Electrospinning Synthesis Of TIN/CNF Composite Nanofibers And Their Application For High Performance Lithium-Ion Batteries

Rechargeable lithium ion batteries (LIBs) have been considered as an ideal power source to meet the growing demand for pervasive electronic uses. New anode materials with higher capacity need to be trenchantly exploited because the commercial carbonaceous anodes with an intrinsic low lithium-ion storage capacity are insufficient to the market needs of high energy density. Sn-based anodes with a high specific capacity of 992mAh·g-1 have attracted tremendous interests. Nevertheless, the Sn-based anodes suffer from poor cycling performance resulting from large specific volume changes and nanoparticle aggregation during repetitious insertion/extraction processes. Therefore, designing new Sn-based anodes with high specific capacities and good cycle performance has become one of the currently significant research hotspots.In this work, Sn nanoparticles-loaded carbon (Sn/C) nanofibers were fabricated from electrospun SnCl4/PAN composite nanofibers by modifying the composition of the spinning solution and the carbonization temperatures. The resultant Sn/C nanofibers with a reticular morphology were directly used as monolithic anodes for LIBs without adding any binder or conducting agent. Changes in the morphology, crystal structure, chemical composition and electrochemical performance of nanofibers were investigated with TEM, FESEM, XRD, FT-IR, EDX and electrochemical characterization respectively. The Sn/C nanofiber anodes carbonized at 700 and 850℃always have much higher reversible capacities than the pure CNFs carbonized at 850℃and the Sn/C anodes carbonized at 1000℃. The Sn/C nanofibers carbonized at 850℃present lower first reversible capacity(993mAh·g-1) but higher coulombic efficiencies(81.7%). The Sn particles with a size of about 30-40 nm embedded in the fiber, but few Sn particles are attached to the nanofiber surfaces when the Sn/C nanofibers was carbonized at 850℃; the Sn/C anode carbonized at 850℃emerged good electrochemical performance with a high reversible capacity of about 440 mAh·g-1 at the 30th cycle.