SnO₂/Sn_xMo_1−xO_3−x solid solution nanocomposites: Demonstration of enhanced lithium storage behavior with general synergistic effects

SnO₂/Sn_xMo_1−xO_3−x solid solution-based nanocomposites have been prepared via a two-step hydrothermal and following annealing processes. At a Sn/Mo molar ratio of 1:2 (the Sn/Mo = 1:2), a single-phase Sn_xMo_1−xO_3−x with ionic flake-like structure can be obtained; while, a SnO₂/Sn_xMo_1−xO_3−x solid solution nanocomposite can be obtained at a Sn/Mo molar ratio of 1:1 (the Sn/Mo = 1:1), which combines with iconic sphere and flake-like structure. Then, electrochemical properties are systematically studied with pure SnO₂ and pure MoO₃ comparisons as anodes for LIBs. The after cycled Sn/Mo = 1:1 electrode could contain three phases of metallic Sn, MoO₂ and an amorphous Sn-Mo oxides, which provide a general synergistic effect to enhance the surface charge contribution, reduce the charge transfer resistance and increase the reaction kinetics. Specifically, the Sn/Mo = 1:1 electrode exhibits a high initial coulombic efficiency of 73.5% with an excellent reversible lithium storage capacity of 735 mAh g⁻¹ at a current density of 0.4 A g⁻¹ after 500 cycles, and a high-rate performance with a specific capacity of 337 mAh g⁻¹ can be obtained at current density of 4 A g⁻¹. This work could provide some inspirations to design solid solution-based nanocomposite with a general synergistic effect to enhance the electrochemical performance for lithium storage application.