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

Structural changes during lithium intercalation (to x = 1.1 in Li_xTiO₂) 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.