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Materials Matter
In early 2001, a 26-year-old Venezuelan entrepreneur named Ric Fulop walked into the office of Yet-Ming Chiang, a professor of materials science at MIT, without an appointment. “He just showed up and knocked on the door,” recalls Chiang. Fulop, who had already founded three venture­-backed companies, wanted help starting a battery company, and he knew that Chiang was conducting battery research involving nanotechnology. Chiang himself had cofounded a successful startup in the late 1980s, but he spent most of his time researching nanotechnology and the chemistry of advanced ceramics.

By the fall, Fulop and Chiang, along with Bart Riley, an engineer Chiang knew from his previous venture, had cofounded A123 Systems. The plan was to commercialize one of Chiang’s more radical ideas: materials that, when stirred together, would spontaneously assemble to form a working battery. The process promised to multiply energy storage capacity while lowering manufacturing costs.

Chiang’s big idea turned out to be a hit with investors. By the end of 2001, a first round of funding had brought in $8.3 million from various venture capital firms. Motorola and Qualcomm, intrigued by the prospect of better batteries for portable electronics, soon added $4 million. But it quickly became clear that a commercial self-assembling battery was years away from reality. The technology “was still pretty rudimentary,” Chiang says.

In early 2002, however, Chiang made a surprising discovery that would completely change the company’s direction. He had begun to work with lithium iron phosphate, which is nontoxic, safe, and inexpensive, unlike the materials used in other lithium-ion batteries. But it appeared to have some serious drawbacks. It stores less energy than lithium cobalt oxide, the electrode material in conventional lithium-ion batteries, so it seemed unsuitable for use in portable electronics, where energy storage is paramount. Also, it charges and discharges slowly, ruling out its use in high-power applications such as hybrid electric vehicles; even for fully electric cars, which use many more battery cells than hybrids, the material couldn’t deliver enough power.

So Chiang started to modify it by adding trace amounts of metals. Soon the material was discharging power at relatively high rates. In mid-2002, he flew to Monterey, CA, to present his findings at a conference. While he was there, a graduate student back at MIT continued running tests. By the time ­Chiang was scheduled to talk, the material was performing at rates four times those he had come to announce. “At that point, we knew we had something special,” he says.

Eventually, Chiang would demonstrate that the material could deliver bursts of electricity at 10 times the rate of those used in conventional lithium-ion batteries. After studying the high-­performing material in detail, he determined that it owed its power both to the size of the particles he’d used (less than 100 nanometers) and to the addition of the extra metals. The combination of those factors, he says, causes a fundamental difference in the way the atoms that make up the material rearrange themselves when they receive and release a charge.

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Credits: Porter Gifford, Courtesy of General Motors

Tagged: Energy, energy, batteries, electric cars, A123 Systems, GM, lithium-ion, A123, hybrid engine

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