Self-Supported Amorphous SnO2/TiO2 Nanocomposite Films with Improved Electrochemical Performance for Lithium-Ion Batteries

SnO2/TiO2 nanocomposites are fabricated by depositing amorphous SnO2 and TiO2 films alternately using pulsed laser deposition (PLD) system. The prepared nanocomposite anode delivers a high reversible capacity of 175 μA h cm−2 at 13.8 μA cm−2 after 200 cycles, and exhibits high rate capability (111 μA h cm−2 at 276 μA cm−2). Additionally, a quasi-solid-state battery is also assembled by using the granular film as a self-supporting electrode material, which displays superior cycling stability (136 μA h cm−2 at 13.8 μA cm−2 after 200 cycles). The excellent performance of the SnO2/TiO2 multilayer anodes can be attributed to the multilayer heterogeneous structure and component. In such a granular film structure, the amorphous structure can not only buffer stress, but also promote the diffusion of Li ions. Furthermore, the TiO2 layers can limit the volume expansion of SnO2 layer, and the densely packed film structure can avoid aggregation of the nanoparticles and assure structural integrity. Our SnO2/TiO2 nanocomposite, taking advantage of the high specific capacity of SnO2 and the long cycle life of TiO2, has potential applications in high performance LIBs, especially in thin-film microbatteries and flexible lithium batteries.