Synthesis&Capacitance Property Of N-doped Porous Carbon/Nickel(Ferric)Manganese Oxides Accompanied With Carbon Tubes

Due to the wide use of electromobiles requiring high power output in recent years,the energy-storage devices such as supercapacitors have become more and more important.All countries in the world are very concerned about the researches on electrode materials of supercapacitors because the supercapacitor performance depends on the electrode materials.In this paper,Huating coal was deashed and used as raw material,and then aniline adsorbed in the pores or on the surface of coal was polymerized in situ to obtain coal-based polyaniline?CPANI?.Using nickel acetate?or iron citrate?as the catalyst precursor,N-doped porous carbon was prepared through the high-temperature catalytic pyrolysis of CPANI.In the same time,using the gaseous organic molecules produced by the process of high-temperature catalytic pyrolysis as carbon sources and dicyclopentadienyl nickel?or ferrocene?as the catalyst precursor,carbon tubes were synthesized by the chemical vapor deposition method.The as-prepared N-doped porous carbon/nickel?iron?was oxidized by potassium permanganate to N-doped porous carbon/nickel?iron?manganese oxides.Then carbon nanotubes were added to obtain N-porous carbon/nickel?iron?manganese oxides/carbon nanotubes.Their structures were characterized by SEM,TEM,XRD,XPS,FTIR,and nitrogen adsorption analysis,and the electrochemical performance tests of electrode materials on the electrochemical station.Main research results are listed as follows:?1?Using nickel acetate or ferric citrate as the catalyst precursor,N-doped porous carbon was successfully prepared by high-temperature catalytic pyrolysis of CPANI.And most of the N-doped porous carbon exists in the amorphous structure,a few exists in the graphitization structure.N element was successfully doped into the porous carbon,and the as-doped N presents in pyridinic N,pyrrolic N or graphitic N.N-doped porous carbon/nickel-N5 possesses rich mesopores,its BET specific surface area is 801.59 m²/g,BJH average pore size is 4.40 nm,and the yield of porous carbon is 32.16%.N-doped porous carbon/nickel-T1 also possesses rich mesopores,its BET specific surface area is 1087.42 m/g,BJH average pore size is 3.16 nm,and the yield of porous carbon is 19.69%.?2?In N-doped porous carbon/nickel manganese oxide-NM2,nickel manganese oxide mainly exists in the chemical state of NiO,associated with nanometer-sheet NiMn₂O₄ and?-MnO₂ attached on the surface of porous carbon or inserted in the pore.The specific capacitance of as-prepared N-doped porous carbon/nickel manganese oxide-NM2 is 384.7 F/g?1 A/g?.The specific capacitance of N-doped porous carbon/nickel manganese oxide/carbon nanotubes-NMC1 is 478.6 F/g?1 A/g?and remains 81.16%after 500-cycle charge and discharge at the high current density of 5 A/g.Its conductivity is higher nearly two times than that of NM2.In N-doped porous carbon/iron manganese oxide-TM3,iron mainly exists in nanometer-sheet Fe2O3 and Fe₃O₄,and manganese exists in nanometer-sheet Mn₂O₃ and Mn₃O₄ attached on the surface of porous carbon or inserted in the pore.The specific capacitance of as-preparated N-doped porous carbon/iron manganese oxide-TM3 is 414.8 F/g?1 A/g?.The specific capacitance of N-doped porous carbon/iron manganese oxide/carbon nanotubes-TMC2 is 503.4 F/g?1 A/g?and remains 88.04%after 500-cycle charge and discharge at the high current density of 5 A/g.Its conductivity is higher nearly four times than that of TM3.?3?The diameter of carbon tubes prepared with nickelocene as the catalyst is 150?400 nm,and most carbon tubes are about 60 nm diametral and 10 nm thick.The total yield of carbon tubes is 2.01 g/1.00 g?nickelocene?and/16.00 g?CPANI?.The diameter of carbon nanotubes prepared with ferrocene as the catalyst is 23?128 nm,and most carbon tubes is 35 nm?75 nm diametral and 5 nm?40 nm thick.The total yield of carbon nanotubes is 2.82 g/1.00 g?ferrocene?and/5.00 g?CPANI?and becomes 1.06 g//1.00 g?ferrocene?and/5.00 g?CPANI?after the purification.