title: New insight into the atomic-scale bulk and surface structure evolution of Li4Ti5O12 anode.
abstract: Identifying the structure of electrodes at atomic-scale remains a key challenge but is a fertile realm for groundbreaking fundamental research in the advanced Li-ion battery material field. In this context, the subtle structure evolution taking place during lithiation/delithiation in the bulk/surface of Li(4)Ti(5)O(12) spinel (LTO) was probed using scanning transmission electron microscopy and found to undergo significant structure torque, namely Ti-O bond stretching/shrinking at different state-of-charge (SOC), which is not identified previously. This kind of nanostructure change plays an important role in facilitating the formation of capturing centers for the electron/hole pairs in a 3.80 eV insulating material as is LTO. Furthermore, with the aid of electron energy loss spectroscopy, the spontaneous charge transfer process, Ti(3+) ↔ e(-) + Ti(4+), was confirmed in the fully lithiated Li(7)Ti(5)O(12) surface as an essential step of the gas-releasing phenomenon. This new insight paves the way toward deeper comprehension and ultimately control of the electrochemical process for this and other important Li-ion battery materials.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Lu
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Hu
authors.forename: Hsien-Chieh
authors.initials: HC
authors.lastname: Chiu
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: George P
authors.initials: GP
authors.lastname: Demopoulos
authors.forename: Liquan
authors.initials: L
authors.lastname: Chen