WASHINGTON – Scientists in the U.S. have claimed a technological breakthrough that could resolve one of the key concerns surrounding all-electric vehicles, saying just 10 minutes of charging time could add 200 miles (320 km) of driving range.
Writing in the journal Joule on Wednesday, researchers at Pennsylvania State University said that such a speedy charge rate required a battery to rapidly take in 400 kilowatts of energy.
Current-generation vehicles are not capable of this feat because it risks lithium plating — the formation of metallic lithium around the anode — which would severely deteriorate battery life.
To get around this constraint, the researchers raised the temperature of their experimental battery to 60 degrees Celsius (140 Fahrenheit) during the charge cycle, then lowered it back down as it was used.
What this does is “limit the battery’s exposure to the elevated charge temperature, thus generating a very long cycle life,” said senior author Chao-Yang Wang, a mechanical engineer at The Pennsylvania State University.
But scaling up the design and bringing it to market may take a decade, said Rick Sachleben, a member of the American Chemical Society.
Makers will need to make sure that rapidly raising the temperature is safe and stable, and doesn’t lead to explosions given the phenomenal amount of energy that is being transferred.
“Fast charging is one of the holy grails of electric vehicles,” he said. “It’s one of the things that is necessary for them to compete with petroleum-fueled internal combustion engines.”
The current generation of Tesla vehicles require about 30 minutes for a partial charge.
One of the inventors of rechargeable lithium-ion batteries who was awarded a Nobel Prize in chemistry in October, M. Stanley Whittingham, says ongoing research will continue to make the batteries cheaper, safer and with greater energy density.
Further improvements to the technology may also bolster efforts to combat climate change by enabling greater use of renewable-energy sources, he said.
He said lithium-ion batteries will continue to dominate in smartphones and electric vehicles for at least the next 10 years “because there is nothing really on the horizon,” though Toyota Motor Corp. and American companies are working on solid-state batteries. It’s not clear yet whether you’ll get a decent amount of power” from such batteries, he added. “They may work for things like iPhones initially, but there are some big questions before they are used in larger-scale systems.
Still, Whittingham said, “If you look at the sellers of electricity, they don’t particularly want them to be charged very fast.”