I recently read an interesting article in a Fast Company newsletter, sharing how engineers at Penn State University have come up with a new technique to dramatically increase the charge rate of electric vehicle batteries.
“We demonstrated that we can sufficiently charge an electrical vehicle in ten minutes to give a range of two to three hundred miles,” said Chao-Yang Wang, project lead and director of the Electrochemical Engine Centre at Penn State University. “We can do this maintaining 2,500 charging cycles, or the equivalent of half a million miles of travel.”
The new technique centres on heat. Up to now, charging rates have been limited due to degradation in lithium-ion batteries when charged at normal ambient temperatures. The research showed that deposits of lithium were forming on the battery anodes when charged at less than fifty degrees Celsius.
The researchers discouraged the plating by increasing the heat to sixty degrees C. At this temperature, batteries could be charged up to 2,500 times with no evidence of lithium plating. The same process tried at twenty degrees C showed huge degradation, with batteries showing significant deterioration due to plating after just sixty recharges.
Battery Charge Management
The symptoms seem close to the plating one finds on normal lead acid car batteries after standard charging on trickle chargers etc. Batteries left uncharged or on a low trickle charge for months can build up deposits of lead sulphate on the plates that permanently degrade the performance, with a marked increase in degradation in lower temperatures.
Owners can mitigate the effects of this plating by using battery chargers with charge management programmes, that vary the amount of voltage being fed into the battery. I have CTEK, Optimate and Facom smart chargers but there are plenty of others to choose from.
I got into using charge management devices when the kids were younger and I had an American motorhome/RV fitted with Elecsol carbon fibre leisure batteries. NLA nowadays, these batteries were efficient and lasted longer when maintained with a CTEK charger while the camper was stored between trips. Ambient temperatures had a noticeable impact on performance.
The current charge times for a 300-mile range on the typical EV are said to be about 50 minutes, meaning that Penn Sate has cut the charge rate by some 80%. The mind boggles as to what other developments across this technology may eventually be capable of bringing to EVs and the rest of our tech.