电解液添加剂对柠檬酸盐基炭材料的超电容性能影响研究
发布时间：2018-10-24 08:31
【摘要】：本论文主要利用模板炭化法制备一系列具有不同内部结构和电化学性能的纳米多孔炭材料,考察了炭化温度和模板类型对炭材料性能的影响。在此基础上,通过引入一系列不同的氧化还原添加剂进一步提高超级电容器电化学性能,对其反应机理进行详细的研究。具体内容如下:1.引入氧化还原添加剂钙试剂羧酸钠(简称CS)到KOH电解质中提高超级电容器的电化学性能。实验中,首先在800 ℃下直接炭化柠檬酸钾得到Carbon-800样品。然后在三电极系统中测量电化学性能,以6 mol L-1 KOH为电解液,测得该样品在3 Ag-1 电流密度下的质量比电容为128 F g-1。为了进一步提升超级超级电容器的电容性能,在KOH电解液中引入一系列浓度的钙试剂羧酸钠。结果表明,当6 mol L-1 KOH电解液中加入15 mmol L-1钙试剂羧酸钠,Carbon-800-15样品在3Ag-1的电流密度下显示出了较高的质量比电容237F g-1,是Carbon-800样品质量比电容的2.1倍。除此之外,在二电极系统中,Carbon-800-15样品在1.5 kW kg-1的功率密度下能量密度高达11.4 Wh kg-1,远大于在相同功率密度Carbon-800样品的能量密度7.3 Wh kg-1。提高的比电容主要来源于电极/电解液表面质子与电子的快速氧化还原反应。由此可见,钙试剂羧酸钠在提高超级电容器的性能方面具有潜在的应用价值。2.以柠檬酸三钠为唯一碳源在800 ℃下炭化,制备新型的二维非晶炭材料(样品命名为SC-blank),该样品比表面积和孔隙体积分别高达1015.8 m2 g-1和2.0 m3 g-1。此外,我们应用了一种炭化和石墨化同步的方法合成部分石墨化炭材料。首先,在800 ℃下炭化柠檬酸三钠和硝酸镍的混合物(质量比为7:1),得到SC-7:1样品,由于石墨化程度的增加促使其比表面积减少到682.8 m2 g-1,质量比电容也有所减小,但该样品具有了更好的倍率性能。更为重要的是,引入一定量的氧化还原添加剂对磺基苯偶氮变色酸钠(简称SAA)到KOH电解液中提高超级电容器的电化学性能。当电流密度为3 A g-1时,SC-blank样品在KOH和对磺基苯偶氮变色酸钠混合电解液中的质量比电容高达200 F g-1,相对于在传统KOH电解液中测得的比电容(66 Fg-1)有了很大幅度的提高。总之,对磺基苯偶氮变色酸钠是一种可以有效提高电容的氧化还原添加剂。3.引入一种简单高效的氧化还原添加剂邻苯二酚紫(简称PCV)到不同的水质电解液(H2SO4、Na2SO4、KOH)中提高超级电容器的电化学性能,这种性能的提升主要来源于电子和质子在电极/电解液界面快速的氧化还原反应。实验表明邻苯二酚紫的浓度对超级电容器电化学性能具有重要的影响。在二电极系统中,当把0.006 mol的邻苯二酚紫加入到1mol L-1 H2SO4电解液中,超级电容器的电容达到200 F g-1,其是初始质量比电容的2.6倍。此外,对应的能量密度也高达28Wh kg-1 (增加了两倍)。邻苯二酚紫也被进一步加入到Na2SO4和KOH介质中,其电容和能量密度也都有显著的提高,进一步证明邻苯二酚紫的高效性和普适性。实验结果表明具有突出电化学可逆性、良好普适性和较高溶解度的邻苯二酚紫是一种非常高效的氧化还原添加剂。
[Abstract]:In this paper, a series of nano-porous carbon materials with different internal structure and electrochemical properties were prepared by template carbonization, and the influence of carbonization temperature and template type on the properties of carbon materials was investigated. On this basis, the electrochemical performance of super capacitor is further improved by introducing a series of different redox additives, and the reaction mechanism is studied in detail. The specific content is as follows: 1. The electrochemical performance of the super capacitor is improved by the introduction of the redox additive calcium reagent caustic soda (CS) into the KOH electrolyte. In the experiment, potassium citrate was first carbonized at 800 鈩，
本文编号：2290871
[Abstract]:In this paper, a series of nano-porous carbon materials with different internal structure and electrochemical properties were prepared by template carbonization, and the influence of carbonization temperature and template type on the properties of carbon materials was investigated. On this basis, the electrochemical performance of super capacitor is further improved by introducing a series of different redox additives, and the reaction mechanism is studied in detail. The specific content is as follows: 1. The electrochemical performance of the super capacitor is improved by the introduction of the redox additive calcium reagent caustic soda (CS) into the KOH electrolyte. In the experiment, potassium citrate was first carbonized at 800 鈩，
本文编号：2290871
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