Transcript
The
pathway to zero-emission vehicles has taken two forks, one toward battery
electric cars like the Tesla and the other toward fuel-cell-powered automobiles
like the Toyota Mirai. At Business Briefings, we believe that fuel-cell
vehicles are the way to go, because they best preserve the advantages of
gasoline automobiles: low upfront cost, long driving range and fast
refueling. But to achieve this, a new fuel-cell technology may be
necessary.
To make
fuel-cell cars a cost-effective reality, the U. S. Department of Energy (or
DOE) has set a system cost target of $30 per kilowatt, which translates into
about $2,400 per car. Right now, the cost for a polymer electrolyte
membrane fuel cell (or PEMFC) is about $52 per kilo-watt. That's a big
improvement over where the technology, started but not yet good enough.
But now,
according to a paper published in the journal Small, researchers at the University of California,
Riverside, have developed an inexpensive,
efficient catalyst material for a PEMFC, which turns the chemical energy of
hydrogen into electricity and is among the most promising fuel cell types to
power cars and electronics.
The
catalyst developed at UCR is made of porous carbon nanofibers embedded with a
compound made from a relatively abundant metal such as cobalt, which is more
than 100 times less expensive than platinum.
A
critical barrier to fuel cell adoption is the cost of platinum, which amounts
to about $12 per kilo-watts in current designs.
Using a
technique called electrospinning, the UC Riverside researchers made paper-thin
sheets of carbon nanofibers that contained metal ions of cobalt, iron or
nickel. Upon heating, the ions formed ultrafine metal nanoparticles that
catalyzed the transformation of carbon into a high-performance graphitic
carbon. Subsequently, the metal nanoparticles and residual non-graphitic
carbon were oxidized, leading to a highly porous and useful network of metal
oxide nanoparticles dispersed in a porous network of graphite.
In
collaboration with a team at Stanford University, they determined that the new
materials performed as well as the industry standard platinum-carbon systems,
but at a fraction of the cost.
Another
important challenge in making high-performance vehicles is reducing weight,
both from the body of the vehicle and extra weight from the battery or fuel
cell, without affecting safety or performance. The researchers speculate
that the new PEMFC material may reduce weight by enabling automakers to turn
structural components, such as the hood or the chassis, into functional fuel
cell elements which help power the car.
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