【作者】 张超；

【导师】 马贵平； 吴刚强；

【作者基本信息】 北京化工大学 ， 材料工程（专业学位）， 2021， 硕士

【摘要】 随着世界工业化的快速发展,不可再生资源的消耗产生的能源危机和环境污染等问题日益严重,研究绿色能源转换装置尤为重要。空气电池因具有绿色环保、比容量高、成本低和安全性高等优点而受到广泛的关注和研究。但是制约其商业发展的主要原因是阴极发生的氧还原反应(Oxygen Reduction Reaction),目前主要以Pt/C为主的贵金属催化剂制备成本高,限制了其广泛应用。因此为推动催化剂的发展,开发成本低活性高的非贵金属碳基阴极电催化剂具有重要意义。本文选取二维材料MXene作为导电基材,通过原位生长引入氮源、碳源,形成基于MXene碳纳米管包裹金属纳米颗粒三维阵列结构,研究其电催化性能并提出催化机理,测试催化剂在液/固锌空气电池中的实际应用。通过盐酸加氟化锂原位生成氢氟酸的方法制备MXene,在聚乙烯亚胺作用下经过定向冷冻干燥的过程形成三维导电网络,过渡金属Fe、Co均匀锚定在导电网络中,经三聚氰胺辅助碳化形成Fe-Co/CNT@MXene三维阵列,多个活性位点Fe-N-C、Co-N-C和吡啶氮协同作用,通过VASP构造模型、DFT计算反应自由能,确定反应机理。并且研究不同温度和金属对催化性能的影响,分析Fe-Co/CNT@MXene-T的LSV曲线,其中Fe-Co/CNT@MXene-8具有0.85 V的半波电位,较商用Pt/C的半波电位0.83V具有更优异的催化性能,并得到所制备的催化剂具有良好的稳定性能和耐甲醇性能,在经过30000秒测试中较Pt/C仅仅衰减9.8%,同时制备的催化剂有较好的OER性能并组装的液态锌空气电池具有开路电压1.5 V,比容量754 mAh g-1 Zn和能量密度138 mW cm-2,并能表现出长达375 h的充放电循环稳定性能。进一步研究催化剂在固态柔性锌空气电池的性能,用聚丙烯酰胺(PAM)作为固态电解质制备出三明治固态柔性电池,具有开路电压1.42 V,能量密度16 mW cm-2,串联的电池能点亮LED灯,并具有22 h的长期循环稳定性,为柔性器件供能提供很好的应用前景。更多还原

【Abstract】 With the rapid development of the world’s industrialization,the energy crisis and environmental pollution caused by the consumption of non-renewable resources have become more and more serious.Research on green energy conversion devices is particularly important.Air batteries have received extensive attention and research due to their advantages of environmental protection,high specific capacity,low cost and high safety.However,the main reason restricting its commercial development is the Oxygen Reduction Reaction at the cathode.At present,the high preparation cost of precious metal catalysts mainly based on Pt/C limits its wide application.Therefore,in order to promote the development of catalysts,it is of great significance to develop non-noble metal carbon-based cathode electrocatalysts with low cost and high activity.In this paper,the two-dimensional material MXene is selected as the conductive substrate,and the nitrogen source and carbon source are introduced through in-situ growth to form a three-dimensional array structure based on MXene carbon nanotubes wrapped with metal nanoparticles.The electrocatalytic performance is studied and the catalytic mechanism is proposed.The catalyst is tested in liquid./Practical application of solid zinc-air battery.MXene is prepared by the method of hydrochloric acid and lithium fluoride to generate hydrofluoric acid in situ.Under the action of polyethyleneimine,a three-dimensional conductive network is formed through a directional freezedrying process.The transition metals Fe and Co are uniformly anchored in the conductive network.Auxiliary carbonization to form Fe-Co/CNT@MXene three-dimensional array,multiple active sites Fe-NC,Co-NC and pyridine nitrogen synergistically,through the VASP structure model,DFT to calculate the free energy of reaction to determine the reaction mechanism.And to study the effect of different temperatures and metals on the catalytic performance,and analyze the LSV curve of F e-Co/CNT@MXene-T,where FeCo/CNT@MXene-8 has a half-wave potential of 0.85 V,which is better than commercial Pt/C The half-wave potential of 0.83 V has more excellent catalytic performance,and the prepared catalyst has good stability and methanol resistance.In the 30,000 second test,the attenuation is only 9.8%compared with Pt/C.At the same time,the prepared catalyst has better performance.The assembled liquid zinc-air battery has an open circuit voltage of 1.5V,a specific capacity of 754 mAh g-1 Zn and an energy density of 138 mW cm ’2,and can exhibit a charge-discharge cycle stability of 375 h.To further study the performance of the catalyst in the solid-state flexible zinc-air battery,use polyacrylamide(PAM)as the solid electrolyte to prepare a sandwich solid-state flexible battery with an open circuit voltage of 1.42 V and an energy density of 16mW cm ’2.The battery in series can light up the LED light.And has a longterm cycle stability of 22 h,which provides a good application prospect for the energy supply of flexible devices.更多还原