Charging Up That Hill

Beyond committed environmentalists and hardy early adopters, the rest of the nation may be less tolerant of battery-related EV inconveniences. At least that’s the fear of government agencies and nonprofits behind a sweeping plan to “decarbonize” the U.S. economy to save the planet from global warming—and it’s why UMD researchers are at the forefront of developing EVs that can charge faster than you can fill a gas tank, have the range to cruise to the horizon and beyond without a stop, and boast unprecedented safety and performance in even the most extreme conditions.

The clock is ticking. Limiting U.S. greenhouse gas emissions to head off the worst effects of climate change means getting as many butts in electric vehicle seats as possible and moving to a power grid based on renewable energy sources, including wind, solar and hydrogen fuel.

“We have to accelerate the societal shift to electric vehicles,” says Distinguished University Professor Eric Wachsman, a globally recognized expert in next-gen battery technologies and director of the Maryland Energy Innovation Institute. “And that means you have to overcome the resistance some people have to these kinds of vehicles.”

As anyone knows who’s seen surveillance videos of exploding scooters and terrorized vape pen users dropping and fleeing their devices, or discovered their phone bulging and nonfunctional with a swollen battery, lithium-ion cells have a dark side that stems from their chemistry. They use
a flammable liquid electrolyte, the part of the battery that carries electric current between the positively and negatively charged internal components of cells, made of lithium salts dissolved in an organic solvent.

“Liquid lithium electrolytes are very volatile. If you have a short or damage to the battery, you can have what’s called a thermal runaway reaction where the battery’s energy heats up the battery uncontrollably and can start a fire,” says Professor Chunsheng Wang, director of UMD’s Center for Research in Extreme Batteries—a collaboration with the U.S. Army Research Lab—and like Wachsman, a faculty member in chemical and biomolecular engineering as well as in materials science and engineering.

(For perspective, EVs don’t burn often, although they get a lot of press when they do. “They’re very safe, safer than a typical car, in fact,” says Ron Kaltenbaugh, president of the Electric Vehicle Association of Greater Washington. His claim echoes recent data from both Tesla and an Australian government study showing that EV batteries, frequently bundles of hundreds of smaller battery cells, are an order of magnitude less likely to ignite than petroleum-powered engines. “But they can be pretty hard to put out” once fully engulfed, Kaltenbaugh says.)

Managing conventional lithium-ion batteries’ safety issues comes at a heavy cost—literally. Their various added layers and separators, along with extra circuitry and other protection measures on the outside, make current EV battery systems far bulkier and less “energy-dense” than they would be with inherently safer chemistry.

Issues of vehicle range, charging rates and infrastructure are interrelated; one way to incentivize building more charging infrastructure is to make more people want—and buy—electric cars by addressing the issues in a holistic manner rather than individually. UMD’s battery experts plan to do that in part by rendering obsolete one of the loudest complaints against EVs: They take too long to charge.

While “slow” is relative, so-called Level 1 charging with regular outlets is painfully poky, adding less than five miles of driving range for every hour plugged in. Level 2, available at around 54,000 public charging stations in the U.S. and at many EV drivers’ homes, uses 240-volt power to add 20 or more miles of range an hour. Level 3, known as DC fast charging, or “Supercharging” in the Tesla universe, can boost a car’s battery to 80% in 20 minutes to an hour. The catch? Only about 9,400 such charging stations exist in the United States, according to research by UMD’s Center for Global Sustainability (CGS), and per mile they rival gasoline in cost, negating one of the draws of EVs.

That scarcity leaves vast swaths of the population without a practical way to drive an EV, contributing to sluggish sales even as average prices have been plummeting. CGS’s work found that access to charging is far from equal in U.S. society, with members of racial and ethnic minority groups and low-income people on average traveling farther to find an EV charger, says Jiehong Lou, a CGS assistant research professor who studies equitable access to EV technology. Likewise, African Americans have less potential to reap the cost savings of home charging because of significantly lower homeownership rates than white people, she says.

To be broadly popular, EVs can’t require a hobbyist level of commitment and a spacious suburban home, Wachsman says.

“Someone like me can drive home at night, close the garage door when it’s cold outside (because EVs don’t charge well in the cold), plug into a Level 2 charger, and you’re ready to drive the next day,” says Wachsman, who’s driven a Tesla since 2013. “But there are a lot of people who live in apartments, live in a city environment, who just don’t have home charging. Then it gets a lot harder to drive an EV.”

“Electric vehicle technology is never going to ‘get there’ if that means a stage where it’s fully developed,” says Kaltenbaugh, whose family has transitioned entirely to battery-powered cars. An avid skier, he’s seen the impact of climate change in mountain environments around the country, where subtle temperature changes can have outsize impacts on snowpacks.

“It’s going to keep developing. It’s a matter of whether the price-to-performance ratio works for you. If it does, you get an EV.”

For those who can afford a new car now and have a place to charge it, EVs’ efficiency and performance advantages combined with lower regular maintenance requirements already make them a logical choice over fossil fuel-powered vehicles, says Wachsman. With their revolutionary battery advances, Maryland researchers plan to soon push it over the hump for everyone else.—TERP