论文总字数：15057字

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^{- 1}Na₂SO₄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。

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 ^{- 1}current 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 6

2.5 电化学测试方法 6

3 结果与讨论 6

3.1 XRD分析 6

3.2 扫射电镜图形 7

3.3 循环伏安测试 8

3.4 恒电流充放电测试 12

3.5 电化学阻抗测试 19

结 论 22

参 考 文 献 23

致 谢 25

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