Study of the insertion mechanism of lithium into anatase by operando X-ray diffraction and absorption spectroscopy

Operando X-ray diffraction (XRD) and X-ray absorption (XAS) were used to study Li+ insertion into TiO2 anatase during electrochemical cycling in a Li cell. The evolution of long range order and local structure with the amount of lithium reacted were analyzed to identify and characterize the individual insertion domains. These results agree with a three-step insertion process, firstly solid solution, followed by characteristic bipliasic plateau corresponding to the transformation from tetragonal to orthorhombic phase which is succeeded by a monophasic insertion. (C) 2014 Elsevier B.V. All rights reserved.