Lithium-Ion Batteries Fuel the Future of Automotive Design

In 1924, General Motors president Alfred P. Sloan Jr. devised annual model-year design changes in order to maintain unit sales. Body shapes faced cosmetic changes every year, whether or not the underlying automobile had changed. This breakthrough strategy had widespread effects on the automobile business, automotive design, and eventually the United States economy. In recent years, amongst a worsening economy and a struggling auto industry, the underlying automobile has changed rapidly, with emphases on efficiency and environmental friendliness. As industrialized nations begin to devote serious attention to lessening dependence on oil and at improving emissions, the electrification of the automobile is a very real solution.

Market researchers expect the sales figures for battery-operated vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicles (EVs) to climb steeply. More than 75 hybrid models will hit the market by 2011, and it is the Obama administration’s goal to put one million American-built PHEVs on the road by 2015. Several companies, including Chrysler, Mercedes-Benz, Mitsubishi, Toyota, and Smart, showed experimental electric cars at this year’s North American International Auto Show.

GM’s Chevy Volt Plug-In Hybrid electric vehicle uses lithium-ion cells in the vehicle’s 16-kWh battery pack.
The main battery technologies that are potentially viable for HEVs, PHEVs, and EVs are lead-acid (Pb), nickel metal hydride (NiMH), and lithium-ion (Li-ion). Lithium is the lightest metal, with properties unique in terms of energy and power density, and it is mined in parts of South America, Canada, Australia, and Tibet. NiMH technology is presently the presiding battery application for HEVs, but the market is shifting to Li-ion due to its size, weight, performance, and cost advantages.

Purely electric vehicles are the most environmentally friendly out of the three battery-powered vehicles. EVs offer several advantages, such as zero tailpipe emissions, overnight battery recharging, and the use of cleaner energy produced through advanced natural gas and coal gasification technologies. Electric vehicles also offer energy security by replacing imported petroleum with domestically generated electricity. Yet the American auto industry still faces challenges from foreign competition in batteries. Until the battery-operated automotive market launched, there were no large markets in the US to sustain Liion battery manufacturing. The extensive amount of consumer electronics products that use lithium-ion batteries, such as laptops and cell phones, are manufactured in Asia.

Producing Li-ion Batteries in the US

Although General Motors (GM) will build its own battery packs for their Chevrolet Volt PHEVs, the company will continue to buy battery cells from outside suppliers. GM’s executive director of North American Engineering Operations, Bob Kruse, said that this is because developing new electrode chemistries and manufacturing the cells themselves requires expensive equipment. LG Chem, a company based in Korea, is currently supplying the Li-ion batteries for the Volt. Hundreds of lithium- ion cells must be wired together and paired with control electronics to create the Volt’s 16-kilowatt-hour battery pack. Kruse added that GM’s plan to make batteries is similar to the company’s decision to make its own engines, in that the technology is vital to the company’s future success. General Motors is one of many companies using foreign-produced lithium-ion battery technology in their battery-operated vehicles.

Leading US battery and advanced materials companies have joined together to form the National Alliance for Advanced Transportation Battery Cell Manufacture to manufacture advanced lithium-ion battery cells for transportation applications within the United States. The founding members of the Alliance include 3M, ActaCell, All Cell Technologies, Altair Nanotechnologies, Dontech Global, EaglePicher Corporation, EnerSys, Envia Systems, FMC, MicroSun Technologies, Mobius Power, SiLyte, Superior Graphite, and Townsend Advanced Energy, with additional battery developers and materials suppliers expected to join. The US Department of Energy’s Argonne National Laboratory in Argonne, IL — a national research laboratory and leading developer of new battery technologies — has been active in encouraging the Alliance and serves in an advisory role as the Alliance begins operations.

The Alliance plans to develop at least one manufacturing and prototype development center in the US, to be shared by Alliance members. Developing the capability to mass-manufacture advanced battery cells is expected to require an investment of $1 to $2 billion over five years, most of which is anticipated to come from the federal government. Alan Elshafei, CEO and founder of MicroSun Technologies, stated that, “For 20 years, the United States has sat idly and watched foreign markets become the leaders in lithium-ion technology. I am excited by the prospects of creating this collaboration to concentrate the educational and manufacturing resources within the United States to create safer, more powerful battery cells for our markets.”

Along with advising the National Alliance for Advanced Transportation Battery Cell Manufacture, Argonne National Laboratory has teamed with a research partner, EnerDel (www.enerdel.com), a subsidiary of Ener1, the first company to commit to producing advanced lithium-ion batteries in the US on a commercial scale for the automotive market. “Whether it is a plug-in hybrid like the Chevy Volt or a fully electric car like the Th!nk City, the future depends on better batteries,” Ener1 CEO Charles Gassenheimer said. Ener1 currently has the only USbased, large-scale lithium-ion manufacturing facility for automotive applications. The Indiana manufacturing facility will be able to produce more than 300,000 HEV packs per year. Ener1 has also recently purchased an 85% stake in Enertech In ter - national, one of South Korea’s leading lithium-ion battery cell producers. The company’s plants in the US and Asia will have the capability to produce battery packs for approximately 45,000 EVs, or 450,000 HEVs.

EnerDel/Argonne Battery Performance

The EnerDel/Argonne Advanced High-Power Battery is a highly reliable and safe device that is lighter in weight, more compact, more powerful, and longer-lasting than NiMH batteries in current HEVs. EnerDel employs a high-power chemistry and a high-energy- density chemistry, which are tailored to different applications. The high-power chemistry is used in HEVs, and the high-energy- density chemistry uses a hard carbon and mixed oxide combination that is suitable for PHEVs and EVs. The company’s lithium-ion cells have a prismatic design instead of the conventional cylindrical model, allowing for potentially higher energy density levels. The larger surface area of the prismatic design dissipates heat and increases the number of cooling options in the automobile, and its shape makes it easier to assemble into modules. This, in turn, cuts production time and increases production capacity.

Th!nk electric vehicles using EnerDel lithium-ion batteries are currently in production. The batteries allow a range of 180 km and a capacity of 26 kWh.
The battery does not use graphite as the anode material, which has been a safety concern regarding other Li-ion battery types. Argonne developed a nanophase form of stable lithium titanate (LTO) to replace the graphite, along with the process for making this form of nanophased LTO. The new form of nanophase LTO will allow for easier industrial processing, and provide a high packing density that can supply the power needed for vehicle acceleration and regenerative charging of HEVs. Argonne had also previously demonstrated that their composite electrode structures have advantages over conventional lithium-ion battery electrodes in terms of their structural, electrochemical, and thermal properties. “Our technology is precisely what is needed to enable a timely switch from a fossil-fuel economy to an economy that relies on alternative energy sources,” said Argonne researcher Michael Thackeray.

The battery system is designed to accommodate an additional cooling system if required, but the thermal performance of EnerDel’s chemistry indicates that vehicles can use their existing air cooling system without the need for a separate liquid cooling system. A separate system can impede the weight, design, and cost of the vehicle. During testing, the lithium-ion cells retained over 95% of their initial capacity after 1,000 charge and discharge cycles. EnerDel has recently and successfully demonstrated the integration of a lithium- ion battery pack in a Toyota Prius HEV. The integration was later tested by Argonne. The Norwegian company Th!nk Global has already taken delivery of prototype battery packs and these packs were successfully integrated into functional EVs. Th!nk electric vehicles equipped with EnerDel’s battery pack are expected to be commercially available in 2010.

The Future

With government support, lithium-ion batteries could be a successful technology targeted at helping the auto industry and the environment. The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy’s (EERE) FreedomCAR and Vehicle Technologies program provides funding for Argonne’s battery research. EnerDel has recently applied for $480 million in low-interest loans under the Advanced Technology Vehicle Manufacturing Incentive Program (ATVMIP), which is administered by DOE. The $25 billion program is designed to enable US auto companies and their suppliers to build or retool manufacturing facilities for the improvement of the overall corporate average fuel economy of the American automotive industry.

A123 Systems (www.a123systems.com) is another US-based developer and manufacturer of advanced lithium-ion batteries for the transportation market. The Watertown, MA-based company recently submitted an application under the ATVMIP to qualify for $1.84 billion in direct loans to support the construction of lithium-ion battery manufacturing facilities in the US. The first construction location would be in Michigan.

Funds from DOE could enable EnerDel to double manufacturing cap - acity to produce 600,000 HEV packs per year at its existing plant by 2011, and to build a second larger plant capable of producing battery packs for up to 1.2 million hybrid electric vehicles by 2015. Utilizing DOE data, Ener1 estimates that batteries produced at these facilities each year could save the US economy as much as $600 million at the gas pump, and eliminate up to one billion tons of carbon emissions annually.

For more information, visit Argonne National Lab here.

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