title: Extracting the redox orbitals in Li battery materials with high-resolution x-ray compton scattering spectroscopy.
abstract: We present an incisive spectroscopic technique for directly probing redox orbitals based on bulk electron momentum density measurements via high-resolution x-ray Compton scattering. Application of our method to spinel Li_{x}Mn_{2}O_{4}, a lithium ion battery cathode material, is discussed. The orbital involved in the lithium insertion and extraction process is shown to mainly be the oxygen 2p orbital. Moreover, the manganese 3d states are shown to experience spatial delocalization involving 0.16±0.05 electrons per Mn site during the battery operation. Our analysis provides a clear understanding of the fundamental redox process involved in the working of a lithium ion battery.
authors.affiliation: Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: B
authors.initials: B
authors.lastname: Barbiellini
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Orikasa
authors.affiliation: Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Go
authors.affiliation: Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.|Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, aleja Mickiewicza 30, 30-059 Krakow, Poland.
authors.forename: S
authors.initials: S
authors.lastname: Kaprzyk
authors.affiliation: Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Itou
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Uchimoto
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.|Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Yung Jui
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: H
authors.initials: H
authors.lastname: Hafiz
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bansil
authors.affiliation: Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai