Autos | Batteries

Future of electric cars rests with battery quality

SAN JOSE, Calif. — Electric cars are a game-changing technology with an Achilles' heel — the battery. • Current batteries are expensive and have limited range, making it hard to drive significant distances without stopping to recharge. Experts agree consumers will never fully embrace electric vehicles until they can travel as far as a gas-powered car on a single charge. • So the global race is on to build a better lithium-ion battery, one that pulls off the herculean feat of extending range while being long-lasting, affordable, quick-charging and safe.

In Asia, governments and big battery companies are investing in next-generation battery technology, while in the United States much of the cutting-edge research is being performed at Department of Energy labs and universities. The San Francisco Bay Area — home to Palo Alto, Calif.-based Tesla Motors, Lawrence Berkeley National Laboratory and two dozen battery startups — has emerged as a hub of battery innovation.

"Transportation is going to go electric, and batteries have become a real critical technology," said Steve Visco, chief technology officer of PolyPlus, a startup that was spun out of the Berkeley lab. "The Chinese government is subsidizing a lot of battery research, and in Japan the companies have 10-, 20- and 30-year technology road maps."

The stakes are high. President Barack Obama wants to see 1 million electric vehicles on America's highways by 2015, but many say that goal will be hard to reach until range improves.

"The perception of range anxiety is a real challenge for us," Renault-Nissan CEO Carlos Ghosn, whose company makes the all-electric Nissan Leaf, said at Stanford University last month. "People are anxious because it is a double dip — the range is limited, and then if I am stuck, where can I charge?"

Batteries convert stored chemical energy into electricity. Researchers say advances often involve trade-offs: Improving range may result in skyrocketing costs, or a shorter battery life.

Measured as kilowatt hours per kilogram or liter, "energy density" determines range: The more watt hours, the more miles the car can travel on a charge. Low-cost, high-energy density batteries are the holy grail.

"If you could go 300 miles on a charge, you'd see significant growth in electric vehicles," said Michael Omotoso, auto analyst with J.D. Power and Associates. "We think battery costs will come down due to volume manufacturing, but we don't see energy density going up that much."

The Tesla Roadster, Nissan Leaf and Chevrolet Volt all use some form of lithium-ion chemistry in their batteries. First commercialized by Sony in 1991, lithium-ion batteries are widely used in consumer electronics such as laptops and cellphones but are relatively new in cars.

"Everyone is moving rapidly up the technology curve," said Jim Dunlay, Tesla's vice president for powertrain hardware engineering. "Lithium-ion is still on a strong trajectory; it hasn't peaked.. . . But it's not just about building a better battery. A better battery means we have a better car."

Future of electric cars rests with battery quality 08/02/11 [Last modified: Tuesday, August 2, 2011 5:30am]

    

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