title: Electronic spin transition in nanosize stoichiometric lithium cobalt oxide.
abstract: A change in the electronic spin state of the surfaces relevant to Li (de)intercalation of nanosized stoichiometric lithium cobalt oxide LiCo(III)O(2) from low-spin to intermediate and high spin is observed for the first time. These surfaces are the ones that are relevant for Li (de)intercalation. From density functional theory calculations with a Hubbard U correction, the surface energies of the layered lithium cobalt oxide can be significantly lowered as a consequence of the spin change. The crystal field splitting of Co d orbitals is modified at the surface due to missing Co-O bonds. The electronic spin transition also has a significant impact on Co(III)-Co(IV) redox potential, as revealed by the change in the lithium (de)intercalation voltage profile in a lithium half cell.
authors.affiliation: Department of NanoEngineering, University of California San Diego, La Jolla, California 92109, USA.
authors.forename: Danna
authors.initials: D
authors.lastname: Qian
authors.forename: Yoyo
authors.initials: Y
authors.lastname: Hinuma
authors.forename: Hailong
authors.initials: H
authors.lastname: Chen
authors.forename: Lin-Shu
authors.initials: LS
authors.lastname: Du
authors.forename: Kyler J
authors.initials: KJ
authors.lastname: Carroll
authors.forename: Gerbrand
authors.initials: G
authors.lastname: Ceder
authors.forename: Clare P
authors.initials: CP
authors.lastname: Grey
authors.forename: Ying S
authors.initials: YS
authors.lastname: Meng