Chibueze Amanchukwu

Today, nearly all electronics and electric vehicles are powered by lithium-ion batteries. They work by shuttling charged particles, or ions, between a metal cathode and an anode typically made of graphite. Researchers have known for decades that an anode made from lithium, the lightest metal on the periodic table, could enable a rechargeable battery to store significantly more energy relative to its size. But lithium is highly reactive: Interactions with the battery’s electrolyte, which usually consists of a salt dissolved in a volatile liquid solvent, make lithium metal batteries more prone to catching fire. Researchers have sought to overcome this hazard by replacing liquid electrolytes with solids, but that reduces  performance.

Chibueze Amanchukwu, 31, developed a new type of electrolyte that’s a liquid when the battery is in use and is free of any fire-causing solvents. The process involved months of testing different combinations of salts to find a concoction with a low enough melting point. His team’s electrolyte, made from a mix of lithium, potassium, and cesium, melts at 45 °C—meaning it could work in batteries built to power EVs or to store grid electricity. The researchers are now working to push that temperature as close to 0 °C as possible.

The technology, Amanchukwu says, is not quite ready for commercialization. But it marks a major step toward what he calls the “elusive dream” of making lithium metal chemistry work. “What our work shows is that you can have batteries with high energy density and high performance, without sacrificing safety,” he says.