Preparation of coal tar pitch-based porous carbon materials and their electric double-layer energy storage performance
As main material for supercapacitor electrodes,porous carbon has the advantages of good electrical conductivity,high chemical stability and wide range of operating temperature.In this paper,porous carbon materials were prepared by chemical activation using In-ner Mongolia coal tar pitch(CTP)as raw material,K2 CO3 and KOH as the activators respectively.The preparation process conditions were optimized,and the differences in structure and electrochemical performance of the porous carbon prepared by the two activators were compared.The results show that the optimal preparation conditions for K2 CO3 and KOH activation are both activation temperature of 700℃ activation time of 60 min,and mass ratio of activator to CTP of 2 ∶ 1.There are significant differences in the microstructure of por-ous carbon prepared by the two activators.The surface of porous carbon(PH-T700)prepared by KOH activation is flat and smooth,with a large number of regular circular pores distributed,but the porous carbon(PC-T700)obtained by K2 CO3 activation shows a coral struc-ture.Compared with PH-T700,PC-T700 has more mesopores and less ionic diffusion resistance.At a current density of 1 A/g,the spe-cific capacitance of PC-T700 and PH-T700 are 252.90 and 261.02 F/g,respectively.PC-T700 and PH-T700 are assembled into button type symmetrical capacitors,with specific capacitance of 226.01 and 225.51 F/g at 0.5 A/g,respectively.PC-T700 shows better rate ca-pability and cycling stability.After 5 000 times of charging and discharging,the specific capacitance of PC-T700 and PH-T700 are 103.77% and 98.20% of the initial values,respectively.When power density reaches 1 038.46 W/kg,the energy density of PC-T700 still maintains 7.5 Wh/kg,which is higher than that of PH-T700.
coal tar pitchporous carbonchemical activationactivatorsupercapacitor
万方数据
维普
