摘 要:采用化学水热法制得C、C-Mn3O4、凹凸棒粘土-活性炭-Mn3O4(C-Mn3O4- Att)复合材料用于超级电容器材料。以该复合材料为活性物质制成电极,采用循环伏安、恒流充放电、交流阻抗等电化学方法考察其电化学性能。循环伏安分析表明,电极在0.5mol·L- 1Na2SO4溶液中,在0~0.8V(vs.SCE) 电压范围内,碳电极、C-Mn3O4以及C-Mn3O4- Att电极,均表现出良好的电容性能;其中,电极加入Mn3O4后,CV图中出现了明显的氧化还原峰,这说明加入Mn3O4对电极的电化学性能有所改善。在0.2A·g - 1电流密度下,三电极的最佳电位范围为0~0.8V,电容器的充放电性能良好。加入Mn3O4后,C-Mn3O4的实际功率得到了改善,为0.0755 W.g-1达到最大。通过分析可知,电极在负载3.5%凹土时,C-Mn3O4-Att电极电容器在电压范围为0~0.8V,在0.2A·g-1电流密度下,比容量为158.5 F·g-1,储能密度为50.72 Ws·g-1,电极的比容量和储能密度均达到最大。电极在加入Mn3O4、Att后相比纯碳电极阻抗曲线直线斜率较大,且C-Mn3O4-Att电极最佳,C-Mn3O4电极次之,C 电极最小,说明加入Mn3O4、Att后,电学性能有所改善。总的来说,电极在加入Mn3O4电化学性能得到一定改善,而在掺入凹土后,电化学性质改善的并不明显。53150
毕业论文关键词: 超级电容器、C-Mn3O4、凹凸棒粘土,循环伏安,充放电,比电容
Abstract:Activated carbon (C)、Mn3O4 modified Activated carbon (C-Mn3O4) and Attapulgite modified C-Mn3O4 (C-Mn3O4-Att) composite materials used as electrode materials for supercapacitors were synthesized by hydro-thermal method. Electrochemical properties of the resultant were investigated by charge/discharge,AC impedance and cyclic voltammetry (CV) method using a three-electrode system, in which working electrode was made from the product. Based on CV (vs.SCE) results, the working voltage for C、C-Mn3O4 and C-Mn3O4-Att composites with ideal capacitor behavior were 0-0.8 V in 0.5mol·L- 1 Na2SO4, respectively. At 0.2A·g - 1current density, different potentials were applied to obtain the optimum cell voltage. It was found that the optimum cell voltage for C, C-Mn3O4, and C-Mn3O4- Att were all at 0-0.8V. From the CV curves, a clear redox peak was observed after Mn3O4 was added into active carbon, indicating that adding Mn3O4 can improved its electrochemical properties. By comparison, the actual power of C-Mn3O4 reached to 0.0755 Wg-1 and it is the maximum among these three electrode materials. We got the highest specific capacity and energy density when adding 3.5% attapulgite to that of C-Mn3O4-, they were 158.5 F·g-1, 50.72 Ws·g-1, respectively. From electrode impedance curve, the slope of C-Mn3O4-Att is the largest, and the C-Mn3O4 electrode followed, C electrode is the minimal. Overall, the addition of Mn3O4 to activated carbon can improve its electrochemical performance to some extent, whereas the adding of attapulgite can not improve the electrochemical properties obviously.
Key words: Supercapacito, C-Mn3O4, Attapulgite, Cyclic voltamper, Specific capacitance
目 录
1 引言 4
2 实验部分 5
2.1 仪器和试剂 5
2.2 复合材料的制备 5
2.2.1 C-Mn3O4复合材料的制备 5
2.2.2 C-Mn3O4-Att复合材料的制备 5
2.3 材料表征 5
2.3.1 粉末X射线衍射 5
2.3.2 扫射电镜形貌分析 6
2.4 电极材料的制备