木质素基纳米炭纤维制备与电容性能研究

Preparation and capacitive properties of lignin-based carbon nanofibers

以碱木质素作为炭前驱体,PVP(聚乙烯吡咯烷酮)作为纺丝助剂,通过静电纺丝技术获得初纺纳米纤维,再经过预氧化、炭化过程制备木质素基纳米炭纤维。通过扫描电镜、XRD、XPS和低温氮吸附等手段对纳米炭纤维的结构进行了表征,并进行三电极电化学测试,通过循环伏安法、恒流充放电和交流阻抗对其电化学性能进行了考察。结果表明:木质素基纳米炭纤维的直径在200~250 nm,比表面积最高达600 m^2/g,纺丝助剂对于纳米炭纤维比表面积的提升和孔结构的调节具有积极的效果,当PVP与木质素的比例为1∶1时,所得纳米炭纤维具有最佳的电容性能,在1 A/g的电流密度下,比电容达到161 F/g。

The lignin-based carbon nanofibers were prepared through pre-oxidation and carbonization by electrospinning using alkali lignin as carbon precursor and PVP（polyvinyl pyrrolidone） as spinning auxiliaries. The structures of the carbon nanofibers were characterized by scanning electron microscopy, XPS, XRD and low temperature nitrogen adsorption. Three electrode electrochemical tests were conducted and the electrochemical performances of the carbon nanofibers were investigated by cyclic voltammetry, constant current charge and discharge and AC impedance. It was found that, the diameter of lignin-based nanofibers was 200-250 nm,and specific surface area was up to 600 m2/g. With the increase of spinning auxiliaries, the pore structure was improved. When the ratio of PVP to lignin is 1∶1, it has excellent specific capacitance of 161 F/g at the current density of 1 A/g.