Controllable Synthesis of NaV(PO)/C Nanofibers As Cathode Material for Sodium-Ion Batteries by Electrostatic Spinning

NaV(PO)/C nanofibers are prepared by a pre-reduction assisted electrospinning method. In order to maintain the perfect fibrous architecture of the NaV(PO)/C samples after calcining, a series of heat treatment parameters are studied in detail. It is found that the heat treatment process shows important influence on the morphology and electrochemical performance of NaV(PO)/C composite nanofibers. Under the calcining conditions of 800°C for 10 h with a heating rate of 2.5°C min, the well-crystallized uniform NaV(PO)/C nanofibers with excellent electrochemical performances are successfully obtained. The initial discharge specific capacities of the nanofibers at 0.05, 1, and 10C are 114.0, 106.0, and 77.9 mAh g, respectively. The capacity retention still remains 97.0% after 100 cycles at 0.05C. This smooth, uniform, and continuous NaV(PO)/C composite nanofibers prepared by simple electrospinning method, is expected to be a superior cathode material for sodium-ion batteries.