Preparation Of Fibrous Carbon Composites By Electrospinning And Their Applications In Energy Storage

Electrospinning is an important technology to prepare carbon nanofibers.Carbon fiber is a kind of excellent anode material for lithium-ion batteries?LIBs?due to its small diameter,high conductivity and good mechanical flexibility.With the increasing amount of heavy oil,it is significant to prepare carbon nanofibers via electrospinning from heavy oil,which could obtain high performance anode material for LIBs and find a new way for high value-added utilization of heavy oil.In this work,ZnO/carbon composite fiber,ZnO/asphalt carbon/carbon fiber and multilayer flexible asphalt-base carbon material were prepared via electrospinning.The structures of as-made samples were characterized by Fourier transform infrared spectrometer,X-ray diffractometer,field emission scanning electron microscopy,transmission electron microscopy and so on.The performances of obtained composite as anode for LIBs were investigated.The main contents and results are as following.1.ZnO/carbon fiber was prepared from zinc acetate dihydrate,polyacrylonitrile?PAN?,polyvinylpyrrolidone?PVP?.ZnO on the surface of fiber was coated by 2-3 nm thick carbon layers.The carbon layers could effectively alleviate volume expansion and pulverization of ZnO particles in the charge-discharge processes.ZnO/PP-0.5 with 1:2 of the mass ratio of zinc acetate dihydrate to polymers exhibits a capacity of 703 mAh?g^-1 even after 100 cycles at a current density of 100 mA?g^-1.2.ZnO/asphalt carbon/carbon fiber was prepared by dropping asphalt toluene solution to PAN nanofiber with zinc acetate and subsequent thermal treatment.It is found that asphalt can constitute three dimensional conductive network,whith exhibits high specific capacity and excellent electric conductivity.But too much asphalt will jam the gap between fibers,which is bad for electrolyte dipping and lithium-ion embedding.The sample which the mass ratio of asphalt to fiber is 1:1 exhibit a capacity of 700 mAh?g^-1 after 200 cycles at a current density of200 mA?g^-1.3.Beaded fibers were prepared via blended electrospinning of deoiled asphalt?DOA?toluene solution with PVP ethanol solution.Through alternately electrospinning,flexible multilayer carbon was prepared from PAN and beaded fibers.DOA can enhance the electrical conductivity of as-made sample,and more layers of carbon can enhance the electrochemical performance.The material with five layers exhibits a capacity of 509 mAh?g^-1 even after 100cycles at a current density of 100 mA?g^-1.