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Building Batteries for Electric Cars

A123’s new factory exploits automation and advances in nanotechnology.
February 22, 2011

Quentin Sharpe, a technician in A123 Systems’ new battery factory in Livonia, Michigan, takes a foil packet out of a white plastic container and sets it down within reach of a robot, which scoops it up and adds it to a growing stack of metal plates and foil packets. It’s the start of a process that makes one of the dozens of types of battery packs assembled here—all of which will power advanced hybrid and electric vehicles designed to cut petroleum consumption.

A technician assembles a battery pack at a factory in Livonia, Michigan. See the slideshow (and below) for a step-by-step guide to making automotive batteries.

Production of advanced lithium-ion batteries for electric cars and hybrids has so far been dominated by companies in Asia, but the U.S. government hopes to see it become a major new industry in the United States. The new factory will have the capacity to produce 30,000 battery packs a year once all its equipment is up and running (A123’s plans call for the factory to be fully operational by this spring). It is one of nine that the U.S. Department of Energy helped fund in a $2 billion program created under the American Recovery and Reinvestment Act of 2009. A123 received $249 million in government funding for two facilities, which it matched with additional money from private sources. “Just a few years ago American businesses could only make 2 percent of the world’s advanced batteries for hybrids and electric vehicles—just 2 percent,” President Obama said when he called in to the factory’s opening ceremony last fall. The new factories are meant to help increase the U.S. share to 40 percent of the world’s capacity.

That hope could be a long shot. Besides facing stiff competition from manufacturers in Asia, U.S.-based factories have to contend with a challenge inherent in new industries: no one knows exactly what kinds of cars powered by the new batteries will sell, or how well. Thus it’s unclear which batteries, or how many of them, need to be built.

To address that uncertainty, A123 has designed a flexible factory that can make many different kinds of lithium-ion battery packs. All begin with the same basic building block: a battery cell in the form of the foil packet that Sharpe fed to the robot. By varying the number of cells, their arrangement, and the electronics that control them, A123 can produce batteries with a wide range of sizes and electrical properties.

Versions as small as a six-pack of beer can power “micro-hybrids” whose engines shut off whenever the vehicle comes to a stop and start again when the driver touches the accelerator. In that scenario, the batteries provide bursts of power to restart the engine, and in some designs they can store energy from braking. Other battery packs as big as bookshelves store enough energy to allow electric delivery vans to complete their routes on battery power alone.

This year A123 will start manufacturing thousands of battery packs for six different vehicle models, beginning with the Navistar E-Star delivery van and the Fisker Automotive Karma—a full-size luxury sport sedan that uses electric power to boost acceleration and to power gas-free commutes. The company is also preparing to make batteries for two Chinese passenger vehicles, a medium-duty utility truck, and several micro-hybrids, and it’s making prototypes for dozens more vehicles.

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