‘Isofacet’ anatase TiO2 microcages : topotactic synthesis and ultrastable Li-ion storage

Abstract

A new type of anatase TiO2 microcages assembled by oriented nanocrystals have been successfully fabricated through a topotactical conversion from CaTiO3 microcage precursor. The anatase microcages have all their six side faces dominated by anatase {001} facets, as revealed by detailed electron microscopy characterization. When used as the anode material for Li-ion storage, the unique microcages have the advantage of remarkable structural stability, high surface areas, and facile electronic conduction path. As a result, the TiO2 microcages-based anode achieves a high lithium storage performance especially at high current rates and long cycling stability, giving 175 mAh g-1 at 5C (850 mA g-1) after 800 cycles and 95 mAh g-1 at 50 C after 5000 cycles. Our comparison to the literature shows that this is a competitive and promising material for Li-ion battery and potentially also photocatalyst applications.