Preparation of nanoporous Sn-doped TiO2 anode material for lithium-ion batteries by a simple dealloying method

Nanoporous Sn-doped TiO2 (NP-TiO2/Sn) composite is successfully fabricated by etching AlTiSn ternary alloy ribbons in NaOH solution at room temperature. The NP-TiO2/Sn composite exhibits a 3D nanosponge structure accompanied with nanowires on it. Besides, Sn nanoparticles embed into the ligaments of amorphous TiO2. Owing to the unique hierarchical structure and the introduction of Sn, the NP-TiO2/Sn composite exhibits enhanced rate capacities and long cycling life compared with non-added Sn composition. Moreover, it also performs good cycling life and coulombic efficiency at both low and high current densities. When atomic ratio of Ti and Sn is 9:1, the best discharge capacity and cycling performance are exhibited. After circulating 300 cycles at 1 A g(-1), the NP-TiO2/Sn composite shows a high capacity, which doubles pure NP-TiO2. The good electrochemical performance and facile process favor the practical utilization as the anode material of lithium-ion batteries.