title: A Molten Salt Lithium-Oxygen Battery.
abstract: Despite the promise of extremely high theoretical capacity (2Li + O2 ↔ Li2O2, 1675 mAh per gram of oxygen), many challenges currently impede development of Li/O2 battery technology. Finding suitable electrode and electrolyte materials remains the most elusive challenge to date. A radical new approach is to replace volatile, unstable and air-intolerant organic electrolytes common to prior research in the field with alkali metal nitrate molten salt electrolytes and operate the battery above the liquidus temperature (>80 °C). Here we demonstrate an intermediate temperature Li/O2 battery using a lithium anode, a molten nitrate-based electrolyte (e.g., LiNO3-KNO3 eutectic) and a porous carbon O2 cathode with high energy efficiency (∼95%) and improved rate capability because the discharge product, lithium peroxide, is stable and moderately soluble in the molten salt electrolyte. The results, supported by essential state-of-the-art electrochemical and analytical techniques such as in situ pressure and gas analyses, scanning electron microscopy, rotating disk electrode voltammetry, demonstrate that Li2O2 electrochemically forms and decomposes upon cycling with discharge/charge overpotentials as low as 50 mV. We show that the cycle life of such batteries is limited only by carbon reactivity and by the uncontrolled precipitation of Li2O2, which eventually becomes electrically disconnected from the O2 electrode.
authors.affiliation: Liox Power, Inc. , 129 N. Hill Ave., Pasadena, California 91106, United States.
authors.forename: Vincent
authors.initials: V
authors.lastname: Giordani
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Dylan
authors.initials: D
authors.lastname: Tozier
authors.affiliation: Liox Power, Inc. , 129 N. Hill Ave., Pasadena, California 91106, United States.
authors.forename: Hongjin
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States.|Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Colin M
authors.initials: CM
authors.lastname: Burke
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Betar M
authors.initials: BM
authors.lastname: Gallant
authors.affiliation: Liox Power, Inc. , 129 N. Hill Ave., Pasadena, California 91106, United States.
authors.forename: Jasim
authors.initials: J
authors.lastname: Uddin
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Greer
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States.|Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Bryan D
authors.initials: BD
authors.lastname: McCloskey
authors.affiliation: Liox Power, Inc. , 129 N. Hill Ave., Pasadena, California 91106, United States.
authors.forename: Gregory V
authors.initials: GV
authors.lastname: Chase
authors.affiliation: Liox Power, Inc. , 129 N. Hill Ave., Pasadena, California 91106, United States.
authors.forename: Dan
authors.initials: D
authors.lastname: Addison