电化学电容器电极材料氧化锰及其复合材料的制备与性能研究

发布时间：2018-03-04 23:20

本文选题：电化学电容器　切入点：MnO_2　出处：《上海师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：超级电容器又称为电化学电容器,作为新型的储能器件其具有较多的优点:能够快速的充放电,较高的功率密度和良好的循环稳定性等。电化学电容器按储能机理可分为碳基电极材料的双电层电容器和具有氧化还原反应电极材料的赝电容两类。决定电化学电容器性能的关键因素之一是电极材料的使用,碳基材料具有较好的导电性和循环稳定性,但其能量密度较低;赝电容电极材料的研究主要集中在具有商业应用的过渡金属氧化物上,其具有较高的理论比电容,然而单一的过渡金属氧化物导电性较差。为了改善这些不足,本论文利用水热法和电化学沉积的方法合成了MnO_2/C复合材料以及导电性良好的具有新颖三维结构的锰基混合过渡金属氧化物材料(MTMOs),利用协同作用促进材料的电化学性能。论文中的主要内容概括如下:1、采用廉价易得的三聚氰胺为原材料合成三聚氰胺甲醛树脂球,氮气气氛下对其进行碳化得到富氮的碳纳米小球。2、在简单有效的水热反应中,利用碳纳米球还原KMnO_4得到MnO_2/C复合材料,并通过调节反应条件得到最佳性能的纳米棒状MnO_2/碳球复合材料。以1mol L-1NaSO_4为电解液,0.1A g-1电流密度下其比电容值为305.6F g-1,并且该复合材料具有较好的循环稳定性,1000次循环测试后其性能仍保持88.04%。3、在水热反应的基础上合成出纳米管状的MnCo_2O_(4.5)电极材料,然后通过电化学沉积的方法在泡沫镍片上得到新颖三维结构的MnCo_2O_(4.5)@MnCo_2O_(4.5)电极材料。并通过改变电沉积时间,探讨了20圈,50圈和80圈沉积条件下的电极材料的电化学性能。发现在沉积50圈时材料性能最佳,1A g-1的电流密度下比电容达到1580F g-1,远高于水热条件下得到的MnCo_2O_(4.5)和沉积20圈、80圈条件下电极材料的性能。此外,沉积50圈的材料也表现出较好的倍率性能,当电流密度增大10倍时,其比电容仍保持初始值的52.2%。通过2000次的循环稳定性测试,发现三维结构的MnCo_2O_(4.5)@MnCo_2O_(4.5)-50电极材料仍能保持初始比电容的98.2%,说明合成的三维结构材料具有超长的使用寿命。
[Abstract]:Supercapacitors, also called electrochemical capacitors, as a new type of energy storage devices, have many advantages: they can charge and discharge rapidly. Electrochemical capacitors can be divided into two categories according to the energy storage mechanism: double layer capacitors with carbon-based electrode materials and pseudo-capacitors with redox electrode materials. One of the key factors in the performance of capacitors is the use of electrode materials, Carbon based materials have good electrical conductivity and cycle stability, but their energy density is low, and the study of pseudo-capacitance electrode materials is mainly focused on transition metal oxides with commercial applications, and has a higher theoretical specific capacitance. However, a single transition metal oxide has poor conductivity. In order to improve these deficiencies, In this paper, MnO_2/C composites and novel three dimensional manganese based mixed transition metal oxide materials with good electrical conductivity were synthesized by hydrothermal method and electrochemical deposition. The synergistic effect was used to promote the electrochemical properties of the materials. Performance. The main contents of this paper are summarized as follows: 1. Melamine formaldehyde resin spheres are synthesized by using cheap and easily available melamine as raw material. The carbon nanospheres were carbonized in nitrogen atmosphere to obtain nitrogen-rich carbon nanoparticles. In the simple and effective hydrothermal reaction, the KMnO_4 composites were reduced by carbon nanospheres to obtain MnO_2/C composites. By adjusting the reaction conditions, the best properties of nano-rod-shaped MnO_2/ carbon ball composites were obtained. The specific capacitance of the composite was 305.6 F g-1 at the current density of 0.1A g ~ (-1) with 1 mol L ~ (-1) NaSO4 as electrolyte, and the composite had good cycling stability 1000 times. After the ring was tested, the properties remained 88.040.3. on the basis of hydrothermal reaction, the nanoscale MnCo _ 2o _ 2O _ 5) electrode material was synthesized. Then, by electrochemical deposition method, a novel three-dimensional MnCoS _ 2O _ O _ (4. 5) electrode material was obtained on the nickel foam wafer, and the electrode material was obtained by changing the electrodeposition time. The electrochemical properties of electrode materials were studied under the conditions of 20 cycles and 50 cycles and 80 circles. It was found that the optimum material performance at 50 cycles was 1580F g -1 at current density, which was much higher than the MnCo2OS 4.5) and sedimentation at hydrothermal conditions. Properties of electrode materials at 20 laps and 80 laps. In addition, The material deposited in 50 cycles also showed good rate performance. When the current density increased 10 times, the specific capacitance remained 52.2% of the initial value. It is found that the three-dimensional structure of MnCo_2O_(4.5)@MnCo_2O_(4.5)-50 electrode material can still maintain the initial specific capacitance of 98.2. It shows that the synthesized three-dimensional structure material has a long service life.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ137.12;TB33;TM53

【参考文献】