Porous SnO2–Fe2O3 nanocubes with improved electrochemical performance for lithium ion batteries

Abstract

Mixed oxide SnO₂–Fe₂O₃ porous nanocubes were prepared by simply annealing the precursor of Sn₃[Fe(CN)₆]₄ nanocubes, which were obtained through a facile solvothermal method. Calcination of the precursor at 350 °C produced uniform SnO₂–Fe₂O₃ nanocubes without obvious morphological deformation, but with lots of open void space in the nanocubes. The Brunauer–Emmett–Teller N₂ adsorption–desorption analysis shows that the as-synthesized SnO₂–Fe₂O₃ has a specific surface area of 170.2 m² g⁻¹ with a pore size of around 5 nm. The porous SnO₂–Fe₂O₃ nanocubes as anode materials for the lithium-ion battery show a high initial capacity of 1020.2 mA h g⁻¹ at a current density of 200 mA g⁻¹ and maintain at 567.5 mA h g⁻¹ at the 50th cycle, which is distinctly higher than those reported for SnO₂-based materials. The enhanced performance towards lithium storage can be ascribed to the high specific area, an appropriate pore size and the synergistic effect of SnO₂ and Fe₂O₃.