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

SnO 2 /TiO 2 nanocomposites are fabricated by depositing amorphous SnO 2 and TiO 2 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 SnO 2 /TiO 2 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 TiO 2 layers can limit the volume expansion of SnO 2 layer, and the densely packed film structure can avoid aggregation of the nanoparticles and assure structural integrity. Our SnO 2 /TiO 2 nanocomposite, taking advantage of the high specific capacity of SnO 2 and the long cycle life of TiO 2 , has potential applications in high performance LIBs, especially in thin-film microbatteries and flexible lithium batteries.