非水系锂—空气电池过渡金属氧化物正极催化剂的制备及性能研究

发布时间：2018-07-10 15:24

本文选题：锂-空气电池 + 过渡金属氧化　；参考：《东北师范大学》2014年硕士论文

【摘要】：能源是人类社会赖以生存与发展的物质基础。随着世界各国对于能源的需求愈发的强烈，化石燃料迅速消耗，，环境污染等问题日益突出，严重制约着人类社会的“和谐”发展。为了应对人类所面临的能源危机，发展新型且环境友好的新能源材料体系成为科学研究工作的热点。锂-空气电池作为一种新型的电池体系，以其极高的能量密度作为新一代储能设备，受到了科学工作者的广泛关注。在非水系锂-空气电池体系中，催化剂的活性对电池的性能发挥着至关重要的作用。与其他催化材料相比，过渡金属氧化物以其低廉的价格、高的催化活性、环境友好等优势成为潜在的锂-空气电池理想催化材料。本论文主要研究两种类型过渡金属氧化物催化剂的制备及电化学性能，其结果如下：采用水热合成-高温煅烧的方法制备MnCo2O4过渡金属氧化物，得到具有多孔结构的MnCo2O4微球。所制备的MnCo2O4微球催化剂在0.1M KOH溶液及有机电解液中表现出良好的ORR/OER反应电催化活性，其归因为构筑的多孔结构可提供更多的电化学催化活性位点。以多孔MnCo2O4微球为催化剂非水系锂-空气电池表现出良好的电化学性能，具有较低的极化， E=1.2V，卓越的放电容量，在电流密度为100mAg-1时，放电容量为5956.3mAh g-1远高于常用的Super P导电碳材料，并且具有较好的循环稳定性，可在纯氧气氛下循环50次而无衰减。采用甘氨酸-硝酸盐法制备了类钙钛矿型过渡金属氧化物La1.6Sr0.4NiO4及La1.6Sr0.4Ni0.6Cu0.4O4作为非水系锂-空气电池阴极催化材料，具有优良的电化学性能，结果表明合成的Cu元素掺杂La1.6Sr0.4Ni0.6Cu0.4O4粉体颗粒较小、分散均一，相比于La1.6Sr0.4NiO4具有更好的电化学活性，在电流密度为0.1mA cm-1时，电池的首次放电容量为5559.4mAh g-1，高于La1.6Sr0.4NiO4的4602.4mAh g-1并且具有较小的极化，充电平台大约为3.8V。同时，相比于La1.6Sr0.4NiO4，La1.6Sr0.4Ni0.6Cu0.4O4展现出良好的倍率性能及较高的循环稳定性。
[Abstract]:Energy is the material foundation for human society to survive and develop. With the increasingly strong demand for energy in the world, the rapid consumption of fossil fuels, environmental pollution and other problems have become increasingly prominent, seriously restricting the "harmonious" development of human society. In order to deal with the energy crisis, the development of new and environmentally friendly new energy materials system has become a hot spot in scientific research. As a new type of battery system, lithium-air battery is widely concerned by scientists because of its high energy density as a new generation of energy storage equipment. In non-aqueous lithium-air battery system, the activity of catalyst plays an important role in the performance of the battery. Compared with other catalytic materials, transition metal oxide (TME) has become an ideal catalyst for lithium-air batteries due to its advantages of low cost, high catalytic activity and environmental friendliness. In this paper, the preparation and electrochemical properties of two types of transition metal oxide catalysts were studied. The results are as follows: MnCo _ 2O _ 4 transition metal oxide was prepared by hydrothermal synthesis and high temperature calcination. MnCo2O4 microspheres with porous structure were obtained. The prepared MnCo _ 2O _ 4 microsphere catalyst exhibited good electrocatalytic activity in 0.1M Koh solution and organic electrolyte, which was attributed to the porous structure which could provide more electrochemical catalytic activity sites. Using porous MnCo2O4 microspheres as catalyst, the non-aqueous lithium-air battery has good electrochemical performance and has low polarization, with 1.2V, excellent discharge capacity, and when the current density is 100mAg-1. The discharge capacity of 5956.3mAh g-1 is much higher than that of conventional superp conductive carbon materials, and it has good cycling stability. It can be recirculated 50 times in pure oxygen atmosphere without attenuation. The perovskite-type transition metal oxides La1.6Sr0.4NiO4 and La1.6Sr0.4Ni0.6Cu0.4O4 were prepared by glycine-nitrate method as non-aqueous cathode materials for lithium-air batteries. The results showed that the Cu doped La1.6Sr0.4Ni0.6Cu0.4O4 powders were small. When the current density is 0.1mA cm-1, the initial discharge capacity of the battery is 5559.4mAh g-1, which is higher than that of La1.6Sr0.4NiO4 4602.4mAh g-1 and has a small polarization, and the charging platform is about 3.8V.When the dispersion is uniform, the electrochemical activity is better than that of La1.6Sr0.4NiO4. The initial discharge capacity of the battery is higher than that of La1.6Sr0.4NiO4, and the initial discharge capacity is 5559.4mAh g-1 when the current density is 0.1mA cm-1. At the same time, compared with La1.6Sr0.4Ni0.6Cu0.4O4, La1.6Sr0.4Ni0.6Cu0.4O4 shows good rate performance and high cycle stability.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.41;O643.36

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