In a new report published on 30 October 2019, researchers from Penn State University detail a new lithium ion battery design that could allow electric vehicles (EVCs) to be charged within 10 minutes, giving roughly 200 miles (320 kilometres) a pop without reducing the battery’s lifespan.
Slow charging has been the bane of electric vehicles for decades now, with even the most advanced stations providing no more than 60-80 miles (96–128 kilometres) of additional range per hour, making the technology seem like a science fiction pipe dream.
The lack of progress in this area is mostly down to lithium plating, which refers to the process where a large amount of incoming energy forces lithium ions to move at a faster rate of reaction and accumulate on the surface of the anode, thereby damaging the battery.
By deploying a method called Asymmetric Temperature Modulation, the researchers were able to heat up a lithium ion battery to a constant 60 degrees Celsius (140°F) during charging, and then discharge it at cooler temperatures.
This allowed them to charge large-scale cells, modules, and battery packs used in today’s EVCs to 80% of their full capacity in under ten minutes, which brings the dream of closing the gap between EVC charging and filling up a fuel tank a great deal closer to reality.
The key to success here was inexpensive self-heating nickel foil which enabled the necessary heating to take place in approximately 30 seconds. High temperatures halt the development of lithium plating, but also speed up the degradation of the battery itself.
In this case, however, the batteries were found to retain as many as 91.7% of their capacity after 2,500 charge cycles – all thanks to the heat being jacked up for no more than 10 minutes per charge.
To make EVCs a common sight on the road, engineers will still have to figure out a way to ensure adequate heating under varying environmental conditions. Furthermore, new fast-charging infrastructure would have to be deployed all around the world, and the batteries would have to be standardised to include a nickel foil heating element.
All significant challenges, no doubt, yet as the technology is rolled out, market forces will likely take care of them without too severe of a struggle.
The paper is available in the journal Joule.