Researchers all over the world are exploring electric vehicle batteries that would go farther and weigh less, and one such concept — lithium-air batteries — has a reached a major milestone. A US research team has proven that lithium air batteries, which could offer up to four times more energy density versus today’s commonly used lithium-ion batteries, can work successfully in a laboratory setting at a very small scale. For electric vehicles, a fourfold energy density boost would mean ranges of 1,000 miles (1,600 kilometers) per charge, roughly speaking, which would go a long way to easing consumer range anxieties.
“Right now the batteries are the size of a dime. They have to be scaled up maybe 50 to 100 times. That’s the next step in this work,” says team co-leader Larry Curtiss of the US government’s Argonne National Laboratory, which is researching the batteries in partnership with Mohammad Asadi at the Illinois Institute of Technology. The team will now work to ensure that important aspects of the battery, like air flow and charging, can work as well as they did in the lab at a real-life scale — which won’t be easy. “It’s a different architecture because it’s much larger,” Curtiss tells Energy Intelligence in an interview.
Lithium-air batteries use solid-state electrolytes and a reaction of lithium ions with oxygen, instead of liquid electrolytes used typically today, explains Curtiss. “We were the first ones that have been able to develop a solid-state electrolye for a lithium air battery that works.”
Aside from the higher energy density, the technology would also be much safer, he adds. Liquid electrolytes used in lithium-ion batteries can overheat and catch fire, whereas the solid-state electrolytes avoid this.
Although lithium-air batteries would of course use lithium, they require no cobalt, which is a “big drawback” with lithium-ion batteries, Curtiss says. Ideally, lithium recycling capacity will ramp up and cut back on the demand for new lithium, he adds.
Planes, Ships, Trucks
The limited energy density of lithium-ion batteries is particularly problematic for sectors like aviation, shipping and long-haul trucking that need a lot of energy without having to add significant weight. In aviation, which cannot be feasibly decarbonized using lithium-ion batteries because of the weight issue, studies show that lithium air or other solid-state batteries could enable flights of up to 1,000 miles. This could include, for example, flights traveling within the mainland US between some states — although the range depends on how the planes would be used, Curtiss says.
Advanced battery chemistries are a highly prized space, both from a commercial standpoint to improve the selling points of electric vehicles, but also a geopolitical standpoint given the concerns about mineral dependence. This political motivation has grown more intense due to the Russia-Ukraine war and the pandemic-related supply chain problems seen in China.
Next-generation battery frontiers are numerous. Argonne and Illinois Institute of Technology researchers are also exploring sodium-air battery technology, which is not as far along as the lithium-air concept, but would involve no lithium or cobalt, Curtiss explains. Unlike those elements, sodium is common and widespread. In a similar vein, research is also under way by start-up companies on batteries based on sulfur, another easy-to-find element. And, notably, many versions of solid-state battery technologies are being researched, including by players like Toyota.
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