焦化副产物基多孔碳纳米片的制备及其储电性能

发布时间：2018-05-17 16:11

  本文选题：超级电容器 + 炼焦副产物　； 参考：《安徽工业大学》2017年硕士论文

【摘要】：煤作为我国主要的化石能源之一,在我国的能源结构中占有不可替代的地位。煤碳化炼焦是煤碳利用的主要途径之一,副产大量的煤焦油、煤沥青和蒽油。本文分别以炼焦副产物煤焦油、煤沥青、蒽油为碳源,Mg(OH)_2为模板前驱体,KOH为活化剂,通过高温活化、碳化,制备超级电容器用多孔碳纳米片(Porous carbon nanosheets,PCNSs)。通过透射电镜、扫描电镜和氮吸脱附等手段对所得PCNSs的形貌和孔结构进行表征。采用恒流充放电、循环伏安等技术研究其电化学性能。主要内容如下:(1)以煤焦油为碳源,Mg(OH)_2为模板前驱体,KOH为活化剂时,当三种原料的质量分别为5 g、10 g、20 g,活化终温是800℃时得到的多孔碳纳米片(PCNS_(20-800))的比表面积为3235 m2 g~(-1),平均孔径为2.24 nm。在0.05 A g~(-1)时,PCNS_(20-800)的比容达296 F g~(-1);在20 A g~(-1)时,为220 F g~(-1),其容量保持率为74.32%,显示了高的容量和好的速率性能。在低扫速和高扫速下,其循环伏安曲线均呈现类矩形形状,显示了很好的双电层特性。PCNS_(20-800)的接触内阻仅为0.029Ω,显示了很好的导电性能。在5 A g~(-1),10000次循环之后,PCNS_(20-800)的比容保持率为97.2%,显示了极好的循环稳定性。(2)以煤焦油蒸馏所得残渣煤沥青为碳源,Mg(OH)_2为模板前驱体,KOH为活化剂,三者质量分别为3 g、18 g、18 g,活化终温为800℃时,制得多孔碳纳米片材料(PCNS_(18-800))的比表面积达3145 m2 g~(-1),平均孔径为2.3 nm。在0.05 A g~(-1)的条件下,PCNS_(18-800)的比容为272 F g~(-1),在20 A g~(-1)的条件下,其比容为217 F g~(-1),容量保持率为79.78%,显示了较好的保持率。在5 A g~(-1)电流密度下,恒流充放电循环10000次后,其比容保持率达96.69%,显示了很好的循环稳定性。(3)以煤焦油蒸馏过后所得较轻的组分蒽油为碳源,Mg(OH)_2为模板前驱体,KOH为活化剂,三者质量分别是12 g、12 g、24 g保持不变,改变活化温度,当活化温度900℃时,制备的多孔碳纳米片(PCNS_(900))的比表面积为2087m2 g~(-1),平均孔径为2.7 nm。PCNS_(900)在0.05 A g~(-1)时,其比容为245 F g~(-1),20 A g~(-1)时,其比容为201 F g~(-1),容量保持率为82.04%。PCNS_(900)在5 A g~(-1)时,经过5000次循环后,其保持率为96.52%,显示了很好的循环稳定性。
[Abstract]:As one of the main fossil energy in China, coal plays an irreplaceable role in the energy structure of our country. Coal carbonization is one of the main ways of coal carbon utilization. Coal tar, coal tar and anthracene oil are produced by coal carbonization. In this paper, coking by-product coal tar, coal pitch, anthracene oil as carbon source MgOHHZ2 as template precursor, Koh as activator, through high temperature activation and carbonization, the porous carbon nanosheaths for supercapacitor were prepared. The morphology and pore structure of PCNSs were characterized by transmission electron microscopy, scanning electron microscope and nitrogen adsorption and desorption. The electrochemical performance was studied by constant current charge / discharge and cyclic voltammetry. The main contents are as follows: (1) when coal tar is used as carbon source and MgOHN _ 2 as template precursor and Koh as activator, when the mass of three kinds of raw materials is 5 g / 10 g ~ (20 g), and the final activation temperature is 800 鈩，

本文编号：1902006