Study On Electrospinning Co / C Nanofibers And Their Properties

As a new environmentally and friendly green energy battery, Lithium-ion battery has attracted much attention in the field of mew energy duo to its environmental protection, high specific capacity, long life and high safety, and it has great application potential on the electric vehicle and other large power equipment. The anode material is one of the key factors affecting the performance of lithium-ion batteries. In spite of the commercialization of the carbon material as anode material, the capacity is still relatively low, which limits its application in the field of energy storage.Therefore, it is a pressing problems that the new high-performance anode materials are explored to instead of graphite and it is one of the main factors on improving the performance of Lithium-ion battery. In order to meet the requirements, researchers from all over the world are committed to finding new high-performance anode material. In recent years, the transition metal Co is becoming a research candidate as anode materials of lithium-ion battery due to its rich source, low-cost, environmentally and friendly, high specific capacity and so on. However, the transition metal Co as an anode material of lithium-ion battery is observed the large volume changes during the Li+ insertion-extraction process, that result capacity fade and poor cycle performance. In the paper to improve their electrochemical performance,we have been devoted on two aspects as follows:fabrication of nano-sized the transition metal Co and combining the transition metal Co with carbon nanofibers.In this work, electrospinning Co/C nanocomposite fibers were obtained by using electrospinning apparatus prepared with polyacrylonitrile (PAN), N,N-dimethylformamide (DMF) and Cobalt acetate (Co(CH3COO)2.4H2O) and subsequent heat treatment.They were characterized and analyzed by scanning electron microscopy(SEM),transmission electron microscopy(TEM),High resolution transmission electron microscopy(HRTEM), X-ray diffraction(XRD), thermogravimetric analysis(TG) and charge-discharge measurements. The results exhibit that along with Co content increasing, the fibers has good morphology while the diameters become larger and cobalt elemental particles on the fibers become more dense. We found when Co content is 33.6 wt.% as anode bettery material, electrospinning Co/C nanocomposite fibers have the best electrochemical performance and rate performance.And after one hundred fifty cycles the discharge capacity of electrospinning Co/C nanocomposite fibers was maintained at 507.9 mAh/g.