RICHLAND, Wash. — A visit to the advanced battery team at the Pacific Northwest National Laboratory offers a glimpse into the future of electric car charging and an unplanned lesson in why that future needs to arrive sooner rather than later.
My wife and co-pilot, Marty Behr, and I arrived at PNNL just as the lab was announcing a big jump in developing a next generation lithium-metal battery. If perfected, it could double the driving range of a same-sized lithium-ion battery, according to Vince Sprenkle, technical group manager on the energy storage project at PNNL.
"The biggest challenge is the materials we use today will not get us there," said Sprenkle, the son of Missouri teachers with a doctorate in ceramic engineering. He joined PNNL in 2001 and holds 14 U.S. patents on fuel cells, batteries and a high-temperature electrochemical device. He has 22 more patents pending. PNNL named him inventor of the year in 2014.
Lithium metal would be the ideal material for building anodes, the negative posts inside car batteries. The critical hurdle turns out to be a rogue chemical reaction inside the battery that leads to the formation of a harmful growth called dendrites, or, more amusingly, "whiskers."
The whiskers consume the battery's electrolyte, which is the medium for transporting energy, and can lead to short circuits of the battery itself.
PNNL researchers using a specialized electron microscope and other prized research equipment have been able to observe how whiskers form, capturing the clumping of lithium on the anode until the moment when the whisker suddenly sprouts, like a stalagmite inside a cavern. In our recent visit, PNNL researcher Yang He showed off the microscope, a tower of chambers and electronic circuitry.
Capturing the whisker culprit in action has not solved how to stop it from happening; but it shows researchers where and how to look for the answers, Sprenkle said.
"How do I build that lithium anode so it will not grow whiskers? There's a lot of chemistry involved in how you do that," Sprenkle said.
"That is what the team is working on, how to solve those chemistry challenges that will enable a reusable lithium anode."
As a part of the Energy Department's Battery500 project, PNNL is advancing more rapidly thanks to coordinated research efforts across other DOE and university labs.
As we were briefed by Sprenkle and He, our electric Kia Niro was plugged in at a PNNL charging spot with what we hoped would be the primo charging experience on our leg of the road trip, from eastern Montana to Seattle. A bank of chargers was arrayed next to a big solar panel installation, promising carbon-free energy for most of the remainder of the trip.
For reasons unclear, the charger delivered no power. Despite the helpful efforts of PNNL staffers Nick Hennen and Shannon Bates, I had trouble logging on to the ChargePoint unit.
So we ended the day with less than 70 miles of range in the car, and 200 miles to go.
We scanned the online PlugShare map of public charging sites in the area and found a high-voltage direct current charger operated by Greenlots at a Starbucks near Walla Walla, Wash. Starbucks district manager Chris Cantlon said he was happy to recharge us and our car. The fast charger delivers 50 miles range in an hour roughly. The much more common "Level 2" charger, on a par with a home's 240-volt AC dryer outlet, would take eight or nine hours.
We'll need another fast charge to get over the Cascades. Here's to a future battery with twice the range as ours.