【作者】 黄铮铮；

【导师】 刘恩辉；

【作者基本信息】 湘潭大学 ， 应用化学， 2011， 硕士

【摘要】 炭材料原料易得、成本低并且具有独特的物理化学性质,因而在气体储藏、催化化学以及污水处理等方面有广泛的应用,特别是作为电极材料方面,炭材料成为研究的热点。本文以氧化聚合所得聚苯胺(PANI)为前躯体,通过炭化活化,制备出应用于超级电容器及锂离子电池负极的掺杂炭材料,研究了其电化学性能。主要内容如下：1.以氧化聚合所得聚苯胺颗粒为前躯体,通过炭化与水蒸气活化,制备出应用于超级电容器的掺杂活性炭。通过正交试验探讨了各因素对材料性能的影响,确定了最佳工艺条件：炭化温度为700℃,活化温度为850℃,活化时间为2 h。该条件下制备的活性炭比表面积为584 m2/g,具有微孔结构,其中84%的氮原子以具有电化学活性的吡啶氮和吡咯氮形式存在。其比电容为170 F/g,并且循环性能良好,2000次循环后,比电容仍保持为起始容量的96.5%。2.采用自组装方法制备聚苯胺纳米管,通过条件实验讨论了各组分浓度对产品形貌的影响,确定了最佳反应介质为：含0.4 mol/L醋酸与1.0 mol/L甲醇的混合溶液。其分子结构与形貌随时间的演变表明纳米管通过自卷曲过程形成。以该聚苯胺纳米管为前躯体,通过炭化与氧气活化,制备出掺杂活性碳纳米管,将其应用于超级电容器。通过正交试验探讨了各因素对材料性能的影响,确定了制备炭材料的最佳工艺：炭化温度为700℃,炭化时间为1h,活化温度为450℃,活化时间为1.5 h。该条件下制备的碳纳米管比表面积为618.91 m2/g,微孔孔容为0.2213 cm3/g,介孔孔容为0.2581 cm3/g。其比电容达到220 F/g,并且具有良好的循环性能,在8000次循环后,其比电容还保持为初始循环比电容的98%。3.将制备的碳纳米管用作锂离子电池负极材料,炭化样与活化样的首次放电容量分别为1370和880 mAh/g,首次充电容量分别为907和404 mAh/g,均高于石墨的理论容量。随着充放电循环的进行,炭化样的容量逐渐衰减,而活化样品的容量在9个循坏后趋于稳定,20次循环后,活化样品放电容量仍保持为728mAh/g。更多还原

【Abstract】 Due to the advantage of richness in raw materials, low cost and special physico-chemical properties, carbon materials have been widely used in many fields such as storage of gas, purifying sewage and catalyst, especially in electrode materials. Thus carbon materials have attracted more and more attention from scientists in electrode material field. In this paper, doped carbon materials have been prepared from polyaniline (PANI) particles and polyaniline nanotubes obtained via still reaction by carbonization and activation. These carbon materials have been used for electrode materials of supercapacitors and lithium ion batteries. Their electrochemical performances were studied. The major contents of the paper are as follows:1. Doped carbons have been prepared from polyaniline by steam activation for supercapacitors. Orthogonal experiments were carried out to study the influence of conditions and find out the optimum technological condition:the carbonization temperature was 700℃, the activation temperature was 850℃and the activation time was 2 h. The carbon has a BET surface area of 584 m2/g and presents micropore structure.84% of the nitrogen atoms in this marerial exist in forms of pyridinic and pyrrolic. The specific capacitance is 170 F/g. The cycle performance is also satisfactory. The specific capacitance retained 96.5% of original specific capacitance after 2000 cycles.2. Polyaniline nanotubes were prepared by the self-assembly method. Conditional experiments were carried out to study the influence of component concentration and find out the optimum media—the mixed solution of 0.4 mol/L acetic acid and 1.0 mol/L methanol. FTIR spectra and SEM images of PANI intermediates demonstrate that PANI nanotubes form through a self-curling behavior. Doped carbon nanotubes have been prepared from these polyaniline nanotubes by carbonization and oxygen activation for supercapacitors. Orthogonal experiments were employed to study the influence of conditions and find out the optimum technological condition:the carbonization temperature was 700℃, the carbonization time was 1 h, the activation temperature was 450℃, the activation time was 1.5 h. The carbon has a BET surface area of 584 m2/g and a micropore volume of 0.2213 cm3/g, a mesopore volume of 0.2581 cm3/g. The specific capacitance is 220 F/g. The cycle performance is also satisfactory. The specific capacitance retained 98% of original specific capacitance after 8000 cycles. 3. The electrochemical performance of the obtained materials as the anode materials of lithium ion batteries has been studied. The first discharge capacities are 1370 and 880 mAh/g, respectively. The first charge capacities are 907 and 404 mAh/g, respectively. Both of them have the capacities higher than graphite. The capacity of unactivated sample takes on a gradual drop trend with cycle numbers. As for activated sample, it capacity-loss gets effective control after 9 cycles, even after 20 cycles its discharge capacity remains 728 mAh/g.更多还原