In situ synthesis of mesoporous single-grain layer anatase TiO2 nanosheets without additives via a mild and simple process for a long-term Li-ion battery

Abstract

There are few reports on mesoporous anatase TiO₂ nanosheets being synthesized without additives and ex situ templates under mild conditions. In this study, mesoporous single-grain layer anatase (MSGLA) TiO₂ nanosheets were first synthesized in situ without additives in a new methanol–tetrabutyl titanate (TBT) system on a large scale using a simple and easily reproducible method. The formation mechanism of the MSGLA TiO₂ nanosheets was investigated in detail. The results suggest that MSGLA TiO₂ nanosheets can be obtained after a simple thermal treatment of amorphous TiO₂ sheets that are converted in situ from the precursor Ti(OC₄H₉)_4−n(OCH₃)_n (1 ≤ n ≤ 4) (TBM), which is gained easily via the transesterification reactions of TBT and anhydrous methanol at room temperature. Moreover, the MSGLA TiO₂ nanosheets were applied successfully as anode materials for Li-ion batteries (LIB) and exhibited a discharge capacity of ∼73 mA h g⁻¹ with obvious voltage plateaus over 4000 cycles (a test time of ∼50 days) at 5 C (1 C = 170 mA g⁻¹) and Coulombic efficiencies of each cycle approaching 100%, highlighting them as promising materials for long-term LIB.