Synthesis and Electrochemical Performance of SnOx 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 SnOx quantum dots@Zr-MOFs (UIO-66) composites. The size of as-prepared SnOx nanoparticles is approximately 4 nm. Moreover, SnOx nanoparticles are uniformly anchored on the surface of the Zr-MOFs, which serves as a matrix to alleviate the agglomeration of SnOx grains. This structure provides an accessible surrounding space to accommodate the volume change of SnOx during the charge/discharge process. Cyclic voltammetry and galvanostatic charge/discharge were employed to examine the electrochemical properties of the ultrafine SnOx@Zr-MOF (UIO-66) material. Benefiting from the advantages of the smaller size of SnOx nanoparticles and the synergistic effect between SnOx nanoparticles and the Zr-MOFs, the SnOx@Zr-MOF composite exhibits enhanced electrochemical performance when compared to that of its SnOx bulk counterpart. Specifically, the discharge-specific capacity of the SnOx@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%.