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.
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.
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.
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.
I agree, Beth, that it would be a shame to lose the momentum that the EV market has gained in the past five years. In the long run, though, I think the momentum won't be completely lost. I believe we'll see that momentum swing to hybrids and plug-in hybrids, which can use smaller lithium-ion batteries that inherently cost less. If we're going to continue publicly pushing pure EVs, it might be better for us to direct our efforts toward battery research. I don't believe we'll ever see a battery that can compete with the energy and cost characteristics of gasoline in our lifetimes, but if we could create a battery that could meet the old $100/kWh target, it would go a long way toward bringing pure EVs to the masses.
@Alexander Wolfe: The days of throwing huge sums of money at fuel cell research pretty much ended with the Bush Administration. Besides the issues which Charles cites, there is the larger issue of where to get hydrogen from. It may be the most abundant element in the universe, but here on earth, it's mostly tied up in water and hydrocarbons. If you want to separate the hydrogen from these compounds, you need to put energy in. Where do you get that energy from?
At best, hydrogen is an energy storage medium, not an energy source. And as an energy storage medium, its energy density is much less than that of batteries.
You're absolutely correct that most of the safety concerns about hydrogen are unfounded. However, that doesn't mean the technology makes sense.
I did some work on hydrogen fuel cell technology for the Department of Energy as an undergraduate. It was very interesting from a materials engineering point of view -- and it was inspiring to feel like I was helping to lay the groundwork for an energy revolution which would someday break our dependence on carbon-based fuels. However, the more I learned, the more skeptical I became that hydrogen will ever be either environmentally sustainable or economically viable.
A couple years later, I worked briefly for a professor who was building a hydrogen-powered lawnmower as a demonstration project for a major city's parks department. He kicked me off the project after I asked too many "big picture" questions which he couldn't answer.
Good comments, Dave. Interesting how promising technology changes when you move it from the lab and into production. In your case, I guess it didn't look like promising technology even when it was in the lab.
I agree, Rob. Battery technologies have been notorious for looking good in the lab but not as good in production. I started covering electric cars in '88, and back then every battery looked great in the lab. Virtually every battery maker promised to bring vehicle range up to 300 miles and cost down to $100/kWh. One academic said that it was like being in "a liar's contest. Whoever told the biggest whopper got the most money." But for two decade now, these technologies have never quite realized their promise when they leave the lab.
As I sit alone, late at night hiding behind my pseudonym and reading about batteries and safety, a couple of thoughts cross mind.
1. What are the NH-TSAs doing? Do they just look at dents and crash dummy damage? I would expect that they [if they were a company in the private sector] would perform some level of 'autopsy' after a crash test - especially if it involved a 'not very common technology' like battery power.
2. 'Instant gratification types' and 'academians' are always whining about the lack of infrastructure when something a little different might come to market. That would be nice and make for quick adoption, but it is contrary to the mass deployment of any new product that comes to mind. What was the infrastructure when the first automobiles were being sold? Or when the first mobile phones and cable TV service were sold in the 1940s?
mellowfellow, I agree with your statement in regards to the NHTSA post testing procedure. In the event that I had a crash that totalled the rear end of my car and it was leaking gasoline, I would surely immediately have the tank repaired or removed to stop the potential fire hazzard. I would not wait three weeks without doing anything.
Mellow, the problem of early adoption does not seem the same now as it was then.
Take light bulbs. The Edison Screw is by far the most widely accepted. Even new CFL bulbs are using this century old design. There were competing designs (and still are), but the lead early adopter pushed his design into the de-facto standard.
Gasoline nozzles are the same way. Petroleum companies early on saw the BENEFIT of commonality; they could push more of their product if all vehicles had the same receptacle.
Today, there's not many instances where an innovator make such a leap that nearly everyone sees the benefit of following the de-facto standard. Companies see an opportunity to create their own "standard" hoping more people will follow them than the competition. VHS vs. Betamax, Blu-Ray vs. HD-DVD are good examples where competition caused early adoption grief.
Consumer battery sizes (AA, AAA, C, D) are all over a century old, though the sizes were formally ratified as ANSI standards in the USA in the 40s and 50s.
It's not a matter of "something a little different". If producers would be willing to standardize even a little bit, the infrastructure problems would be much less.
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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