“Others have tried to build lithium-air battery cells that run on air, but they failed because of little cycle life,” said Larry Curtiss, co-principal investigator and Argonne Distinguished Fellow. Previous battery cells tested in the lab required a separate supply of pure oxygen, requiring a tank of oxygen gas would have to be part of the battery system. A lithium-air battery that uses air from outside eliminates this problem.
“This first demonstration of a true lithium-air battery is an important step toward what we call ‘beyond-lithium-ion’ batteries,” said Amin Salehi-Khojin, assistant professor at the University of Illinois at Chicago
The key to the design is a protective coating for the lithium metal anode, which prevents the anode from reacting with oxygen and deteriorating, coupled with a new electrolyte mixture that allows the cell to operate in an air atmosphere.
Tested in air, the cell maintained high performance during 700 cycles, surpassing previous technologies. “The energy storage capacity was about three times that of a lithium-ion battery, and five times should be easily possible with continued research,” said Salehi-Khojin.
Computational studies at Argonne Leadership Computing Facility (ALCF) and the Centre for Nanoscale Materials (CNM) uncovered how this system operates in air and what factors contribute to the improved cycling stability, while the team at the University of Illinois at Chicago built, tested, analysed and characterized the battery cells.