title: Structural changes in surface and bulk LiNi0.5Mn0.5O2 during electrochemical reaction on epitaxial thin-film electrodes characterized by in situ X-ray scattering.
abstract: Surface and bulk structural changes of LiNi(0.5)Mn(0.5)O(2) were investigated during electrochemical reaction using synchrotron X-ray scattering and a restricted reaction plane consisting of two-dimensional epitaxial-film electrodes. The changes in bulk structure confirmed lithium diffusion through the (110) surface, which was perpendicular to the two-dimensional (2D) edges of the layered structure. No (de)intercalation reaction was observed through the (003) surface at voltages of 3.0-5.0 V. However, intercalation did proceed through the (003) plane below 3.0 V, indicating unusual three-dimensional (3D) lithium diffusion in the over-lithiated 2D structure. During the electrochemical process, the surface of the electrode showed different structure changes from those of the bulk structure. The reaction mechanism of the intercalation electrodes for lithium batteries is discussed on the basis of surface and bulk structural changes.
authors.affiliation: Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hirayama
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Konishi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sonoyama
authors.forename: Nicolas
authors.initials: N
authors.lastname: Dupré
authors.forename: Dominique
authors.initials: D
authors.lastname: Guyomard
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Tamura
authors.forename: Jun'ichiro
authors.initials: J
authors.lastname: Mizuki
authors.forename: Ryoji
authors.initials: R
authors.lastname: Kanno