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GM Moves Ahead on Batteries for Volt; What To Call PHEVs
Jun 11, 2007 (From the CalCars-News archive)
This posting originally appeared at CalCars-News, our newsletter of breaking CalCars and plug-in hybrid news. View the original posting here.
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In a most welcome step, GM has moved several steps closer on selecting lithium-ion batteries for its Volt series plug-in hybrid. Below we include our overall comments, the news, an analysis by Technology Review, and links to other places where you can learn more and post comments. We conclude with a related light but significant story from the Detroit Free Press: as Detroit's media realize that PHEVs are coming, they raise a new issues: the urgent need for a consumer-friendly name for plug-in hybrids!

The reports below project that full battery packs from two suppliers will be tested in labs and vehicles between now and June 2008. One year from now, GM will choose a vendor. GM continues to maintain artificially high requirements, as it has since announcing the Volt, despite pointed questions from many directions. GM's management remains convinced that a car with less than a 40-mile range will be attractive to only a small niche of consumers. (Even though the round-trip commuting "sweet spot" is around 25 miles.) And the need to confirm in advance a 100,000-mile battery lifetime prolongs the development timetable.

In public and private forums, GM has implied that those who suggest starting with long-proven (but heavier) nickel-metal hydride batteries don't understand the complexity of the design process. NiMH proponents understand that GM will design the car's physical space around the lithium-ion battery's requirements. They do suggest GM use that space for a similarly-sized NiMH battery with less range (and of course, design the appropriate charger and other software.) Yes, this is more work, but it could get a demonstration fleet on the road much faster, and, we think, improve the chances that this vehicle will succeed. For a graphic depiction of our view of Prius and GM versions, see a new slide taken from our presentation,­calcars-versions.pdf.

The first five paragraphs of the company press
release give the basic

General Motors has awarded two contracts for advanced development of lithium-ion batteries for its electric drive "E-Flex System," it was announced today at GM's annual shareholder meeting.

GM selected two companies out of the 13 technical proposals it considered to provide advanced lithium batteries for both range-extender electric and fuel cell variants of the E-Flex architecture. The E-Flex electric vehicle architecture underpins the Chevy Volt concept car shown earlier this year and is being developed as part of GM's strategy to diversify transportation away from petroleum.

One contract will go to lithium-ion battery supplier Compact Power, Inc., based in Troy, Mich. CPI is a subsidiary of Korean battery manufacturer LG Chem. A second contract has been awarded to Frankfurt, Germany-based Continental Automotive Systems, a division of Continental A.G., a tier one automotive supplier that will develop lithium-ion battery packs. GM continues to assess other solutions to quickly bring lithium-ion batteries to production.

"The signing of these battery development contracts is an important next step on the path to bring the Volt closer to reality," said GM Chairman and CEO, Rick Wagoner. "Given the huge potential that the Volt and its E-Flex system offers to lower oil consumption, lower oil imports, and reduce carbon emissions, this is a top priority program for GM."

For those who have been following all the candidates for batteries for PHEVs, for the Volt, Contintental Automotive will be working with batteries from A123Systems. (A123, in a partnership with Cobasys, is also contracted to develop batteries for the Saturn VUE PHEV.) For the Volt, CPI/LG-Chem is a new entry. (Not being considered for the Volt is Johnson-Controls-SAFT, still in contention for batteries for the VUE.) Note that the announcement says the company hasn't foreclosed other options as well.

To follow this issue further, you can read postings by Denise Gray, Director, Hybrid Energy Storage Systems, and comments at the GM Fastlane Blog­archives/­2007/­06/­charging_ahead_1.html .

At Green Car Congress­2007/­06/­gm_awards_advan.html, you can read technical details on both battery vendors' products, and read viewers' comments.

Below we've reprinted a longer report from Technology Review. Among the viewer comments you'll see some responses that will interest those who write us asking about AltairNano's long-cycle batteries and EEStor's ultracapacitors. (Quick answer: Altair's products are only beginning to be evaluated by third parties and EEStor has not released anything.)

Technology Review, Thursday, June 07, 2007 By Kevin Bullis New Batteries Readied for GM's Electric Vehicle The technologies behind the battery packs for the GM Volt are being tested and could be ready within a year.­Energy/­18833

This week, General Motors (GM) announced its selection of battery makers to develop and test battery packs for use in its proposed electric vehicles. The selected battery makers, Compact Power, based in Troy, MI, and Continental Automotive Systems, based in Germany, say that they've overcome the performance and cost limitations that have been an obstacle to electric vehicles in the past.

Over the next 12 months, researchers from, Compact Power, Continental Automotive Systems and GM will be testing the battery-pack designs in the lab and in vehicles to confirm that the packs can work for the life of the car--at least 10 years, says Denise Gray, director of hybrid energy storage devices at GM. Initial tests of individual battery cells, along with projections about the performance of battery packs that can contain hundreds of these cells, have Gray optimistic that her company will have proven packs by June 2008.

If the packs perform well, they are slated for use in the proposed Chevrolet Volt, an electric concept car announced by GM in January. The Volt marks a change in emphasis for GM, which previously focused on more distant plans to bring hydrogen-fuel-cell-powered cars to market. The Volt could be ready within a few years. Until now, however, it has been unclear who would develop its advanced batteries.

There are a number of design variations for the Volt, but they will all be propelled by electric motors. In one version, the battery pack, which can be recharged by plugging it in, will provide 40 miles of range. Then an onboard gasoline- or ethanol-powered generator will kick in to recharge the battery, providing an additional 600 miles of range. A proposed hydrogen-fuel-cell version would have a smaller battery pack and no onboard generator.

To make batteries that are up to GM's specifications, battery makers have had to redesign the chemistry of lithium-ion batteries, a type of battery widely used in mobile phones and laptops. While lithium-ion batteries are light and compact, the type of lithium-ion battery typically used in electronic devices relies heavily on cobalt, an expensive metal. The cobalt oxide used in one of the battery's electrodes isn't thermally stable, making the batteries prone to bursting into flame if damaged or poorly manufactured--a shortcoming that led to the massive recall of millions of laptop computer batteries last year. (See "Safer Lithium-Ion Batteries.") This could be a problem in vehicle battery packs, which would be much larger than those in portable electronics, so an accident could be more dangerous.

One alternative is to replace cobalt with manganese. Mohamed Alamgir, director of research at Compact Power, says that manganese-oxide electrodes are significantly more thermally stable than cobalt oxide, and less expensive. The battery maker has also developed a new material for keeping the electrodes separate: the material remains stable at higher temperatures than conventional materials, further guarding against the runaway heating that causes batteries to catch fire. What's more, the company makes the batteries in a flat shape rather than in the typical cylindrical design. Alamgir says this flat shape prevents heat from building up at the center of the cell, making it easier to keep the battery at an even, cool temperature.

A123 Systems, a company based in Watertown, MA, that will supply battery cells to Continental, has taken a different tack, turning to an iron-based cathode that is even more thermally stable than manganese oxide. Better still, iron is cheap and abundant. (See "More Powerful Hybrid Batteries.") The electrodes are not oxide materials but phosphates, a chemistry that more closely binds oxygen, preventing it from being freed from the material, which would allow the battery's flammable electrolyte to catch fire. Such materials do not allow for fast charging or delivery of big bursts of power, so researchers modified them, in part by doping the material and by forming the material as nanoparticles. The A123 batteries were developed for use in power tools but have since been modified to store more energy, making them better suited for use in electric vehicles such as the Volt.

The battery packs for the Volt must include complex electronics for ensuring that each cell is charged and discharged properly. If individual cells are overcharged, for example, the pack can fail. Unlike measuring the gas in a tank, it can be tricky to monitor the exact amount of charge in a cell. So battery makers often include more cells to provide a margin of safety, as a hedge against both running out of power and overcharging the batteries. The pack makers are developing better electronic equipment and algorithms for measuring charge, which could allow them to use closer to the bare-minimum number of cells.

Even as the new battery packs are being tested, GM is developing the rest of the vehicle, especially making sure that it meets targets for weight. Ultimately, Gray says, there could be tradeoffs between vehicle weight and battery size, depending on how the tests go. There's even a chance that expectations for the battery pack's lifetime could be lowered if necessary, although she emphasizes that the goal now is to have battery packs with 10-year lifetimes.

In June 2008, after analyzing the data from a year of testing, GM will evaluate if the technology is where it needs to be and pick a production supplier, Gray says.

Last week, GM's Vice Chairman Bob Lutz was on "On Point," a radio show by Boston's WBUR­shows/­2007/­06/­20070606_b_main.asp. You can listen to it online or download the podcast. Interestingly, as have other GM representatives, Lutz goes out of his way to say ""We don't know how big this can be yet but it is a breakthrough car [The Chevy Volt] because it's not a plug-in hybrid. This vehicle is an electric vehicle. It's driven electrically; it has a small gasoline engine that can be used like an emergency generator set if you run your batteries down to generate more electricity. We're shooting for an all electric range of 40 miles including freeway driving at 70 miles an hour. This thing will have a top speed of 100 miles an hour so it will be a fully functional automobile."

Clearly, someone at GM has decided that "EV" sounds better than "PHEV." In the wake of this show comes one of the stories we find both amusing and very encouraging. "PHEV" has always been awkward -- it describes the feature rather than the benefit. (Like a "9-inkjet printer" instead of a "photo-quality printer.") Many people have tried other names but none have stuck. We believe that when the marketing people starting paying attention, PHEVs will make even faster progress in gaining consumer interest. In that light, we're delighted the Detroit Free Press's columnist raises the issue.

The car above is: A: A hybrid B: An electric C: You tell me MARK PHELAN | BEHIND THE WHEEL June 10, 2007­apps/­pbcs.dll/­article?AID=/­20070610/­COL14/­706100656/­1002

What's in a name?

Plenty if you're talking about the Chevrolet Volt, which General Motors would like to put on the road in a few years. It's been called everything from the environmental breakthrough that could redefine GM to a transparent marketing ploy.

The Volt is such a different kettle of fish that around the newsroom, we can't even agree on how to describe its propulsion system, which combines big batteries with a small gasoline engine. The gas engine charges the batteries, but you can also charge them by plugging the Volt into a wall outlet.

Depending on how far you drive, gasoline consumption ranges from zero -- pure electric power up to 40 miles -- to 50 m.p.g. -- what you'd get from a single tank of gas on a long continuous drive with no stops to charge the batteries from an outlet.

GM appears to be serious about building the Volt, although the die-hard skeptics dismiss it as a marketing gimmick. They think GM cooked up the idea to look environmentally aware while it pumps out a few hundred thousand Hummer H2s.

Whether the idea works or not -- the technical hang-up is developing a powerful and sophisticated new kind of battery -- we're going to be talking and writing a lot about the Volt over the next few years.

That's why we have to figure out what to call it. Existing terms don't fit, and I'm looking for suggestions.

Here are the names we're stuck with today, and my handicap on them:

Hybrid. Won't do. Technically, only electricity powers the car when you put your foot on the pedal. The Volt's system would be far more elegant and efficient than current hybrids, which essentially carry around two drivetrains, one electric and one internal combustion.

Plug-in hybrid. Accurate, but a loser. The name combines the worst attribute of electric cars -- "You mean I have to plug it in?" -- with a ho-hum, nothing-to-see-here sense that it's just another hybrid.

Series hybrid. The engineer's choice, which is all you have to know about what's wrong with it. It has the virtue of accuracy -- the electric and gasoline systems work together, rather than as separate-but-equal systems in current parallel hybrids. That's swell, but I write about this stuff all the time, and even I can't keep the difference between series and parallel hybrids straight.

Electric car. Call out the truth squad. The gasoline generator may be small and extraordinarily efficient, but it's there, and it allows the Volt the long cruising range no pure electric car could offer.

Extended-range electric vehicle. GM's term of choice has all the zing of calling a wedge of 6-year-old Gouda cheese "stale milk by-products." Too long and boring for the vehicle that might be the next big thing. It's got some chops as an acronym, though. "E-rev" sounds fast and slick and modern. The downside is continually explaining what it means.

For the moment, at least, the Free Press has decided to call the Volt electric-powered or electric-drive. Neither of those exactly sings the body electric, though, so come up with something that crackles like a Tesla coil and drop me a note.

Contact MARK PHELAN at 313-222-6731 or phelan@....

Your thoughts?

How do you think the Volt should be described? Leave a message in the forum by clicking below or e-mail me a note at phelan@... with your suggested name and a brief description of why you think it captures the essence of what makes the Volt go.

I can't promise to use any of them, but we'll print the most entertaining and interesting in this space next week.

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