Electrospinning synthesis of Li-Fe-P/PAN based micro-nanofibers as precursors for LiFePO4 cathode materia! in Li-ion fiber battery applications

摘要

The increase popularity of wearable devices and smart textiles are being held back partly by better energy storage systems,which are based on electrochemical phenomena.Research in novel materials with optimal morphologies for better electrochemical performance is one the paths being followed.Micro/nano fibers are interesting morphologies as they present high surface areas,less agglomeration and flexibility,compared to micro/nano particles.In this article,precursor fibers for LiFePP4 cathode material,defined as lithium-iron-phosphorous/polyacrylonitrile {Li-Fe-P/PAN)precursor nanofibers,have been synthesized by the electrospinning method.The influence of electrospinning parameters such as voltage(V),flow rate(F)and distance between the collector and the tip of the syringe needle(D),on the morphology of the fibers have been studied mainly by scanning electron microscopy(SEM).Optimal morphological features such as less formation of beads,small fiber diameter,less polydispersity and high fiber alignment,were observed at V=14 kV,F=0.7 mL/h and D=14 cm.The occurrence of nanofibers on the precursor Li-Fe-P/PAN material was observed through SEM,while the energy dispersive x-ray spectroscopy(EDS)confirms the presence of the fundamental elements in the precursor nanofibers.