Facile fabrication of SnO2@TiO2 core-shell structures as anode materials for lithium-ion batteries

A novel strategy to fabricate SnO2@TiO2 composite was developed by combining the glucose-mediated hydrothermal method along with a sol-gel step, followed by a sintering process. Herein, glucose was found to play dual roles of facilitating the rapid precipitation of polycrystalline SnO2 nanocolloids in the hydrothermal process and act as a pore-forming material to leave behind nanopores when it is combusted in the sintering process. Due to the combined superiority of TiO2 as a inert nanoshell and SnO2 as a core with a high theoretical specific capacity, together with the combustion-formed carbon-derived voids with many extra free spaces to buffer the volume change, the obtained SnO2@TiO2 composite has potential for use as an anode material for lithium-ion batteries with enhanced electrochemical performances. A high reversible capacity of 910 mA h g(-1) was maintained over 300 cycles at a current density of 100 mA g(-1). Even at a high current density of 1000 mA g(-1), the substantial discharge capacity could still reach 617 mA h g(-1) after 1000 repeated cycles. Such excellent cycling stability and remarkable rate capability of the designed SnO2@TiO2 composite can be attributed to its novel structure and the synergistic effects between the SnO2 core and TiO2 shell.