Battery breakthrough could be game changer

Source: John Fialka, E&E News reporter • Posted: Wednesday, April 4, 2018

Scientists have developed a prototype battery for electric cars that promises to be cheaper and more powerful than the currently used lithium-ion batteries.

The new devices result from an engineering breakthrough that allows magnesium metal to be used, which may also result in safer batteries that don’t overheat, the Department of Energy’s National Renewable Energy Laboratory (NREL) in Golden, Colo., announced yesterday. The development is a potential game changer, allowing lighter and more efficient electric cars.

The announcement came on the same day that U.S. EPA Administrator Scott Pruitt officially announced that the Trump administration plans to lower efficiency and emissions standards for passenger vehicles. A new battery that promotes cheaper, cleaner cars and light trucks could introduce a wild card into the race to develop and sell cleaner technologies to compete with fossil-fueled sport utility vehicles.

The technology breakthrough came after a struggle by scientists to find a way to recharge magnesium batteries, a goal that had been blocked by severe corrosion problems in the electrolytes of test batteries as they came into contact with the magnesium.

But the recharging problem was overcome by using polyacrylonitrile, a vinyl-like material that is used for a variety of products, including knitted clothing, sails for sailboats and fibers for reinforced concrete, according to NREL. The material, combined with a magnesium-ion salt, “markedly improved” battery recharge performance.

The use of magnesium, which is more plentiful than lithium, allows batteries that can produce twice as much electricity as lithium-ion batteries and, according to NREL, eliminates the growth of dendrites, or crystals that made some lithium-ion batteries overheat because the crystals grew and created short circuits inside the batteries.

“Being scientists, we’re always thinking: What’s next?” said Chunmei Ban, a scientist in NREL’s materials science department and a co-author of a paper on the development, which was published in the journal Nature Chemistry.

She noted that because lithium-ion batteries appear to be approaching their limits in terms of energy production and storage in a given volume of space, “there is an urgent need to explore new battery chemistries.”

According to NREL, the recharging breakthrough allowed a team of scientists to produce prototype cells that proved to be robust, using a process that had “never been demonstrated before” to reduce both corrosion and limitations on electricity production.

Other researchers involved with the project came from the University of Maryland, the Colorado School of Mines and the U.S. Army Research Laboratory.