Ford & Purdue Develop a Patent-Pending Liquid Cooled EV Charging Cable for Rapid Recharging

author: FutureCar Staff    

One of the roadblocks to the widespread adoption of electric vehicles is finding convenient charging stations, as well as the extra time its takes for some vehicles to reach a full charge. Although automakers are beginning to introduce electric vehicles that accept higher charging rates that can reduce charging times to around 20 minutes, that's still considered too long for many drivers.

To address this issue, Ford Motor Co and researchers at Purdue University have been working on new types of charging cable that might be able to charge an EV in just minutes.

Researchers from both groups are working to develop a new, patent-pending charging station cable that could combine with new vehicle charging technology to significantly reduce EV charging times, which can help more drivers transition to EVs. 

The main problem the two groups are addressing is a new cooling method that allows for higher current, without the risk of overheating the cable or the vehicle's batteries. The cable itself is liquid-cooled, which can help dissipate more heat created while the vehicle is plugged in and charging. 

What's unique about the built-in cable cooling system is that the coolant turns from liquid to gas during the changing phase to further dissipate heat. Its similar to how an air conditioning system works, with refrigerants turning from liquid to gas to remove heat to cool a room. The result is a cable that can accept higher charging currents, which translates into faster charging times.

Liquid cooled cables are already in use by EV charging operators like Electrify America to prevent charging cables from overheating, but the one developed by Ford and Purdue takes its a step further converting the liquid to a gas to greatly improve cooling performance. 

"Today, chargers are limited in how quickly they can charge an EV's battery due to the danger of overheating. Charging faster requires more current to travel through the charging cable," said Michael Degner, senior technical leader, Ford Research and Advanced Engineering. "The higher the current, the greater the amount of heat that has to be removed to keep the cable operational."

Ford says that this charging cable design may one day deliver significantly more power than today's leading systems to re-charge electric vehicles, making the potential of faster re-charging times possible. However the technology's full potential won't be realized unless vehicle charging and other technology enhancements are made in parallel. 

This could eventually lead to re-charging EVs as quickly as conventional gas station fill-ups, according to Ford.

The idea for this technology originated based on the Ford team's understanding of the challenges faced of increasing charging rates with higher current, as well as Purdue researchers' area of expertise. The teams collaborate regularly to review the latest results and give feedback on areas of focus as the technology is developed.

"Electric vehicle charging time can vary widely, from 20 minutes at a station to hours on an at-home charging station, and that can be a source of anxiety for people who are considering buying an electric vehicle," said Issam Mudawar, Betty Ruth and Milton B. Hollander Family professor of mechanical engineering, Purdue University. "My lab has come up with a solution for situations where the amounts of heat that are produced are beyond the capabilities of today's technologies."

Mudawar has been developing ways to more efficiently cool electronics for the past 37 years by taking advantage of how liquid captures heat when boiled into a vapor. While the fast-charging cable won't be on the market for some time as research continues, he says his lab at Purdue intends to begin testing a prototype charging cable in the next two years to determine more specific charge speeds for certain models of EVs.

"Ford is committed to making the transition to electrification easy," said Degner. "We are glad to work closely with Purdue's research team, which has the potential to make electric vehicle and commercial fleet ownership even more appealing and accessible."

The alliance between Ford and Purdue provides graduate students with opportunities to work on real world-challenges helps them develop their skills. At the same time, projects like this one introduce students to Ford and its research on new technologies, which can help the automaker attract new talent as its shifts to building more electric vehicles powered by software.

FutureCar Staff