Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering (right),
and postdoctoral research associate Mohammad Asadi with their specially modified
differential electrochemical mass spectrometry (DEMS) instrument.
PHOTO CREDIT: UIC College of Engineering
(January 20, 2016) Lithium-air batteries hold the promise of storing electricity at up to five times the energy density of today’s familiar lithium-ion batteries, but they have inherent shortcomings. Researchers at the University of Illinois at Chicago have helped prove that a new prototype is powered by a surprising chemical reaction that may solve the new battery’s biggest drawback.
The findings are reported in the Jan. 11 issue of Nature.
Today’s lithium-air batteries (in which the metallic lithium of the anode, or positive terminal, reacts with oxygen from the air) hold great promise, because they store energy in the form of chemical bonds of oxide compounds. Versions tested to date have stored and released energy from lithium peroxide, an insoluble substance that clogs the battery’s electrode.
Battery scientists at the U.S. Department of Energy’s Argonne National Laboratory developed a prototype that they claimed had the surprising ability to produce only lithium’s superoxide, not peroxide, as the battery discharges. Unlike troublesome lithium peroxide, lithium superoxide easily breaks down again into lithium and oxygen, thus offering the possibility of a battery with high efficiency and good cycle life.
The Argonne group designed the battery to consume one electron rather than two and produce the superoxide, said UIC’s Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering. But it was difficult to prove the reaction took place.
“Ex-situ analysis is not accurate enough to prove such a big claim,” he said.