title: Combining Accurate O2 and Li2O2 Assays to Separate Discharge and Charge Stability Limitations in Nonaqueous Li-O2 Batteries.
abstract: Li-air batteries have generated enormous interest as potential high specific energy alternatives to existing energy storage devices. However, Li-air batteries suffer from poor rechargeability caused by the instability of organic electrolytes and carbon cathodes. To understand and address this poor rechargeability, it is essential to elucidate the efficiency in which O2 is converted to Li2O2 (the desired discharge product) during discharge and the efficiency in which Li2O2 is oxidized back to O2 during charge. In this Letter, we combine many quantitative techniques, including a newly developed peroxide titration, to assign and quantify decomposition pathways occurring in cells employing a variety of solvents and cathodes. We find that Li2O2-induced electrolyte solvent and salt instabilities account for nearly all efficiency losses upon discharge, whereas both cathode and electrolyte instabilities are observed upon charge at high potentials.
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.
authors.forename: Bryan D
authors.initials: BD
authors.lastname: McCloskey
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.|University of Grenoble, Phelma Grenoble INP, Minatec , CS 50257, 38016 Grenoble, Cedex 1, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Valery
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.|SUNCAT, SLAC National Accelerator Laboratory , Menlo Park, California 94025-7015, United States.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Luntz
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.
authors.forename: Sanketh R
authors.initials: SR
authors.lastname: Gowda
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Wallraff
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Garcia
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.|Central Glass International Inc. , 2033 Gateway Place, Suite 569, San Jose, California 95110, United States.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mori
authors.affiliation: IBM Almaden Research Center , San Jose, California 95120, United States.
authors.forename: Leslie E
authors.initials: LE
authors.lastname: Krupp
keywords: Li−air battery; cathode; decomposition; electrolyte; peroxide; titration