Controllable Preparation And Electrospinning Of Petroleum-based COPNA Resin

The functional carbon materials derived from aromatic oil have unique advantages due to the high aromaticity,high atmotic ratio of C/H and low content of ash of raw material.Electrospinning is an attracting technique to produce high performance carbon nanofibers due to its wide range of raw materials and good spinnability.Carbon nanofibers with high specific surface area,good electrical conductivity and free standing nature are promising candidate for anode material of lithium-ion secondary batteries(LIBs).It is significant to prepare carbon nanofibers via electrospinning using aromatic oil as carbon source,which can obtain high performance anode material of LIBs and achieve the high value-added utilization of aromatic oil.In the present work,aromatic oil(AO)was employed as the starting material for the synthesis of COPNA resin(condensed polynuclear aromatic resin).COPNA resin was modified by silica nanoparticles and then mixed with polyvinyl-pyrrolidone(PVP)to prepare a suitable feedstock solution for electrospinning.Electrospun fibers(EFs)were heat treated and then immersed into dopamine solution.Carbon fibers(CFs)were finally obtained after successive stabilization and carbonization,and used as electrode material for LIBs.The influential factors on the performance of COPNA resin,and the synthesis and modification mechanism of COPNA resin were investigated respectively.The effect of electrospinning solution concentration on the shape of EFs and the feasibility of avoiding the melting of EFs during the stabilization process via polydopamine coating were also analyzed thoroughly.The influences of carbonization temperature on the performance of CFs and the electrochemical properties of CFs as electrodes for LIBs were investigated.The results show that trioxymethylene(TPF)is better than terephthalyl alcohol(PXG)as a cross-linking agent and nano-silica is better than epoxy resin(EP)as a modifier for the preparation of COPNA resin.The synthetic and modified mechanisms of COPNA resin are cationic electrophilic substitution reaction and dehydration synthesis,respectively.CFs can be obtained when the weight ratio of PVP to Si-R is in the range of(3-5)/15,corresponding to the viscosity range of 273-735 mPa·s.Polydopamine coating with high soften point can form on EFs surface,which can effectively prevent the EFs from melting in stabilization process.The electrical conductivity of CFs is increased from 2.94 to 33.3 S cm-1 with increasing carbonization temperature from 800 to 1000 oC.Obtained CFs exhibited good electrochemical performance as electrode material for LIBs due to the large accessible surface area and high degree of graphitization.The initial discharge specific capacity is nearly 385 m A h g-1 at a current density of 100 m A g-1,and can maintain 216 mA h g-1 after 90 cycles.