Makers Eye More Efficient, Less Costly Next-Gen Batteries
By William Diem
Aug 7, 2009 3:15 PM
TRAVERSE CITY, MI – The next generation of lithium-ion batteries could be coming from Sakti3, a spin-off start-up from the University of Michigan and General Motors Co. partner. The company, founded by U-M professor Ann Marie Sastry, is working on making solid-state batteries that could double the energy density of current cells.
Li-ion will be the chemistry of choice for the next two decades, say battery makers at the Center for Automotive Research’s 2009 Management Briefing Seminars, because you can’t go any higher on the atomic table except for hydrogen.
“Lithium is a low-atomic-mass material with a high voltage,” Sastry says, and new lithium technologies should be able to double energy density up to 140-220 Wh/kg.
High volume will drop the price of Li-ion batteries, because of economies of scale. At 400,000 hybrid vehicles a year, the price of Li-ion could fall below that of nickel-metal-hydride, the current choice of the Toyota Prius hybrid-electric vehicle.
For electric vehicles, the industry goal calls for battery costs of about $150 per kWh. Already, costs have come down by a factor of 14 in the past 15 years, says Compact Power Inc. CEO Prabhakar Patil. “They will come down more, but not as fast.”
His company, which will supply batteries for the Chevrolet Volt and other General Motors Co. HEVs, is building a plant that will go into operation in 2012 and could make up to 20 million cells a year.
Big advances in cost will come as battery makers take out non-energy weight. “Only 25% of the weight is storing energy,” says Ric Fulop, founder and vice president-business development at A123Systems Inc. The rest is the separator, electrolyte, various additions and packaging.
“There are so many approaches to increase energy density in Li-ion. Separators were 50 microns thick, now they are 10 microns.”
Taking 35%-50% of non-energy material out in the next decade will double the energy density of batteries and cut costs in half, he says. Working on new anode materials that will allow fast charging without sacrificing energy density also will improve current batteries, and a third area will be developing new manufacturing processes that are a lot more productive than current practices.
Cost will come out as volumes and business models change.
“Many of our suppliers operate at high margins,” Fulop says. “As volumes take off, there will be margin collapse.”
He says A123 is buying some of its suppliers to become more vertical and drive out cost.
In addition, big battery packs, like those for electric vehicles, are made with 16 kWh of power but use only 8 kWh because of cycling issues. If they were cycled all the way down in use, like current cell-phone and laptop-computer batteries, they would not last 10 years. But if improvements can be made on cycling, the same performance can come from smaller batteries.
Work on the next generation will increase rapidly because of federal grants designed to allow the U.S. to catch up with Asia on lithium battery technology. The U.S. had plenty of intellectual battery property, but manufacturing took off in Asia in the last decade because that is where most HEVs are produced. Federal support will bring cell manufacturing to the U.S., but the first projects will be battery-pack manufacturing.
GM will make the packs itself for the Chevrolet Volt, says Bob Kruse, executive director-global vehicle engineering for hybrids, electric vehicles and batteries.
“Our strategy is to be a smart cell buyer and a pack maker. Doing it ourselves controls the value chain.”
There are 150 parts in the Volt’s battery pack, he says, and all but eight were developed inside GM, which has decided battery development and manufacturing should be a core competence.
However, Kruse says some projects will be outsourced. The pack for the plug-in HEV Buick crossover will use the same LG Chem cells as the Volt but be manufactured by Compact Power in Michigan.
The battery industry already has many business models. A123Systems, a spin-off from the Massachusetts Institute of Technology, started making batteries for power tools and moved into products for the electric grid as well as developing batteries for the auto industry.
It has been a partner with GM, although it has no production contract yet, and is making batteries for Volvo Car.
Government grants are helping A123Systems, Compact Power, Johnson Controls-Saft Advanced Power Solutions LLC and the KD Advanced Battery consortium that includes Dow Chemical Co. to establish Li-ion cell manufacturing in Michigan.
“This hope of America becoming a leader in Li-ion batteries is being realized in Michigan,” Sastry says. But the future is always coming. “We will have to hurry.”
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