| 论文中文题名： | 镍掺杂二氧化锰/导电聚合物复合电极材料的制备及性能研究 |
| 姓名： | |
| 学号： | 17211203031 |
| 保密级别： | 公开 |
| 论文语种： | chi |
| 学生类型： | 工程硕士 |
| 学位年度： | 2020 |
| 培养单位： | 西安科技大学 |
| 院系： | |
| 专业： | |
| 研究方向： | 功能材料 |
| 第一导师姓名： | |
| 第一导师单位： | |
| 论文外文题名： | Preparation and Properties of Nickel-doped Manganese Dioxide/Conductive Polymer Composite Electrode Materials |
| 论文中文关键词： | |
| 论文外文关键词： | Supercapacitors ; Manganese Dioxide ; PANi-co-PPy ; Polypyrrole ; Sodium Lignosulfonate ; Electrochemical |
| 论文中文摘要： |
二氧化锰因其储源丰富、价格低廉、环境友好并且理论比电容高而在超级电容器领域备受关注。然而，导电性、倍率性能以及循环稳定性都较差而严重限制了其应用。为了提高二氧化锰的电化学性能，本文通过对二氧化锰进行改性，分别采用溶胶-凝胶法、原位聚合法和原位凝胶法，制备了三种系列MnO2基电极材料，并通过红外光谱（FT-IR）、拉曼光谱（Raman）、X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、循环伏安（CV）、恒流充放电（GCD）和交流阻抗（EIS）等手段对材料组成结构和电化学性能进行测试。 溶胶-凝胶法制备镍掺杂二氧化锰(Ni-MnO2)，结果表明掺Ni前后MnO2的晶型结构均为γ-MnO2，当Ni、Mn的摩尔比为0.03:1时，样品NMO-3的粒径约60 nm，比表面积为82 m2/g。该样品在2 mV/s扫描速率时的比电容达到最大值221.39 F/g，比未掺Ni的MnO2提高了54.97%。电流密度为0.5 A/g时，样品NMO-3的比电容为138.07 F/g。充放电循环2000次后，其比电容保持率为75.02%。 原位聚合法制备镍掺杂二氧化锰/(苯胺-吡咯)共聚物(Ni-MnO2/PANi-co-PPy)复合材料。结果表明PANi-co-PPy层均匀包覆在Ni-MnO2表面，形成核壳结构，包覆层厚度约100 nm。当Ni-MnO2与苯胺/吡咯混合单体质量比为1:5时，样品NMP-5在2 mV/s扫描速率时的比电容高达445.49 F/g，比Ni-MnO2的比电容高出2倍。电流密度为0.5 A/g时，样品NMP-5的比电容为385.67 F/g。经5000次循环充放电后，其比电容衰减至初始值的61.65%。 原位凝胶法制备二氧化锰/聚吡咯/木质素磺酸钠（MnO2/PPy/SLS）三元复合材料，结果表明添加MnO2、SLS组分并不能对PPy的化学结构产生明显影响。未添加SLS时，PPy在MnO2微球表面有序生长，形成直径约5 μm的海胆结构，添加SLS后，复合材料的形貌变为纳米级球型颗粒，平均粒径约100 nm。当Mn与吡咯单体的摩尔比为1:5，且SLS与吡咯单体的质量比为10%时，样品MPS-5-10%在2 mV/s扫描速率时的比电容为482.86 F/g。电流密度为0.2 A/g时，样品MPS-5-10%的比电容高达665.80 F/g。经2000次循环充放电后，其比电容衰减至初始值的71.69%。 |
| 论文外文摘要： |
Manganese dioxide has attracted much attention in the field of supercapacitors because of its abundant sources, low prices, environmental friendliness, and higher theoretical capacity. However, poor conductivity, rate performance, and cycle stability severely limit its application. In order to improve the electrochemical performance of MnO2, three series of MnO2-based electrode materials are synthesized by modifying MnO2 with using sol-gel method, in-situ polymerization method and in-situ gel method respectively, and the infrared spectrum (FT-IR) and Raman spectrum (Raman) , X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV), constant current charge and discharge (GCD), and electrochemical impedance spectroscopy (EIS) to measurement the structural and electrochemical properties of materials. The sol-gel method is used to prepare nickel-doped manganese dioxide. The results demonstrate that the crystal structure of MnO2 is γ-MnO2 before and after doping with Ni. When the molar ratio of Ni and Mn is 0.03:1, the particle size of sample NMO-3 is 60 nm and the specific surface area is 82 m2/g. At a scan rate of 2 mV/s, the specific capacitance of the sample reaches a maximum of 221.39 F/g, which is an increase of 54.97% over that of undoped sample. At a current density of 0.5 A/g, the specific capacitance of NMO-3 is 138.07 F/g. After 2000 charge and discharge cycles, the specific capacitance of NMO-3 remains at 75.02%。 Ni-MnO2/PANi-co-PPy composites are synthesized by in-situ polymerization method. The results show that the copolymer layer is coated on the surface of Ni-MnO2 to form core-shell structure, and the thickness of the PANi-co-PPy coating layer is 100 nm approximately. When the mass ratio of Ni-MnO2 to aniline and pyrrole mixed monomer is 1:5, the specific capacitance of the NMP-5 reaches a maximum value as high as 445.49 F/g at a scan rate of 2 mV/s, which is twice than that of Ni-MnO2. At a current density of 0.5 A/g, the specific capacitance of the NMP-5 is 385.67 F/g. After 5000 cycles, the specific capacitance of NMP-5 decreases to 61.65% of the initial value. The MnO2/PPy/SLS ternary composites are synthesized by in-situ gel method. The results demonstrate that the addition of MnO2 and SLS components cannot significantly affect the chemical structure of PPy. Without adding SLS, PPy grows on the surface of MnO2 microspheres in an orderly manner to form sea urchin structures with a diameter of about 5 μm, while after adding SLS, the morphology of the composites become nano size paticles with an average particle size of about 100 nm. When the molar ratio of Mn to pyrrole monomer is 1:5, and the mass ratio of SLS to pyrrole monomer is 10%, the specific capacitance of MPS-5-10% is 482.86 F/g at a scan rate of 2 mV/s. While at a current density of 0.2 A/g, the specific capacitance of MPS-5-10% is as high as 665.80 F/g. After 2000 cycles, the specific capacitance of MPS-5-10% reduces to 71.69% of the initial value. |
| 中图分类号： | TB333.23 |
| 开放日期： | 2020-07-24 |
谷歌
火狐
