【作者】 史军军；

【导师】 范国樑；

【作者基本信息】 天津大学 ， 材料学， 2009， 硕士

【摘要】 超级电容器是一种性能介于传统电容器和化学电池之间的新型储能元件,具有更高的能量密度和更大的功率密度。目前,对超级电容器的研究主要集中在高性能的电极材料的制备上。本文主要制备了纳米结构的聚苯胺(Polyaniline, PANI)以及聚苯胺/碳基复合材料,研究了它们的制备工艺和电化学性能,并用傅立叶转换红外光谱、X射线衍射、X射线光电子能谱、透射电子显微镜、扫描电子显微镜、比表面积、循环伏安、交流阻抗、恒电流充放电分析等对其进行了表征,得到以下结论:(1)采用乙醇作溶剂制备得到了PANI纳米微球,其直径在50~200 nm之间,为乙醇掺杂的翠绿亚胺态,具有一定的结晶性能;相对于传统方法制备的PANI块体材料有着更好的电化学活性,单电极放电比容量可以达到630 F·g-1,比块体PANI提高了40%左右;循环稳定性也相对提高,充放电循环1000次之后仍能保持在220 F·g-1。(2)采用原位聚合法将聚苯胺均匀包覆在碳纳米管(Carbon Nanotubes, CNTs)表面,制备得到核壳结构的PANI/CNTs复合材料,CNTs表面的PANI壳层厚度约为50 nm;复合材料有着良好的法拉第赝电容特性,单电极放电比容量可以达到458 F·g-1,远远高于所用纯CNTs (约31 F·g-1)和块体PANI (420 F·g-1)的比容量,其循环稳定性相对于块体PANI也有所提高。(3)以盐酸掺杂的PANI为前驱体在750℃煅烧制备得到了高活性的多孔碳材料(Highly Porous Carbon Materials, HPC),其比表面积可以达到1772 m2·g-1,具有良好的双电层电容性能,在充放电过程中有较高的充放电效率(99.8%)和循环稳定性,单电极放电比容量在电流密度为1 mA·cm-2时可以达到327.4 F·g-1,经过1000次充放电循环后其衰减量仅为3.5%。(4)以多孔碳为基体制备得到了PANI/HPC复合材料,属于二维纳米结构范畴,有着较大的比表面积、较高的电化学活性和充放电容量,在电流密度为10mA·cm-2时的单电极放电比容量为519.8 F·g-1;在1 mol·L-1的H2SO4水溶液中,相对于Hg/Hg2SO4参比电极的合适充放电电位窗口为-600 mV~600 mV。更多还原

【Abstract】 Supercapacitor had been recognized as a new kind of electrochemical energy storage device, which provided performances between the rechargeable batteries and the typical dielectric capacitor. It had received great attention due to its high power density and energy density. Most of the studies reported recently concentrated on the preparation of high performance electrode materials.In this paper, nanostructured polyaniline (PANI) and polyaniline/carbon-base composites were synthesized. The materials’preparation and electrochemical performance were studied systematically by FT-IR, XRD, XPS, TGA, TEM, SEM, BET, CV test, EIS and galvannostatic charge/discharge. The main results were as follows:(1) The PANI nanospheres with diameter of 50~200 nm were prepared by synthesizing within ethanol solvent. FT-IR, XPS spectra and XRD pattern indicated that the PANI was emeraldine state doped with C2H5OH and crystallizable. In addition, the electrochemical analysis demonstrated that the PANI nanospheres showed an improved performance as supercapacitor. The specific capacitance of the PANI nanospheres was 630 F·g-1, 40% higher than the traditional PANI block materials. After 1000 charge/discharge cycles, the specific capacitance could also hold 220 F·g-1. The PANI nanospheres exhibited highly cyclic stability.(2) The polyaniline coated multi-walled carbon nanotubes (PANI/CNTs) composites were synthesized by in situ polymerization. Analysis results showed that the thickness of PANI layer on the surface of CNTs was ca. 50 nm. The composites had typical Faraday capacitor characteristics. The specific capacitance of the obtained composite materials was about 305.3 F·g-1 whereas the specific capacitance of the pure CNTs (31F·g-1) at the same conditions. The cyclic stability was higher than block materials.(3) The highly porous carbon materials (HPC) with highly electrochemical performance was calcined at 750℃through the precursor substance which HCl doped PANI. The specific surface area of HPC was 1772 m2·g-1. The HPC had excellent electric double-layer capacitance, highly coulombic efficiency (99.8%) in charge/discharge and cyclic stability. The specific capacitance was 327.4 F·g-1 at the electric current density of 1 mA·cm-2. The decrease of specific capacitance was only 3.5% after 1000 charge/discharge cycles.(4) The PANI/HPC composites were synthesized with the base of HPC. The 2-dimensional composites possessed large specific surface area, improved electrochemical performance and high specific capacitance. At the electric current density of 10 mA·cm-2, the discharge specific capacitance of the obtained composite materials was about 519.8F·g-1. The EIS test indicated that the working potential window of the obtained composite material electrode was -600 mV~600 mV vs. Hg/Hg2SO4 in 1 mol·L-1 H2SO4.更多还原