Fuel Cells: Coming Soon?
New technology may lead to smaller, cheaper, and lighter alternative power sources.
Martyn Williams, IDG News Service
Tuesday, January 20, 2004
A California start-up has made an advance that
it says stands to make Direct Methanol Fuel Cells--envisaged as a
future power source for mobile electronics devices--smaller, cheaper,
and lighter.
PolyFuel's development of a new Direct Methanol Fuel Cell
(or DMFC) membrane comes as several of the world's largest electronics
companies are developing fuel cells with a view to commercializing them
later this year or next year.
The membrane is a small piece of plastic that
looks something like sandwich wrap, according to PolyFuel President and
CEO Jim Balcom. It sits at the heart of the DMFC separating a mixture
of methanol and water from a catalyst. It's the electrical potential
across the membrane that is the key to power creation however the
current most popular membrane isn't well suited for use in DMFC
applications, Balcom says.
"Until now all of the manufacturers, and we've
counted 35 organizations working on DMFCs, have been hampered because
they have had to use a hydrogen fuel cell membrane that was developed
40 years ago. It has been the only one available for DMFC applications
and they are very different technologies," he says.
Increased Concentration
The biggest problem developers have is stopping
methanol crossing over the membrane--something that lowers overall
efficiency of the fuel cell because fuel is wasted and it also results
in generation of heat. To combat this problem researchers have kept
methanol concentrations relatively low, at around 10 percent although a
higher concentration would be better, says Balcom.
His company's new membrane allows for much
higher concentrations--between 50 percent and 100 percent--and this
should mean DMFCs can be made one-third smaller, lighter, and less
expensive, he says.
Increasing the methanol concentration has been a stated goal of several companies developing DMFCs for some time.
Product Plans
NEC, which plans to commercialize a DMFC for notebook computers
this year, is currently using a methanol concentration of around 10
percent in its prototype, and Toshiba, which has shown a prototype
battery charger based on DMFC technology, says it uses a concentration
of between 3 percent and 6 percent.
Hitachi plans a DFMC
for use in PDAs and says it hopes to raise methanol concentration from
around 20 percent to 30 percent by the time the produce is
commercialized in 2005.
PolyFuel's new membrane is already in sample
production and initial feedback from the company's potential clients is
good, says Balcom. The company's current production capacity in Silicon
Valley is anticipated to be enough to handle customer demand though
2005 and further expansion will be based on demand, he says.
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