title: Spinel-type lithium cobalt oxide as a bifunctional electrocatalyst for the oxygen evolution and oxygen reduction reactions.
abstract: Development of efficient, affordable electrocatalysts for the oxygen evolution reaction and the oxygen reduction reaction is critical for rechargeable metal-air batteries. Here we present lithium cobalt oxide, synthesized at 400 °C (designated as LT-LiCoO2) that adopts a lithiated spinel structure, as an inexpensive, efficient electrocatalyst for the oxygen evolution reaction. The catalytic activity of LT-LiCoO2 is higher than that of both spinel cobalt oxide and layered lithium cobalt oxide synthesized at 800 °C (designated as HT-LiCoO2) for the oxygen evolution reaction. Although LT-LiCoO2 exhibits poor activity for the oxygen reduction reaction, the chemically delithiated LT-Li1-xCoO2 samples exhibit a combination of high oxygen reduction reaction and oxygen evolution reaction activities, making the spinel-type LT-Li0,5CoO2 a potential bifunctional electrocatalyst for rechargeable metal-air batteries. The high activities of these delithiated compositions are attributed to the Co4O4 cubane subunits and a pinning of the Co(3+/4+):3d energy with the top of the O(2-):2p band.
authors.affiliation: Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Thandavarayan
authors.initials: T
authors.lastname: Maiyalagan
authors.affiliation: Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Karalee A
authors.initials: KA
authors.lastname: Jarvis
authors.affiliation: Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Soosairaj
authors.initials: S
authors.lastname: Therese
authors.affiliation: Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Ferreira
authors.affiliation: Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Manthiram