Preparation of core-shell Sn /C encapsulated carbon nanofibers and its application as anode materials for lithium-ion battery

Core /shell nanofibers were successfully prepared by co-axial electrospinning,using carbon as the core and Sn /C as the shell.According to the classical electrospinning theory to calculate the diameter of nanofibers,core /shell namofibers with different diameter ratios were prepared by adjusting the speed ratio of electrospinning and the resulting product was applied to the anode material of lithium-ion battery.The morphology of core /shell nanofibers was characterized by transmission electron microscopy.X-ray diffractometer was used to assess the structure of the nanofibers.Especially,the electrochemical properties were detected.The study revealed that core /shell nanofibers with different diameter ratios were obtained by adjusting core /shell electrospinning speed ratio;the crystal structure containing tin and amorphous carbon were formed after carbonized at 800 ℃;and when the core /shell electrospinning speed ratio at 1 ∶ 1,carbon /tin encapsulated carbon nanofibers owned the best cycle stability,the capacity retention is 69% after 50 cycles.