DOE study aims to improve EV driving range in low temperatures

Studies have shown that EV range can drop by as much as 40% when temperatures drop below 20°F and the heater is running. Tesla and others might dispute the exact amount of lost range, but there’s broad agreement that cold weather has a meaningful impact. That challenge led the US Department of Energy’s Office of Energy Efficiency and Renewable Energy to award $480,000 to Professor Brett Lucht to study how to improve battery performance in low temperatures.

Lucht, a chemistry professor at the University of Rhode Island, is undertaking a three-year study as a sub-contract from Brookhaven National Laboratory. Lucht said:

The performance of batteries at low temperatures, especially for charging, is one of the major issues for the automotive industry. People living in Wisconsin and Minnesota want their electric vehicles to function when it’s negative-10 degrees outside.

And if you’re living in Florida, you may want to drive up and see your family in New Jersey in the winter. Even if you’re not immediately affected, it can create doubt about whether the vehicle is going to perform.

Lucht is focusing on the electrolyte liquid in lithium-ion batteries and its interaction with the positive and negative electrodes. The electrolyte is the medium between cathode and electrode that ions travel across when the battery charges and discharges.

The electrolyte is also the focus of work based on findings by Nobel laureate John Goodenough. His research could one day lead to a 500-mile, affordable EV battery. However, Lucht is focusing on the more immediate issue of maintaining range in frigid temperatures. There are also detrimental impacts from low temperatures for quick charging.

Lucht said:

The conductivity of the liquid electrolyte decreases with decreasing temperatures. In addition, the resistance of the interface between the electrode and the liquid increases. So, basically, it is harder for the lithium ions to go back and forth.

We’re trying to understand the cause of the poor performance and then systematically design better electrolytes and interfaces between the electrolyte and the electrodes to address the problem.

Lucht is currently working on a two-year, $720,000 contract with the US Advanced Battery Consortium, a collaborative organization of FCA, Ford, and General Motors.

He previously studied low-temperature performance in the batteries for military aircraft in Alaska. He has worked with government agencies such as the Department of Defense and the National Science Foundation and private corporations, including DuPont, Procter & Gamble, Duracell, BASF, and Samsung.

For Professor Lucht, his projects on cold-weather EV battery operations are not just academic exercises. It’s a mission. He said:

I think the green economy is an important thing for our country and our state. Batteries are a very important contribution, both in the sense of consumer electronics, electric vehicles, and in renewable energy. For me personally, I get a lot of enjoyment from working in an area that benefits both our local economy and the world as a whole.