May/June 2008

An Electrifying Startup

A new lithium-ion battery from A123 Systems could help electric cars and hybrids come to dominate the roads.

By Kevin Bullis

Side Impact: A battery designed by A123 Systems for GM’s Volt electric vehicle can survive a crushing safety test. The high-velocity impact could have caused other lithium-ion batteries to overheat and catch fire. Credit: Porter Gifford

Multimedia •  Learn how different kinds of hybrids work using this interactive primer.   Yet-Ming Chiang discusses his new lithium-ion battery electrode.

Reporter's Notebook: Kevin Bullis

It is the quickest electric motorcycle in the world. On a popular YouTube video, the black dragster cycle nearly disappears in a cloud of smoke as the driver does a "burn-out," spinning the back wheel to heat it up. As the smoke drifts away, the driver settles into position and hits a switch, and the bike surges forward, accelerating to 60 miles per hour in less than a second. Seven seconds later it crosses the quarter-mile mark at 168 miles per hour--quick enough to compete with gas-powered dragsters.

What powers the "Killacycle" is a novel lithium-ion battery developed by A123 Systems, a startup in Watertown, MA--one of a handful of companies working on similar technology. The company's batteries store more than twice as much energy as nickel-metal hydride batteries, the type used in today's hybrid cars, while delivering the bursts of power necessary for high performance. A radically modified version of the lithium-ion batteries used in portable electronics, the technology could jump-start the long-sputtering electric-vehicle market, which today represents a tiny fraction of 1 percent of vehicle sales in the United States. A123's batteries in particular have attracted the interest of General Motors, which is testing them as a way to power the Volt, an electric car with a gasoline generator; the vehicle is expected to go into mass production as early as 2010.

In the past, automakers have blamed electric vehicles' poor sales on their lead-acid or nickel-metal hydride batteries, which were so heavy that they limited the vehicles' range and so bulky that they took up trunk space. While conventional lithium-ion batteries are much lighter and more compact, they're not cost effective for electric vehicles. That's partly because they use lithium cobalt oxide electrodes, which can be unstable: batteries based on them wear out after a couple of years and can burst into flame if punctured, crushed, overcharged, or overheated. Some auto­makers have tried to engineer their way around these problems, but the results have been expensive.

A123's batteries could finally make lithium-ion technology practical for the auto industry. Instead of cobalt oxide, they use an electrode material made from nanoparticles of lithium iron phosphate modified with trace metals. The resulting batteries are unlikely to catch fire, even if crushed in an accident. They are also much hardier than conventional lithium-ion batteries: A123 predicts that they will last longer than the typical lifetime of a car.

The battery's promise has made A123 one of the best-funded technology startups in the country, with $148 million in venture capital investments so far. With the funding, A123 has been pursuing an ambitious business plan that calls for it to do everything from perfecting the material to manufacturing batteries and selling them to customers in the auto and power-tool industries.

The A123 batteries for GM's Volt store enough energy for 40 miles of driving, enough to cover daily commutes. (On longer trips, the small gasoline engine would kick in to recharge the battery, extending the range to more than 400 miles.) GM plans to sell the vehicles for around $30,000 to $35,000; the company thinks it can sell hundreds of thousands at that price in the first several years, and J. D. Power and Associates estimates that GM will sell nearly 300,000 by 2014.