碱性膜燃料电池电极设计对性能和传输过程影响的研究

发布时间：2018-06-23 22:23

本文选题：碱性阴离子交膜燃料电池 + 电解质含量　；参考：《天津大学》2016年硕士论文

【摘要】：随着能源和环境问题日益严峻,节能减排的要求逐渐提升。以内燃机为主要动力源的车辆,作为主要的能耗和排放来源,是节能减排的重要领域。因此,相对低能耗、低排放和高效率的电动车(Electric vehicle,EV)和燃料电池车(Fuel cell vehicle,FCV)逐渐受到越来越多的关注。但是基于中国国情,考虑到电能的来源和H2的制备方法,内燃机车(Internal combustion engine,ICEV)、EV和FCV的优劣尚未可知,因此本研究首先基于中国国情、通过生命周期分析,比较了ICEV、EV和FCV在能耗、碳排放和总体效率等方面优劣。结果表明,通过天然气重整与核电电解水制备H2的燃料电池车在上述三个方面都是可行的。在车用燃料电池中,碱性阴离子交换膜燃料电池(Alkaline anion exchange membrane fuel cell,AAEMFC)是具有竞争力的选择之一。和质子交换膜燃料电池(Proton exchange membrane fuel cell,PEMFC)相比,AAEMFC具有较好的电化学动力学特性和较低的贵金属催化剂依赖性,因而被广泛关注。在AAMEFC的结构中,电极设计对其性能有着重要的影响,如电解质含量、有无微孔层(Micro porous layer,MPL)。相关的实验研究相对缺乏。因此,本研究制备了不同电解质含量的AAEMFC,总结出不同电解质含量对燃料电池性能的影响;引入MPL、提高阳极背压和相对湿度的影响也通过实验加以总结。结果表明,电解质含量越高,燃料电池性能越好,耐久性越长;引入微孔层、提高阳极背压也会改善燃料电池的性能。最后,本文建立了AAEMFC的三维多相流非恒温数值模型,深入电池内部,从水管理的角度解释引入MPL、提高阳极背压和削减膜厚度对于液态水传输和电池性能的影响。结果表明,引入阳极MPL、提高阳极背压和削减膜厚度,会改善电池性能,且增幅与电流密度成正比,而引入阴极MPL对电池性能影响较小,因为阴极处于缺水状态,MPL无法发挥作用。随着阳极背压的提高和AAEM厚度的削减,AAEM中水传输的主导机制发生变化:由扩散为主变成扩散和渗透并重。此外,在相邻的多孔层界面,可以观测到液态水阶跃现象。
[Abstract]:With the increasingly serious energy and environmental problems, the requirements of energy conservation and emission reduction are gradually raised. As the main energy consumption and emission source, the vehicle with internal combustion engine as the main power source is an important field of energy saving and emission reduction. Therefore, relatively low energy consumption, low emission and high efficiency electric vehicle (EV) and fuel cell vehicle (FCV) have attracted more and more attention. However, considering the source of electric energy and the preparation method of H2, the advantages and disadvantages of EV and FCV for internal combustion engineering are not known. Therefore, based on the situation of China, the energy consumption of EV and FCV is compared by life cycle analysis. Carbon emissions and overall efficiency and other advantages and disadvantages. The results show that it is feasible to prepare H2 fuel cell vehicle by natural gas reforming and electrolytic water. Basic anion exchange membrane fuel cell (Alkaline anion exchange membrane fuel) is one of the competitive choices in vehicle fuel cells. Compared with proton exchange membrane fuel cell (PEMFC), AAEMFC has better electrochemical kinetic properties and lower dependence on noble metal catalyst, so it has been paid more attention to. In the structure of AAMEFC, electrode design plays an important role in its performance, such as electrolyte content and micro porous layer. There is a relative lack of experimental research. In this study, AAEMFC with different electrolyte content was prepared, and the effects of different electrolyte content on fuel cell performance were summarized, and the effects of MPLs on anode back pressure and relative humidity were also summarized by experiments. The results show that the higher the electrolyte content, the better the performance and durability of the fuel cell, and the better the performance of the fuel cell is when the microporous layer is introduced and the anode back pressure is increased. Finally, a three-dimensional multiphase flow non-constant temperature numerical model of AAEMFC is established, and the effect of MPLs on the liquid water transport and battery performance is explained from the point of view of water management by increasing the back pressure of the anode and reducing the thickness of the film. The results show that the performance of the cell can be improved by adding anode MPLs, increasing the anode back voltage and reducing the film thickness, and the increase is proportional to the current density. However, the introduction of cathode MPL has little effect on the performance of the battery, because the cathode is in the condition of water shortage and MPL can not play its role. With the increase of anode back pressure and the reduction of AAEM thickness, the dominant mechanism of water transport in AAEM is changed: from diffusion to diffusion and permeation. In addition, the liquid water step phenomenon can be observed at the interface of the adjacent porous layer.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM911.4

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