The Preparation And Research Of Nitrogen Enrichment Carbon Materials In Supercapacitor Application

As a new type of energy storage device, the supercapacitors have the features of short charging time,long cycle life, good temperature characteristic, energy conservation and environmental protection, etc.With the deepening theory research of the supercapacitor and rapid development of application technology,to meet different requirements, more and more new and good performance of the super capacitor electrodematerials are needed. At present, the supercapacitor carbon materials are becoming more and more mature,but it has a low specific capacitance. In order to obtain high specific capacitance of carbon materials, weconducted the following researches, the main contents and the results are outlined as follows:Synthesis of poly-N-hydroxyethyl aniline (PNPEA) by chemical oxidation polymerization ofN-hydroxyethyl aniline as monomer, Cetyl trimethyl ammonium bromide (CTAB) as the soft template,ammonium persulfate as the oxidant in the presence of HCl. Nitrogen enrichment carbon materials(C-PNPEA-X, X=600℃,700℃,800℃,900℃) had been synthesized from PNPEA by carbonizationdifferent temperatures in N2protection and characterized physical by SEM, XRD, TEM and IR. In6mol/LKOH solution, the electrochemical performance of the carbon electrode were investigated by cyclicvoltammetry, galvanosatic charge-discharge and ac impedance spectroscope. The results showed that theC-PNPEA-X electrochemical performance were not ideal. By comparison, electrochemical performance ofC-PNPEA-800℃is the best, which the quality specific capacitance reached to220F/g under the currentdensity of0.1A/g and had only55F/g under the current density of5A/g, the quality specific capacitanceis decayed from90F/g to50F/g under the current density of1A/g after1000times cycle charge-discharge,the retention rate is56%.We explored the effects of activation time and activation temperature on the electrochemicalperformance of activated carbon materials (AC) which C-PNPEA-800℃is used as precursor and CO2isused as activating agent. Beside, AC characterized physical by SEM, XRD, TEM and IR. In1mol/L H2SO4solution, the electrochemical performance of the AC electrode were investigated by cyclic voltammetry,galvanosatic charge-discharge and ac impedance spectroscope, and the results showed that the bestactivation conditions is activated by CO2for4h under900℃, and the cyclic voltammogram is rectangular curve; the resistance of solution is2.046, the internal resistance of material is0.806; the quality specificcapacitance is220F/g and155F/g under the current density is0.1A/g and5A/g, respectively; the qualityspecific capacitance has no attenuation under the current density of1A/g after1000times cyclecharge-discharge. So the material shows a good cycle stability.We prepare the PNPEA base carbon materials (PNPEA/KOH-X, X=500℃,600℃,700℃,800℃) byKOH activation under different temperatures, and characterized physical by SEM, XRD and IR. In1mol/LH2SO4solution, the electrochemical performance of the PNPEA/KOH-X electrode were investigated bycyclic voltammetry, galvanosatic charge-discharge and ac impedance spectroscope, the results showed thatelectrochemical performance of PNPEA/KOH-700℃is the best, the cyclic voltammogram curve is regularrectangular, the solution resistance is2.077, the internal resistance of electrode material is1.033; andthe quality specific capacitance are447F/g,412F/g,337F/g,307F/g,280F/g,270F/g under the currentdensity is of1A/g,3A/g,5A/g,10A/g,20A/g,30A/g, respectively; the retention rates of quality specificcapacitor are75%,76%,84%,76%after1000times cycle recharge under the current density is of1A/g,3A/g,5A/g,10A/g, respectively, the conservation rates of quality specific capacitor are83%,95%after10000times cycle recharge under current density of20A/g,30A/g respectively; it shows that the materialhas good cycle reversibility, small internal resistance, high quality of specific capacitance and favorablestability.