Hierarchical rutile TiO2 with mesocrystalline structure for Li-ion and Na-ion storage

In this paper, we report a one-step and additive-free route for synthesizing hierarchical rutile TiO 2 with mesocrystalline structure. The rutile TiO 2 architecture constructed by oriented tiny nanorod subunits (around 5   nm in diameter) have nano/submicro hierarchical structures, nanoporous nature, a relatively large surface area and high tapped density. When the hierarchical rutile TiO 2 was studied as anode material for Li-ion batteries (LIBs), they exhibited a high reversible capacity of more than 250   mAh   g −1 within a voltage window of 1–3   V, superior rate capability and very good cycling stability with 220   mAh   g −1 after 100 cycles at 0.1   A   g −1 . It’s notable that the hierarchical rutile TiO 2 exhibited superior Li-ion storage properties under deep cycling conditions (0.01-3.0   V), a stable capacity of 346   mAh   g −1 after 100 cycles at 0.1   A   g −1 could be remained. The hierarchical TiO 2 also displayed a large reversible capacity of more than 255   mAh   g −1 (average value) at 0.05   A   g −1 and good cycling performance for Na-ion insertion. These results, in combination with high volumetric storage capacity, render hierarchical rutile TiO 2 a promising anode material for rechargeable batteries.