Electrospun Hollow NIO/C Nanocomposite Fiber And Its Lithium Electrical Properties

In this paper,electrospinning technique is introduced to prepare Ni(CH3CO2)2-PAN nanocomposite fibers using nickel acetate[Ni(CH3CO2)2·4H20]and polyacrylonitrile(PAN)as the precursors.And then,after pre-oxidation and carbonization,the precursor of Ni/C was prepared.The nanofibers incorporated with NiO hollow nanoballs were fabricated after oxidated about 2 h in air at 300℃.The samples with different oxidation stages were prepared after oxidated for different time.Data of XRD and TEM shows that the formation of the nanofibers incorporated with NiO hollow nanoballs is driven by Kirkendall effect.The internal structure of the sample undergoes the evolution process of solid,nuclear shell,hollow,and Ni changes to NiO by oxidated in the air at 300℃ step by step.Electrochemical performances of NiO/CNFs with different oxidated time were tested,and the best comprehensive performance of NiO/CNFs-2 was found.NiO/CNFs-2 gives a high discharge value of 1629.1 mA h·g-1 at the first cycle which decreases to 1087 mAh-g-1 at the second run.The Kulun efficiency at the first cycle is 66.72%.NiO/CNFs-2 exhibits high retention efficiency with a stable specific capacity of 497.3 mAh g’1 after 100 cycles at a current density of 50 mA g-1.Thus,we prove that the proper holding time can improve the capacity and the electrochemical performance of the composite fiber.