Powertrain & Energy - September 26, 2012 - 6

tech Report
Rethinking lead-acid for mild- and micro-hybrids
Thirteen years after Toyota and Honda launched the modern electrified-vehicle era with their Prius and Insight hybrids, the global market for HEVs and EVs remains miniscule compared with conventional ICE-powered vehicles. Even with an increasing number of nameplates from virtually every OEM (more than 40 as of 2012), Prius still accounts for the biggest slice of the segment, by far. No other hybrid or EV comes close. What’s the problem? Battery cost is still the primary hurdle to the widespread adoption of electrified vehicles, industry experts note. But the promise of better, less expensive battery technology has not come close to bearing fruit. In 1992 the U.S. Advanced Battery Consortium set a 10-year cost target of $150/kW·h for the “advanced” lithium-based solutions then emerging. At the time, nickel-metal-hydride packs of the size used in the original Prius were estimated to cost the OEM about $3500. Automakers targeted a cost reduction to $1400 per pack as needed to drive high-volume vehicle sales, but in 2012 the same pack is estimated to cost nearly $2000. “Despite huge technological advances made in nickel-metal-hydride and lithium-ion batteries and their processing in the past 21 years, the problem still is cost,” said advanced battery industry veteran Subash Dhar. “We can have a debate on what the real cost is for current hybrid and EV batteries, but in my view it is north of $700/kW·h. We need to be at $250/kW·h or less. That’s a factor of three.” Dhar, a chemical engineer, is founder and CEO of Energy Power Systems (EPS). The Troy, MI-based start-up is moving steadily down a technology path most others in the hybrid and EV battery industry had long abandoned: lead-acid. He is convinced there is a major opportunity for the world’s oldest, most ubiquitous battery chemistry that has provided safe and reliable energy storage since 1859. Energy Power Systems founder and CEO Subash Dhar spent years in lithium-ion development—and grew disenchanted with the industry’s ongoing claims about materials cost reduction. (Lindsay Brooke)

“What made me think about starting this company and focusing on lead-acid was my disenchantment with what I was hearing from the battery industry regarding lithium,” he told AEI. “People claiming 300-400 W·h/kg and that $150 kW·h was right around the corner. It doesn’t matter who says what, but I’d realized that NiMH and lithium battery costs are not coming down anytime soon. I thought something different is needed, that we can’t depend on these claims that keep getting repeated every 10 years.” Dhar said that though he applauds and supports the many development programs, he believes the auto industry must become “more pragmatic about what we can do during the next 10 years to reduce the battery burden on the vehicle. We can either use a smaller battery or reduce the cost of the battery by a factor of three or four.” To do that requires materials that provide four times the energy with about one-quarter the amount of material. That was Dhar’s focus while he was president of NiMH pioneer ECD-Ovonic Battery (from 1982-2003), then later vice chairman of EnerDel (and president of its parent, Ener1), and vice chairman of Envia. “Like everyone, I was chasing the dream of electric cars that go 250-300

September 26, 2012

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Powertrain & Energy - September 26, 2012

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