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Preparation And Electrochemical Performance Of Phenol Formaldehyde Resin-based Porous Carbon Materials For Supercapacitor

Posted on:2017-04-09Degree:MasterType:Thesis
Country:ChinaCandidate:X Q ChangFull Text:PDF
GTID:2311330491960646Subject:Polymer Chemistry and Physics
Abstract/Summary:PDF Full Text Request
Phenolic resin?RF?has been widely focused and studied due to its excellent properties of simple process,abundant raw materials,low cost,stable product structure,flame retardant,hest resistance and so on.In recent years,the carbonized RF has been applied to the super capacitors?SC?field,which promotes futher development of SC.The distribution of specific surface area and pore size of the carbon materials vary with its preparation methods,generally speaking,of which the more number of microporous and mesoporous,specific surface area are,the more conducive to improve its electrical properties.In addition,conducting polymers such as polyaniline?PANI?with excellent electrical conductivity and easily synthesized,but poor cycle stability can contribute to synergism and complementary adcantages of the two,and effective improvement of the material specific capacitance.From the perspective of safety,enviromental protection,energy saving and high efficiency,since polymer based carbon materials is low-cost,easily synthesized and modified,it possesses a potential advantage to serve as high performance electrode materials of SC.The main research contents of this paper are as follows:1.Yolk-shell structure of phenolic resin?YRF?is prepared by the condensation of resorcinol and formaldehyde polymerization with the catalysts as ammonia adopting the template free method in ethnol-water system.It mainly investigates the effects of amount of ethanol and ammonia,synthesis temperature and synthesis time on the yolk-shell morphology,and characterizes the YRF structure with SEM,TEM,XRD and FTIR.It can still maintain the yolk-shell morphology after carbonization at high temperature,indicating an excellent stability.The experiment uses electrochemical test methods,such as CV,GCD as well as EIS to characterize the electrochemical of YRFC700,the results exhibit typical electric double layer capacitor?EDLCs?behavior.At the current density of 1A g-1,the specific capacitance of YRFC700 is up to 121.7 F g-1,which contains a potential advantage to serve as SC electrode materials.2.The yolk-shell structure of phenolic resin is activated by nitric acid?HNO3?activation and KOH activation method.In the process of HNO3 activated,we explore the performance influence of the different activation time,activation temperature and concentration of HNO3 solution for YRF.The electrochemical tests show that the the specific capacitance of activated material?NYRFC?is higest when the temperature at 80 oC,activated time in 5h,the concentration of HNO3 at 6mol L-1.The specific capacitance of NYRFC is up to 262.2 F g-1 at a current density of 0.5 A g-1.When the materials are activated by KOH,we explore the affect to the capacitance for YRF of different activated mass ratio,activated temperature.According to the electrochemical testing,the specific capacitance of YRFC700-1:3 is up to 397.4 F g-1 at a current density of 0.5A g-1 and retains 91.2% after 10000 charge-discharge processes at a current density of 20 A g-1.The energy density is up to 24.83 Wh kg-1 when the power density at 28.84 k W kg-1.The unique yolk-shell structure is more conducive to the embedding and extraction of electrolyte ion,which shorts the transportation distance of ions and improves the specific capacitance of the material.3.The solid structure of phenolic resin is prepared by the condensation of resorcinol and formaldehyde polymerization with the ammonia as catalysts under the temperature of 10 oC.Dispersing the solid structure of RFC in 3 mol L-1 H2SO4 solution,different doses of aniline?AN?is in-situ polymerization by induced in ammonium sulfate?APS?,using TEM,SEM,FTIR and XRD analyze the morphology structure of obtained composite material,the results show that pure linear PANI overlapped like the chrysanthemum structure.According to the galvanostatic,the results show that the specific capacitance?CSP?of PRFC-2:1 is up to 315 F g-1 at a current density of 1 A g-1.PRFC-2:1 is much higher than that of pure PAN and RFC under high current density.The specific capacitance retains 80.0% after 1000 chargedischarge process at the current density of 5 A g-1.It can be seen from the TEM that at the quality ratio of 2:1,there are a lot of floc on the surface and the capacitance has been improved due to the synergistic effect of polyaniline and carbon materials.
Keywords/Search Tags:Phenolic resin, Carbon materials, Yolk-shell structure, Supercapacitor, Polyaniline
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