Unique Structural Changes of Three-Dimensionally Ordered Macroporous TiO2 Electrode Materials During Electrochemical Cycling

Abstract

Structural changes during lithium intercalation (to x = 1.1 in LixTiO2) are studied in three-dimensionally ordered macroporous (3DOM)-TiO2 (figure) prepared by colloidal crystal templating. During the charging/discharging cycles, the pristine crystalline domains are pulverized to smaller nanodomains (∼4 nm), but the original 3DOM structure remains robust and maintains its pristine pore-wall thickness. The long-range ordered crystalline orthorhombic phase is partially transformed into the short-range order amorphous phase and Jahn-Teller distortion is also observed.