Sankar and the Battery Factory
How is a battery like chocolate?
In the book, Charlie and the Chocolate Factory (Roald Dahl, 1964), Willy Wonka owns the world's largest candy factory. In the real world, Sankar Das Gupta, PhD is president and CEO of the company Electrovaya.
Wonka uses his childlike imagination to create fantastical treats that astound the reader. Das Gupta uses his extensive experience in electrochemistry to create polymeric lithium-ion (Li-Ion) batteries which could revolutionize the electric vehicle industry.
Wonka's factory makes delicious confections of various shapes, sizes and flavors. Electrovaya makes innovative batteries in different shapes, sizes and capacities.
Wonka employs hordes of "Oompa Loompas" to sing songs and do his bidding. Das Gupta... well... I would be willing bet that the Electrovaya factory is staffed by human beings.
Electrovaya creates "a world of pure imagination" not by hiring elf-like employees, but rather by creating batteries which can fit into designs limited only by our creativity. How many readers remember the obtrusive central tunnel in the GM EV1? How many of you are frustrated because the Honda Civic hybrid does not have a fold-down rear seat? In the past, EV designers have struggled to fit batteries into their vehicles, and the necessary compromises have been annoying at best. With Electrovaya's polymeric Li-Ion battery design, EVs not longer have to be designed around the size and shape of the batteries; batteries can now be shaped to fit the available space. That's right, Electrovaya's batteries could be molded into shapes that would fit snuggly in all the nooks and crannies of wasted space in any car.
Also, traditional cylindrical Li-Ion batteries are so small that companies such as Tesla Motors and AC Propulsion must use thousands of them, connected in precarious strings, to power their EVs. Polymeric Li-Ion batteries can be created in a wide range of capacities, drastically cutting the required number of cells in each vehicle. Dr. Das Gupta explained that each cell in a polymeric Li-Ion battery pack can have more than ten times the energy storage capacity of a typical 2.5 Ah Li-Ion cylindrical cell.
Furthermore, Dr. Das Gupta stated, "Our polymeric Li-Ion batteries can actually be used as part of the structure of the vehicle." Instead of fitting batteries into a chassis, the batteries could become part of the chassis. If that concept does not fire up an EV designer's imagination, he/she is in the wrong business.
However, design flexibility is not Electrovaya's only benefit. Safety is inherent in the polymeric Li-Ion chemistry. "These batteries cannot go into thermal runaway," Dr. Das Gupta explained, "The cathode in a polymeric Li-Ion battery cannot easily produce oxygen." It is rapidly-produced oxygen from the cathode that fuels combustion in other Li-Ion batteries. Take the oxygen out of the picture, and the combustion never starts.
Added to these features are the "standard" benefits of Li-Ion batteries. They are far lighter than other battery chemistries. Electrovaya claims and energy density of 230Watt*hours/kg, which is competitive with specifications on batteries from Valence and other Li-Ion manufacturers.
Dr. Das Gupta and his staff were not satisfied to merely speculate on how well their batteries would work in an EV. Instead, they built the Maya-100 as a test-bed. Using GM's mini-SUV "Tracker" model as the glider for their project, Electrovaya built a ground-up EV drivetrain. For safety reasons, they decided to use a much lower voltage system than those seen in other EVs. While recent EV designs have specified a buss voltage of roughly 400VDC, the Maya-100 runs on 120-130 volts. In order to efficiently harness the lower voltage, Electrovaya engineers designed a new motor which would give them the desired performance characteristics. Of course, the new motor required an all-new control system, which Electrovaya created as well.
When the engineering and fabrication were finished, the Maya-100 surpassed everyone's expectations. It demonstrated a range of up to 230 miles and could cruise at the electronically-regulated top speed of 80 mph. While lead-acid batteries stop working in below-zero temperatures, the polymeric Li-Ion batteries in the Maya-100 kept delivering power throughout winter testing in and around Electrovaya's headquarters in Ontario, Canada. The Maya-100 was so impressive that it won the Best Battery Electric Vehicle and the Technology awards at the 2004 Tour de Sol.
I asked Dr. Das Gupta about Electrovaya's future EV plans. "We are currently working on several electric vehicle projects, including a riding lawn mower which should be able to mow an 18-hole golf course on one charge. We are also developing an off-road vehicle and a courier vehicle. Another project we have is a collaboration with a Norwegian company. We are creating an electric vehicle based on the Daimler Smart Car."
Dr. Das Gupta feels that Norway has the highest potential of any nation for developing a significant EV market in the near future. Clean hydroelectric power, new laws, and social consciousness combine to make Norway a hotbed of EV development. EVs made by Peugeot, Renault, Think and Kewet are already available to Norweigians.
Electrovaya is also developing plans for a new five-passenger electric vehicle based on a commonly-available 2007 automotive platform which Dr. Das Gupta declined to name. He is also looking at various projects related to the $10M PHEV initiative recently announced by New York State.
"I am a tremendous fan of EVs," he told me, "But not on an emotional basis. I think the timing is right. I think the tipping point has arrived."
With the recent vehicle introductions by Tesla Motors and AC Propulsion, and with battery developments such as those achieved by Electrovaya, I am inclined to agree.
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