ELECTRIC AUTO
TECHNOLOGY
The future of
battery electric vehicles depends primarily upon
the cost and availability of batteries with high
energy densities, power density, and long life,
as all other aspects such as motors, motor
controllers, and chargers are fairly mature and
cost-competitive with internal combustion engine
components. Li-ion, Li-poly and zinc-air
batteries have demonstrated energy densities
high enough to deliver range and recharge times
comparable to conventional vehicles.
Bolloré a French
automotive parts group developed a concept car
the "Bluecar" using Lithium metal polymer
batteries developed by a subsidiary Batscap. It
had a range of 250 km and top speed of 125 km/h.(Bluecar)
document
The cathodes of
early 2007 lithium-ion batteries are made from
lithium-cobalt metal oxide. That material is
expensive, and can release oxygen if its cell is
overcharged. If the cobalt is replaced with iron
phosphates, the cells will not burn or release
oxygen under any charge. The price premium for
early 2007 hybrids is about US $5000, some $3000
of which is for their NiMH battery packs. At
early 2007 gasoline and electricity prices, that
would break even after six to ten years of
operation. The hybrid premium could fall to
$2000 in five years, with $1200 or more of that
being cost of lithium-ion batteries, providing a
three-year payback.
Experimental
supercapacitors and flywheel energy storage
devices offering comparable storage capacity,
higher charging rates, and lower volatility have
the potential to overtake batteries as the
prominent rechargeable storage for EVs. The FIA
has included their use in its sporting
regulations of energy systems for Formula One
race vehicles in 2007 and 2009, respectively.
EEStor claims to have developed a supercapacitor
for electricity storage. These units use barium
titanate coated with aluminum oxide and glass to
achieve a level of capacitance claimed to be
much higher than what is currently available in
the market. The claimed energy density is 1.0 MJ/kg
(existing commercial supercapacitors typically
have an energy density of around 0.01 MJ/kg,
while lithium ion batteries have an energy
density of around 0.54–0.72 MJ/kg). EEStor
claims a less than 5 minute charge should give
the supercapacitor sufficient energy to drive a
car 400 km (250 mi).
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