Lithium Batteries On The Way For Hybrids

In just one year, the whens and wheres of lithium battery packs for hybrid and electric cars have come into much sharper focus

PHOTO: Israel Hadari/Project Better Place

Tampa, Fla.—Already intense, the global auto industry’s interest in lithium-ion batteries for electrically driven cars came into sharper focus at the largest-ever Advanced Automotive Battery & Ultracapacitor Conference (AABC). Fully 30 percent more people than last year—close to 1000 altogether—registered for this year’s event, held in the pleasant May sun of this Gulf Coast city.

Much has changed since last year’s AABC, in Long Beach, Calif. Several automakers have now committed to dates for using lithium battery packs in vehicles, ranging from Mercedes-Benz’s S400 hybrid, a mild hybrid to go on sale later this year, to the much-vaunted Chevrolet Volt extended-range electric vehicle, targeted for November 2010. Japanese makers continue to test and plan for the limited production of small all-electric cars. And while the pace of rollout will be slow, the main question has moved from ”Are the cells safe and reliable?” to ”Will they be affordable for mass production?”

Befitting the global nature of the battery industry, AABC provided simultaneous translation into (and from) Japanese for all presentations. ”I wanted to present in Japanese,” joked Sung-Soo Kim of Samsung SDI, ”but my boss says I must do it in English!”

One well-attended presentation was given by Nobuaki Yoshioka of Automotive Energy Supply Corp. (AESC), a recent joint venture between Japan’s NEC Corp. and Nissan Motor Co., to design and build batteries for electric vehicles. While his talk largely dealt with the company’s current generation of cell, he described in general terms a better-performing cell that AESC plans to introduce in coming years, based on manganese cathodes in very thin sheets that are laminated to form cells. Not only will this cell power small EVs in 2010—for both Japan and export markets—it will also provide the basis for the much-discussed Project Better Place.

This ambitious effort, launched last October by entrepreneur Shai Agassi, aims to provide Israel and Denmark with electric vehicles by 2011. (Why those two countries? Because they have committed to significant tax incentives for pure electric vehicles.) The cars will be built by Renault and powered by AESC’s cells, in leased battery packs that can be ”hot swapped” in just a few minutes at a charging network. In this case, hot-swapping—usually applied to changing electronic components—means removing a battery pack of 100 kilograms or more from the car’s chassis and replacing it with another one while the driver waits. Project Better Place’s goal is for the entire process to take no longer than a full fill-up for a gasoline vehicle. Drivers, meanwhile, will pay based on the distance they travel, even if longer trips require such pack swaps.

In theory, this would permit EV owners unlimited local range without the fear of fully discharging their batteries and having to wait hours for a recharge—not to mention paying thousands of dollars for a replacement pack if theirs goes bad. Many auto engineers are highly skeptical about the technology for swapping a heavy, and most likely structural, battery pack, but Agassi has commitments for US $200 million in funding, so clearly the industry is intrigued by his attempt to shift the paradigm of vehicle operating costs.

The fast-evolving nature of the industry also led AABC organizer Menahem Anderman to limit his projections for battery markets; last year, he’d generated much comment—far from all of it favorable—by issuing projections through 2015 that were far more pessimistic than most other industry analysts’. This year’s projections covered only the years 2008 through 2010. Of a total automotive high-voltage battery market of $1.4 billion in 2010, Anderman projected that the lithium-ion portion would be less than $100 million—reflecting the slow ramp-up of production with what will still be very expensive packs.

But sometimes, looking farther ahead is irresistible. Pete Savagian, power-train development manager for Chevy’s Volt, explained the costs and benefits of including an ultracapacitor in the next generation of its E-Flex electric-drive architecture (projected for 2015 or later). Bear in mind that the first E-Flex won’t launch (in the Volt) until the very end of 2010, yet Savagian was suggesting a technical direction seven or more years out.

In brief, ultracapacitors can offer complementary benefits to lithium-ion battery packs—copious power for short periods, almost complete energy discharge, and excellent cold-temperature performance. Using them during periods of highest power demand might allow a smaller battery pack to be skewed toward energy storage by supplementing its lower power. We’ll hear much more about ultracapacitors, especially as people look to overcome the downsides: cost, the danger of extremely high voltages, and the significant challenges of integrating yet another component into a mix already comprising battery packs, electric motors, regenerative braking, and combustion-driven power generation.

Unexpectedly, talk circulated around the significant difficulties that large U.S. automakers were said to be having in sourcing electric machines for future hybrids, plug-in hybrids, and extended-range EVs. One rumor even had GM quietly evaluating building its own electric motors—which it hadn’t done since the demise of the EV1 electric car, almost 10 years ago.

While you might think the world is overflowing with companies that could provide automotive-grade electric motors of 100 to 200 kilowatts, it’s not quite that simple. First, a supplier has to meet extraordinarily high reliability standards. Then it has to be able to ramp up to supply tens or even hundreds of thousands of motors within a few years—and at margins low enough to have bankrupted more than a dozen major U.S. auto-parts suppliers. As one industry analyst cracked dismissively, ”What’re you gonna do, call the forklift industry?”

About the Author

John Voelcker has written about automotive technology and other topics for 20 years. He covered software and microprocessor design for IEEE Spectrum from 1985 to 1990.

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