Anyone who has an interest in electric vehicles (EVs) knows the common knocks against them by heart: long charging times, limited range, charging station availability, and so on. To make the EV more palatable to the American public, researchers at Penn State University have had a breakthrough — reducing lithium-ion battery charging times to 10 minutes.
Lead author Xiao-Guang Yang and his colleagues published a report in Joule, a journal focused on the science of sustainable energy. There are still some hurdles to clear but the long-held dream of a practical EV on par with the convenience of a gasoline engine could be closer at hand than people think.
In a home with standard 120 Volt electrical outlets, you’ll get about two to five miles of range per hour, while charging through a more powerful 240 Volt outlet delivers ten to twenty miles per hour of charging. Currently, fast-charging stations are much quicker but can take twenty minutes to provide just 60-80 miles of additional range. Faster charging hasn’t been able to progress due to the damaging effects of lithium plating (metallic lithium that forms around the anode of the battery) which forms when a lot of electricity is delivered very quickly.
The key to solving this problem, according to the paper, is rapidly heating the battery to 140 degrees Fahrenheit (60 degrees Celsius) in 30 seconds and maintaining that temperature during the charging cycle. The solution came in the form of an inexpensive nickel foil installed on the batteries. Operating at higher temperatures for only a short time, in this case 10 minutes, prevents the formation of lithium plating.
With this system in place, the team found that after an astounding 2,500 charging cycles, their battery still had 91.7% capacity. That equals half a million miles in driving distance with hardly any more time involved in charging than it takes to refuel a gasoline-powered vehicle.
Still, hurdles remain before this can get out to the general public. For starters, getting the battery up to temperature and stabilizing it there raises environmental concerns. If the batteries get too hot, they can degrade or in rare instances, explode. But if they are too cold, lithium plating will occur.
Another issue is that a new type of fast charging station would be needed, or existing ones upgraded. Finally, all battery manufacturers would have to standardize nickel foil plating into their designs. It is not unreasonable, though, to think that these could be solved in a reasonable amount of time given the fast-paced technology being developed today.
