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 TiO2 with mesocrystalline structure. The rutile TiO2 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 TiO2 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 TiO2 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 TiO2 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 TiO2 a promising anode material for rechargeable batteries.