Following decades of research and a lengthy apprenticeship energizing our cell phones, laptops, and power tools, lithium-ion (Li-ion) batteries have begun closing the gap between today’s petroleum-fueled transportation and the electric cars of the future. Acknowledging this milestone on the road to more efficient automobiles, the Li-ion battery is Automobile Magazine’s 2010 Technology of the Year.
In the last decade, gasoline/electric hybrids have earned a secure foothold in the market, and the Tesla Roadster and the Mini E have taught us not to discount pure electrics as folly. The Chevrolet Volt, the Fisker Karma, and the Nissan Leaf will arrive later this year to further the electric-propulsion cause. These five cars and the Mercedes-Benz S400 Hybrid bear watching, because they’re the first vehicles equipped with Li-ion batteries.
The Feds support this movement. Tax credits will continue for those who curb their consumption by selecting a new high-efficiency vehicle. The Obama administration has also proposed raising the CAFE standard to 35.5 mpg in 2016, a 26 percent increase over last year’s fleet average. The most expeditious way to boost mileage while reducing emissions is to phase in more electric-drive systems. Enter the Li-ion battery – the great enabler for advanced hybrids and pioneering electrics. Li-ion batteries are significantly smaller and lighter than NiMH batteries (see chart), and they can be recharged overnight in homes equipped with suitable wiring.
As is the case with every new technology, there are issues. Li-ion batteries are vulnerable to overcharging, short circuits, and excess heat. A few of them caught fire doing laptop-computer service, and millions have been recalled to check for manufacturing defects. Longevity studies conducted by car and battery makers cannot predict exactly how long Li-ion batteries will last in consumers’ hands. Although it’s logical to expect that their cost will fall as their numbers increase, no one claims that Li-ion batteries will ever be cheap. Each Chevy Volt’s battery pack costs General Motors an estimated $10,000.
Elemental lithium is a highly reactive alkali metal located at the third position on the periodic table. This silver-white material is the lightest element that’s a solid at room temperature. Lithium’s willingness to release its outer electrons is what makes it an ideal battery constituent. Plentiful supplies of this material exist, too.
Michael Whittingham, now a professor at Binghamton University, first identified the potential of Li-ion batteries in the early 1970s. Research by John Goodenough at Oxford University enabled Sony to commercialize this breakthrough in 1991.
A dozen or so manufacturers are now preparing to mass-produce Li-ion batteries for automotive use. There are countless laboratories striving to increase the energy-storage capacity and reduce the cost of this better mousetrap. One anomaly: Honda and Toyota – the brands leading the green revolution – have been the slowest to endorse Li-ion batteries.