American battery maker A123 Systems announced a breakthrough in lithium-ion battery technology today. The company says its next-generation nanophosphate EXT batteries have two to three times the cycle life of other lithium-ion batteries and deliver full power over a wider temperature range.
The biggest challenge for electric cars and hybrids is battery technology. The batteries today are too big, too heavy, and too expensive. That's what limits electric cars to about 100 miles of range; you can't practically fit or afford batteries any bigger (and they'd take too long to charge anyway).
With today's automotive lithium-ion batteries warrantied for up to 10 years and 150,000 miles, battery life (as opposed to charge capacity) may not sound like a big issue. But with consumers' high expectations, and automakers' need to minimize warranty costs, automakers such as General Motors and Toyota have been installing batteries twice the size required to go the distance they expect. That means the batteries cost twice as much and weigh twice, as much as well. And they consume more space than necessary from passenger and cargo capacity.
Lithium-on chemistry causes batteries to start to deteriorate more rapidly as they get close to their fully charged and fully discharged states. So building bigger batteries with wider buffer zones on both ends, allows automakers to keep the battery cells within their optimal range and extend their lifespan.
This, improving the natural lifespan of battery cells, as A123 claims to have done, would allow hybrid and electric carmakers to reduce the cost and size of their batteries and bring down the cost of electric cars. Or, conversely, they could continue to install larger batteries, but use more of their capacity to gain range.
Longer-life batteries could also reduce potential replacement costs. And A123 says the new batteries will produce more power, as well.
Consumers could also benefit from extending the operating temperature range of lithium cells. When we tested the Chevrolet Volt and the Nissan Leaf in the winter, we found their range dropped almost in half. Better batteries could reduce the real-world limitation of that range penalty.
A123 supplies batteries for the Fisker Karma plug-in hybrid; it's batteries were the subject of a recall earlier this month. The battery pack in our Karma was replaced under warranty with less than 200 miles on the car. And A123 also won the contract to supply batteries for the upcoming Chevrolet Spark electric car.
We expect to see battery technology for electric cars to advance supplying more range, to deliver faster charging times, and to result in cheaper battery prices. Until we test cars with these next-generation nanophosphate batteries, we can't vouch for whether they live up to their claims. But we're hopeful the latest announcement represents such progress.