【作者】 卢海；

【导师】 赖延清； 张治安；

【作者基本信息】 中南大学 ， 冶金物理化学， 2007， 硕士

【摘要】 聚苯胺（PANI）凭借良好的化学稳定性、导电性和高的赝电容储能特性及成本低廉等优点，成为一种极具发展潜力的超级电容器电极材料。尤其是一维纳米结构的聚苯胺纤维材料，除了具有其他纳米结构的高比表面积的特点之外，还具有高长径比、高孔隙率及优良导电性能，因而在超级电容器领域具有重要的研究价值。本文采用新颖的界面聚合法制备聚苯胺纳米纤维材料，系统研究并优化了界面聚合工艺技术条件；研究了聚苯胺纳米纤维电极在硫酸水溶液中的电化学电容特性；对聚苯胺纳米纤维材料进行了锂盐掺杂，研究了所得锂盐掺杂态聚苯胺电极在有机电解液中的电化学电容特性；在此基础上，构造了一种新颖的锂盐掺杂态聚苯胺纳米纤维／自制活性炭混合电容器。获得的主要研究成果和结论如下：（1）采用优化后界面聚合工艺条件可制备出尺寸均一、具有良好纳米纤维形貌的聚苯胺材料，纳米纤维直径在50～100nm之间、长度为500nm至几微米不等；有效解决了聚合过程中出现“拥挤效应”导致界面聚合法产率不高的问题，将聚苯胺纳米纤维的产率由10％提高到35％。（2）在硫酸水溶液电解液中，所制备的聚苯胺纳米纤维电极具有较高的比电容、较好的功率特性和循环性能，5mA放电电流下单电极比电容可达317F╱g，放电电流从5mA提高到20mA后电极容量只下降5％，500次充放电循环后电极容量衰减小于4％；与采用传统化学聚合法制备的不规则颗粒状结构的聚苯胺电极（放电电流从5mA提高到20mA后电极容量下降11％、500次充放电循环后电极容量衰减33％）相比，聚苯胺纳米纤维在微观形貌与结构上的优势得到充分体现。（3）发现锂盐对本征态聚苯胺材料可进行充分有效的类似于无机酸的掺杂，而对已经经过酸掺杂的聚苯胺材料可能仅起一个有限的补充掺杂的作用。锂盐掺杂可将聚苯胺纳米纤维材料在1M LiPF₆有机电解液中的比电容值由49.75F╱g提高到128.05F╱g，同时有效改善材料的循环稳定性能（500次充放电循环的容量衰减由70％减少到30％）和电性能；但是，还存在电压降过大、工作电位上限不够高、有效储能电位区间过窄等问题。（4）采用所制备的锂盐掺杂态聚苯胺纳米纤维材料和自制活性炭材料构造了一种新颖的混合电容器，通过对比研究认为Et₄NBF₄╱PC有机溶液比含LiPF₆的有机溶液更适合作为这种混合电容器的电解液；该混合电容器与聚苯胺／聚苯胺对称型相比，可以在保持比容量不降低的前提下，有效储能电位区间由0～1V扩大到0～2V，工作电位上限由2.0V提高到2.5V，同时放电电压降大大减小，循环性能得到进一步改善。更多还原

【Abstract】 Polyaniline （PANI） has enormous development ability as a kind of electrode material of supercapacitor, because of its desirable chemical stability, good conductivity and high faradic pseudo capacitance, as well as low cost advantage. Especially PANI material with one-dimensional nano-structure, in addition to other nano-structure’s high specific surface features, also with high long-diameter ratio, high porosity and excellent electrical properties, thus has important research value in the field of supercapacitor.In this paper, PANI nanofiber material was prepared by a novel method of interfacial polymerization. The interfacial polymerization’s conditions were investigated and optimized systematically; the behaviors of acquired PANI nanofiber material’s electrochemical capacitance in H2SO4 aqueous solution were studied; the electrochemical and capacitive characteristics of the PANI nanofiber of lithium salt doping state in organic electrolyte were studied. On the basis, a novel hybrid capacitor based on the PANI nanofiber of lithium salt doping state and homemade activated carbon was constructed. The main research results and conclusions are as follows:（1） The optimal interfacial polymerization process can prepare Polyaniline nanofiber material with uniform size and good morphology. The material’s average diameter is about 50-100 nm and length ranges from 500 nm up to several micrometers. Meanwhile, the process effectively solves the problem brought by crowding effect and improves the Polyaniline nanofiber’ yield from 10% to 35%.（2） In H₂SO₄ aqueous solution, acquired PANI nanofiber material can maintain high specific capacitance, good power characteristic and cycle performance. Its single-electrode specific capacitance can reach as high as 317 F/g in discharge current of 5mA, reducing by 5% when discharge current increases from 5mA to 20mA, and the degradation of capacitance is within only 4% during 500 charge-discharge cycles; compared with PANI material with irregular granular morphology prepared by conventional chemical polymerization （electrode capacitance reduces by 11% when discharge current increases from 5mA to 20mA and degradation of capacitance is about 33% during 500 charge-discharge cycles）, the advantages of PANI nanofiber material in morphology and structure are fully performed.（3） Lithium salt can dope PANI material in non-doping state fully and effectively, which is similar to the doping of inorganic acid, and may play only a limited and added doping role to PANI material having been doped by acid. Lithium doping increases PANI nanofiber material’s capacitance in 1M LiPF₆ organic electrolyte from 49.75F/g to 128.05F/g, and effectively improves recycling stability （degradation of capacitance is within only 30% compared with 70% during 500 charge-discharge cycles） and electricity performance. However, several problems exist, such as excessive voltage drop, low potential ceiling and narrow effective energy storage’s potential range.（4） A novel hybrid capacitor based on the PANI nanofiber of lithium salt doping state and homemade activated carbon is constructed. It shows that Et₄NBF₄/PC organic solution is more suitable for the organic electrolyte of the hybrid capacitor compared with organic solution concluding LiPF₆. The effective energy storage’s potential range widens from 0-1V to 0-2V and potential ceiling increases from 2.0V to 2.5V under the circumstance of constant capacity, compared with the PANI/PANI symmetric capacitor. At the same time, the discharge voltage drop decreases greatly and cycle performance further improves.更多还原