控制合成聚吡咯和多孔炭的研究

发布时间：2018-03-24 03:24

  本文选题：微/纳米结构　切入点：聚吡咯　出处：《湖南大学》2016年硕士论文

【摘要】：超级电容器作为一种新型储能元件,因其高的功率密度、高的倍率性能以及长的使用寿命等特性,引起了国内外的广泛关注。电极材料是决定超级电容器性能的关键因素之一,超级电容器的电极材料可分为碳材料、过渡金属氧化物材料以及导电高分子材料。其中,导电高分子聚吡咯(PPy)因具有合成简单、环境稳定性好以及电导率高等优异的特性而引起了人们深入的研究。近年来,具有微/纳米结构的PPy材料因同时具有导电聚合物本身的性质和微/纳米尺寸特性而逐渐成为其发展的主导方向,但目前报道的微/纳米结构PPy以零维(0D)或一维(1D)结构居多,二维(2D)的PPy微/纳米结构还较少见。在碳材料中,多孔炭材料因其高比表面积、优异的物理化学稳定性以及成本较低等优点而成为了超级电容器最常用的电极材料。多孔炭材料一般分为活性炭、炭气凝胶、模板碳等,影响多孔炭材料电化学性能的主要因素有:比表面积、孔径分布、孔径长度、表面性质、导电性以及微观形貌等。目前,如何协调利用好上述影响因素制备出具有高电化学性能的多孔炭电极材料也成为了当前超级电容器研究的一个重要内容。基于以上探讨,本文主要控制合成2D微/纳米结构PPy以及控制多孔炭材料的微观形貌、表面性质和导电性能,来制备具有高电化学性能的多孔炭材料。主要研究内容如下:(1)通过采用软模板法,使用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)与吡咯单体形成胶束,以丙酸(PA)为掺杂剂,过硫酸铵(APS)为氧化剂,制备出2D的微/纳米结构PPy。采用SEM、TEM、AFM、FT-TR、XRD、TG、DLS、CV及EIS等分析手段对其形貌、结构以及电化学性能进行了表征,并探讨了CTAB浓度的变化对合成微/纳米结构PPy的形貌的影响。结果表明:当CTAB、PA及吡咯的浓度分别为0.017 M、3.1 M和0.028 M时,制备出的PPy的形貌最规整,为由粒径约为60 nm的PPy纳米粒子紧密堆积而成的双层菱形片状结构;此菱形片状结构PPy为掺杂态非晶结构PPy,具有优良的热稳定性及电化学活性。(2)以花瓣球形聚苯胺(PANI)为前驱体,经炭化和KOH活化制备出球形结构的活性炭。采用SEM、TEM、Raman、XRD、低温N2吸脱附以及XPS等分析手段对活性炭的形貌、结构和元素组成进行了表征,并探讨了炭化温度、活化温度及KOH用量对活性炭电化学性能的影响。结果表明:炭化和活化温度分别为750℃和850℃、KOH与炭化样的质量比为4时,获得的活性炭为直径约2μm的球形粒子,其比表面积高达2496.6 m2/g,并具有合适的多级孔结构分布。当电流密度为0.5 A/g时,合成的活性炭比电容值高达247 F/g;并且当电流密度增大到20 A/g时,比电容量仍有182 F/g,表现出优良的倍率性能;在电流密度为10 A/g的条件下,经1000次恒电流充放电循环后,其比电容量保持率为102%。(3)通过直接炭化金属-有机配位聚合物/多壁碳纳米管(MOCP/MWCNT)复合物制备了高氮含量的氮掺杂多孔炭/MWCNT复合多孔炭材料,其中,MOCP是通过4,4'-联吡啶(BPD)与Fe Cl3发生配位络合反应而形成的。采用SEM、TEM、XRD、Raman、低温N2吸脱附以及XPS等分析手段对其形貌、结构和元素组成进行了表征,并探讨了投料比及炭化温度对氮掺杂多孔炭/MWCNT电化学性能的影响。结果表明:当质量比MWCNT/BPD=1:15、摩尔比BPD/Fe Cl3=1:1、炭化温度为650℃时,制得的氮掺杂多孔炭/MWCNT具有合适的三维多级孔结构,比表面积可达1023 m2/g,并具有高达10.71 at.%的氮含量。当电流密度为0.5 A/g时,其比电容值达到295.2 F/g;当电流密度增加为20 A/g时,其比电容值仍可保持为186 F/g,体现了优异的倍率性能;在高电流密度为10 A/g的条件下进行2000次循环,其比电容值无衰减,体现了优异的循环稳定性。
[Abstract]:Supercapacitor is a new energy storage device, because of its high power density, high rate performance and long service life and other characteristics, has attracted wide attention both at home and abroad. The electrode material is one of the key factors influencing the performance of supercapacitor, electrode material for super capacitor can be divided into carbon materials, transition the metal oxide materials and conductive polymer materials. The conductive polymer polypyrrole (PPy) because of its simple synthesis, environmental stability and high electrical conductivity and excellent properties attracted further research. In recent years, with the micro / nano structure of PPy materials because of its properties of conductive polymer itself and micro / nano size and characteristics gradually become the dominant direction of its development, but the current coverage of the micro / nano structure of PPy (0D) with zero dimensional or one-dimensional (1D) structure are two-dimensional (2D) PPy micro / nano structure is also relatively rare. Carbon materials, porous carbon materials because of its advantages of high surface area, excellent physical and chemical stability and low cost has become the most commonly used electrode materials for supercapacitor. Porous carbon materials are generally divided into activated carbon, carbon aerogels, carbon template, main factors affecting the electrochemical performance of porous carbon materials are: the surface area, pore size distribution, pore length, surface properties, electrical conductivity and microstructure. At present, how to coordinate the use of the influence factors of preparation of porous carbon electrode material with high electrochemical performance has become an important part of the research of super capacitor. Based on the above discussion, this paper mainly control the synthesis of 2D the micro / nano structure PPy and porous carbon materials microstructure, surface properties and conductivity to porous carbon materials were prepared with high electrochemical performance. The main research contents are as follows: (1) the 鐢ㄨ蒋妯℃澘娉，

本文编号：1656507