Optimization of preparation process of coal tar pitch based porous capacitive carbon by response surface methodology
Coal tar pitch is the preferred candidate of preparing carbon electrode materials for supercapacitors.In this paper,porous ca-pacitive carbons were prepared by KOH activation from Angang medium coal tar pitch(AGCTP).Based on the investigation of the effects of carbonization temperature,activation temperature,alkali-carbon ratio,activation time and type of pickling agent on the specific capacitance,a Box-Behnken response surface method was used to optimize the activation preparation conditions of the capaci-tive carbon.The effects of activation temperature,alkali-carbon ratio,activation time and their interactions on capacitance were dis-cussed,and a quadratic regression model between activation process conditions and specific capacitance was obtained.The results show that the porous carbon derived from the raw pitch has the largest capacity,and the washing effect of hydrochloric acid is the best.The activation conditions have significant influence on the specific capacitance,and the optimum activation conditions are as follows:activa-tion temperature of 680 ℃,alkali-carbon ratio of 2.4,and activation time of 2 h.The capacitive carbon produced under this condition shows the specific capacitance of 418 F/g at 0.5 A/g,which is basically consistent with the predicted value of the model,excellent rate capability and small charge transfer impedance(0.17 Ω)and internal resistance(0.72Ω).
Supercapacitorcoal tar pitchcapacitive carbonresponse surface methodologyprocess optimization
万方数据
维普
