Soaring fuel costs have left automakers reeling, with the
impact on their bottom lines forcing many to slash jobs, close
some plants and retool others to produce more fuel-efficient
vehicles. The need to economize is driving a revolution of
sorts the rise of plug-in hybrid electric vehicles (PHEVs).
Electricity is 50 to 75 percent cheaper than the equivalent
cost of a gallon of gas. The mix of energy sources used to
generate North America's electricity supply is also lower
priced and more stable than that of oil.
The race is on to come up with the best power source for
electric vehicles, and there's no shortage of contenders. The
two leading technologies appear to be lithium-ion and upgraded
nickel-metal hydride (NiMH) batteries.
Tokyo-based automakers Toyota Motor Corp. and Honda Motor
Co. Ltd., the leaders of PHEV technology, are leaning toward
the NiMH battery, while Nissan Motor Co. Ltd. and NEC Corp.,
also based in Tokyo, are developing a high-powered lithium-ion
Electric vehicles are already on North American roads, but
haven't made it onto highways yet because of their limited
range and speed.
Eestor Inc., Cedar Park, Texas, is another contender with
its electrical energy storage unit, which it claims will have
more than three times the energy density than the top
lithium-ion batteries today, will last longer and will recharge
in less than five minutes compared with three hours for
lithium-ion batteries. It also weighs 300 pounds vs. 752
Those claims have been challenged by some experts, who
maintain that it's difficult to compare different battery
technologies when none is yet on the market and some are
specifically designed to be charged overnight.
Altair Nanotechnologies Inc., Reno, Nev., is developing a
battery that can power a PHEV for 150 miles and recharge in the
same amount of time it takes to fill up a gas tank. The device
is based on 40-nanometer-size particles of lithium and titanium
to make a coating that covers a battery's anode, and an
aluminum bar that carries electricity to and from the vehicle's
In contrast, most hybrid cars use a graphite coating in
conjunction with NiMH or lithium-ion batteries. The difference
lies in the material. When a battery operates or recharges,
ions pass through the coating of the anode. Graphite isn't very
porous, so the ions literally deform the material as they force
their way through.
"Graphite anodes produce an SEI (solid electrolyte
interface) on the anode in a standard lithium-ion battery. This
SEI is basically an internal electrical resistor in the battery
cell," said Chet Sandberg, Altair's technical strategy manager.
"The Altair nanotechnology has no SEI and consequentially less
internal heating. Our technology places our power storage cells
between a super capacitor and a standard battery in operational
Altair said its nano-titanate battery lasts for 20,000 full
recharge cycles, or about 20 years-four times the life span of
a comparable NiMH or lithium-ion battery.
What all these new developments mean for lithium-ion
batteries is unclear, according to Prabhakar Patil, chief
executive officer of Compact Power Inc., Troy, Mi., a major
supplier of lithium-ion batteries. "The cost ratio of lead-acid
batteries and lithium-ion is six to one in favor of lead-acid,
but the lead-acid battery life cycle is only three years vs. 10
for lithium, and the space and weight ratio favors lithium by
four to one," he said.
And while Toyota and Honda favor the NiMH battery, by 2010
they will start to shift to the improving lithium-ion
technology, Patil predicted. "Lithium-ion batteries will be
No.1 on the market within the next 15 years," he added.
As for numbers, Patil noted that General Motors Corp.,
Detroit, expects to sell 10,000 of its Volt PHEVs in 2010 and
60,000 annually by 2012, while all original equipment
manufacturers (OEMs) expect to sell a total of 1 million PHEVs
in 2015 in the United States alone.
"The Volt's highway model will have 150 to 200 horsepower,
which will match the performance of gas-powered cars," Patil
said. BRIAN DUNN