Synthesis and Electrochemical Performance of SnO_x Quantum Dots@ UiO-66 Hybrid for Lithium Ion Battery Applications

A novel method that combines the dehydration of inorganic clusters in metal–organic frameworks (MOFs) with nonaqueous sol–gel chemistry and pyrolysis processes is developed to synthesize SnO x quantum dots@Zr-MOFs (UIO-66) composites. The size of as-prepared SnO x nanoparticles is approximately 4 nm. Moreover, SnO x nanoparticles are uniformly anchored on the surface of the Zr-MOFs, which serves as a matrix to alleviate the agglomeration of SnO x grains. This structure provides an accessible surrounding space to accommodate the volume change of SnO x during the charge/discharge process. Cyclic voltammetry and galvanostatic charge/discharge were employed to examine the electrochemical properties of the ultrafine SnO x @Zr-MOF (UIO-66) material. Benefiting from the advantages of the smaller size of SnO x nanoparticles and the synergistic effect between SnO x nanoparticles and the Zr-MOFs, the SnO x @Zr-MOF composite exhibits enhanced electrochemical performance when compared to that of its SnO x bulk counterpart. Specifically, the discharge-specific capacity of the SnO x @Zr-MOF electrode can still remain at 994 mA h g –1 at 50 mA g –1 after 100 cycles. The columbic efficiencies can reach 99%.