锂空气电池多孔负极结构及双功能正极催化材料电化学性能分析

发布时间：2018-01-11 17:06

本文关键词：锂空气电池多孔负极结构及双功能正极催化材料电化学性能分析　出处：《渤海大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着环境污染日益严重,不可再生能源短缺日益加剧,开发一种新型环保的可持续能源势在必行。锂空气电池由于具有高的理论比能量在全世界受到广泛的关注。但是,在锂空气电池实现商业化的道路上还存在下列问题:电解液溶剂易挥发、电解液充电时易分解、锂金属负极易腐蚀、锂枝晶的生长、正极空隙堵塞等。这些问题是目前锂空气电池研究的热点,其中如何对锂阳极进行有效的保护,如何提高阴极催化剂的催化性能是改善锂空气电池性能的关键。本文提出了一种双气体通道多孔阳极结构的锂空气电池,能在电池内部形成一个动态的气相平衡,有效抑制了氧气向阳极的渗透,从而保护了锂阳极。通过对放电结束后阳极片的电子扫描显微镜和拉曼光谱分析,确定阳极腐蚀受到抑制。通过循环伏安,交流阻抗,恒流充放电及功率能量特性分析,这种新型的锂空气电池均具有良好表现,首次放电容量能达到2910 mAh g~(-1),比能量达到7200 Wh kg~(-1),循环寿命能达到38次。本文还对锂空气电池阴极催化剂进行了研究。用真空直流电弧法制备了一种纳米催化材料Mn_3O_4/MnO。使用XRD、SEM、BET等手段对这种新型材料进行了表征,结果显示这种材料具有晶格缺陷和空位,大大提高了材料的电子电导率和催化活性,且颗粒尺寸与孔径大小都适用于锂空气电池。将其制成电极组装成锂空气电池,通过循环伏安、交流阻抗、恒流充放电等方法对其催化性能进行了测试分析,发现这种催化剂在氧氧化和氧还原中均有很好的表现,能大幅提高电池的循环寿命,在0.100 mA cm-2电流密度1000 mAh g~(-1)容量限制下可以稳定工作29个循环。
[Abstract]:With the increasingly serious environmental pollution, the shortage of non-renewable energy is becoming more and more serious. It is imperative to develop a new kind of sustainable energy for environmental protection. Lithium air batteries have attracted wide attention all over the world because of their high theoretical specific energy. The following problems still exist in the commercialization of lithium-air batteries: the solvent of electrolyte is volatile, the electrolyte is easy to decompose when charging, the negative electrode of lithium metal is easy to corrode, and the growth of lithium dendrite. These problems are the focus of lithium air battery research, and how to protect the lithium anode effectively. How to improve the catalytic performance of cathode catalyst is the key to improve the performance of lithium-air battery. It can form a dynamic gas equilibrium in the battery, effectively inhibit the oxygen permeation to the anode, thus protecting the lithium anode. The anode is analyzed by scanning electron microscope and Raman spectroscopy after the discharge. It is determined that the anode corrosion is restrained. Through the analysis of cyclic voltammetry, AC impedance, constant current charge and discharge and power energy characteristics, this new type of lithium-air battery has good performance. The initial discharge capacity can reach 2910 mAh / g ~ (-1) and the specific energy reaches 7200 Wh / kg ~ (-1). The cycle life can reach 38 times. The cathode catalyst for lithium-air battery was studied in this paper. A nanometer catalytic material MnTi3O4 / MNO was prepared by vacuum DC arc method. XRD was used. The new material was characterized by means of SEMP-BET. The results show that the material has lattice defects and vacancies, which greatly improves the electronic conductivity and catalytic activity of the material. The particle size and pore size are suitable for lithium-air battery. The electrode is made into a lithium air battery, and its catalytic performance is tested by cyclic voltammetry, AC impedance, constant current charge and discharge and so on. It is found that the catalyst has a good performance in oxygen oxidation and oxygen reduction, and can greatly improve the cycle life of the battery. Under the limit of 0.100mA cm-2 current density 1000 mAh / g ~ (-1), 29 cycles can be stably operated.
【学位授予单位】：渤海大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TM911.41

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