Preparation Of Novel N-doped Carbon Materils And Their Electrochamical Performance

Walnut shell and graphite powder were used to prepare Active Carbon and GraphiteOxide, and then different methods were taken to prepare N-doped active carbon, N-dopedgraphene and N-doped active carbon/graphene composites with high specific area andhigh specific capacitance by utilizing different N sources. The micro structurecharacteristics, micro surface morphologies, porous structures and oxygen-containingfunctional groups were analyzed by XRD、FT-IR、Raman and N2adsorption-desorptionisotherms methods. The electrochemical performance and the impact of the introduction ofN atoms to the structure of the N-doped active carbon、N-doped graphene and N-dopedactive carbon/graphene composites were studied as well.The specific capacitance of the active carbon using urea as N source is improved a lotafter heating treatment and the resistance is discovered quite low.The specific capacitancereach the max value156.3F/g under the current density of1A/g when the ratio of activecarbon and urea is1:5.The stability is96.2%after1000cycles test.Different N sources and methods is applied to prepared NG with various characters.The CV results show that the NG using ammonia as N source after hydrothermal exhibitsdouble-layer capacitor property after oxygen-containing groups removed efficiently.According CD results we can know that the NG using ammonia as N source afterhydrothermal obtain the capacitance of174F/g at the current density of1A/g. The stabilityis91.7%after1000cycles test.N-doped active carbon/graphene composites prepared with the N-doped activecarbon and N-doped graphene show a quite low resistance and high specific capacitance.The resistance is as low as0.437Ωwhen the ratio of NG and NAC is1:6and the specificcapacitance can be203.7F/g at the current density of1A/g, which is much higher than NGand NAC respectively. The stability is93.4%after1000cycles test.