Lithium Vanadium Phosphate/Carbon Nanofiber Films as Selfstanding, Binderfree, and Flexible Cathodes for Lithium-Ion Batteries

Flexible lithium vanadium phosphate/carbon nanofiber (i.e., Li3V2(PO4)(3)/C) were fabricated by an electrospinning process combined with hot-pressed sintering, and are used in lithium-ion batteries as selfstanding, binderfree and flexible cathodes. The microstructure and crystalline phase of the as-prepared films are characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry. The electrochemical properties of the Li3V2(PO4)(3)/C nanofiber films were analyzed by cyclic voltammetry and galvanostatic charge/discharge tests. When the nanofiber precursor was sintered at 850 degrees C for 20h, the resulting film displays high flexibility and crystallinity. This selfstanding Li3V2(PO4)(3)/C film exhibits a superior rate performance even at 20C and good cycle ability, with a retention capacity of 112mAhg(-1) at a current density of 1C after 1000 cycles and 71mAhg(-1) at 5C after 800 cycles. These features are attributed to the special composite structure formed by the Li3V2(PO4)(3) and the carbon support, and the 3D long-range conductive networks.