ZnS@C/rGO复合材料的制备及其电化学可逆储锂性能

通过溶剂热反应-水热处理的途径，制备了无定形碳包覆的ZnS纳米晶体（ZnS@C）与还原氧化石墨烯（rGO）复合的ZnS@C/rGO复合材料，并用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和X射线光电子能谱（XPS）对复合材料进行了形貌和微观结构的表征。电化学测试结果表明，与ZnS@C和ZnS/rGO相比，所制备的ZnS@C/rGO复合材料显示了显著增强的电化学储锂性能，在100 mA·g^-1电流密度下，其电化学储锂的首次可逆比容量为1 101 mAh·g^-1，充放电循环100次后其可逆比容量为1 569 mAh·g^-1。在不同电流密度下循环1 200次后，仍保持在2.0 A·g^-1电流密度下有1 096 mAh·g^-1的可逆比容量，显示了其稳定的长循环性能。

Preparation of ZnS@C/rGO Composite for Electrochemical Reversible Lithium Storage

ZnS@C/reduce graphene oxide (rGO) composite was prepared by solvothermal reaction-hydrothermal treatment route. ZnS nanocrystal coated by amorphous carbon (ZnS@C) was prepared by the first-step solvothermal reaction, then ZnS@C/rGO was prepared by the second-step hydrothermal treatment. The morphology and microstructure of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical test results demonstrated that the as-prepared ZnS@C/rGO composite exhibited significantly enhanced electrochemical lithium storage performance in comparison to ZnS@C and ZnS/rGO. At the current density of 100 mA·g^-1, ZnS@C/rGO electrode delivered the reversible specific capacity of 1 101 mAh·g^-1 and 1 569 mAh·g^-1, respectively, at the 1st and 100th cycle. After 1 200 cycles at the different current densities, the reversible specific capacity of 1 096 mAh·g^-1 was remained at 2.0 A·g^-1, indicating its stable long-cycle performance.