None of this would be an issue, of course, if EV battery packs weren't so big in the first place. The packs, often weighing more than 400 pounds, can have trouble releasing their heat, because they're so much bigger than laptop or cellphone batteries. That's why most electric car makers are employing complex active cooling systems that cellphones don't need.
"Can you put cooling channels" in an EV battery pack, Sadoway asked. "Sure. But they may not hit the price point you want."
Researchers are working on new chemistries that could supplant the lithium-ion formula, but such batteries are still a long way from production. Lithium-sulfur, which is said to have higher energy and better heat characteristics, could reach production for small products, such as laptops, in the next 10 years. Lithium-air, long talked about as a high-energy replacement for lithium-ion, might be two or three decades from widespread use, Cairns said. Batteries based on other metals, such as magnesium, are also under consideration.
The bottom line is that today's technology of choice may be facing challenges ahead. Automakers are relying on a steep drop in battery cost to help electric car sales take off. And additional safety constraints aren't going to help them reach their cost targets, especially since cost was already an issue before the Volt fires.
"My position is that we must get beyond lithium-ion for vehicles," Cairns said. "The lithium-ion systems of today are inherently too expensive and too low in energy for electric vehicles. If we use lithium-ion as we now know it, the EV will always be a specialty vehicle."
For a deep look a GM's Chevy Volt, we recommend you go to the Drive for Innovation site and follow the cross-country journey of EE Life editorial director Brian Fuller. In the trip sponsored by Avnet Express, Fuller is taking the fire-engine-red Volt to innovation hubs across America, interviewing engineers, entrepreneurs, innovators, and students as he blogs his way across the country.
There's no doubt that the word "hydrogen" has a fear factor associated with it. But experts have pointed to additional issues with hydrogen fuel cells. At a recent UBM-sponsored panel discussion at the Embedded Systems Conference, experts cited three issues with fuel cells: outgassing, storage and infrastructure. But I think much of the problem comes down to this: In a sense, we've all been spoiled. Gasoline-burning cars are marvelous machines and they've raised our expectations so high that it's difficult for any new technology to come in and match up. Automakers are now tasked with satisfying incredibly high consumer expectations. If they don't build reliable machines, they'll be rightfully flooded with complaints from people who've invested $30K or $40K in their shiny new vehicles.
The plethora of ongoing engineering challenges with electric vehicles -- specifically, the cost of batteries (as discussed in this article) and their apparent vulnerability to fires) -- makes me wonder why fuel-cell vehicles are completely off the table. Only two years ago, Honda and several other automakers demoed hydrogen fuel-cell cars at major auto shows. These are ready to go; the big impediment is a complete lack of infrastructure. I still don't get why these vehicles have been ignored. It's a workable, safe technology. Maybe the word "hydrogen" scares people.
Kind of a sobering post, Chuck, but very enlightening. Based on what you outlined, it seems likely that refining Li-ion batteries and cooling system designs are likely only to deliver incremental benefits in terms of lowering costs--not nearly enough to move the bar in terms of sparking sales. As far as developing alternatives to Li-ion batteries, that seems like a long way off. It would be a shame to lose ground given how far we've come in the last five years in terms of wannabe acceptance of the EV as a mainstream vehicle.
Tesla Motorsí $35,000, 200-mile electric car may not revolutionize the auto industry by itself, but it could serve as a starting point for a long, steady climb to a day when half of the worldís vehicles will be plug-ins.
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