新型燃料电池多孔电极极化特性研究

发布时间：2018-03-30 03:09

本文选题：直接乙二醇燃料电池　切入点：电极极化　出处：《哈尔滨工业大学》2017年硕士论文

【摘要】：环境污染和能源危机是两个目前人类面临的最重要的问题,解决了这两个问题可以实现人类社会的可持续发展。利用热机通过化石燃料燃烧功能方式既不环保,效率也不高。因此,近几十年来燃料电池技术由于高效绿色可持续等特点,受了广泛的关注和研究。其中,直接醇类燃料电池因其采用小分子醇类作为燃料,燃料来源广泛,储存运输方便,是燃料电池中重要的研究方向。由于醇类在燃料电池中完全氧化为二氧化碳比较困难,电子传输效率较低,但是乙二醇在燃料电池中的电子传输效率可以高达80%,是一种极具发展潜力的燃料。直接乙二醇燃料电池的输出电压由阳极电势与阴极电势共同决定,然而电池实际运行时,实际阴阳极电势都会偏离电极理论电势,导致电池性能降低。本文旨在为直接乙二醇燃料电池建立一维模型,得以探究不同运行工况对电池电极极化的影响,避免了复杂繁琐的电池组装及测试过程,对电池实际设计具有重要的参考意义。主要研究内容如下:(1)直接乙二醇燃料电池多孔电极极化模型建立在直接乙二醇燃料电池体系中,其性能受到电池温度,电催化剂及其组成以及电解质膜类型及结构等诸多因素的影响。为了能直观研究电池设计参数对性能的影响,考虑电池中物质传输、电荷传输和电化学反应三者的协同作用,利用物质运输方程、电化学动力学方程、方程的边界条件,建立起电池输出电压与电路电流密度的关系。(2)阴离子交换膜直接乙二醇燃料电池多孔电极极化模型计算分析利用建立的直接乙二醇燃料电池极化模型对燃料电池极化进行了综合分析,得到阴离子交换膜直接乙二醇燃料电池阴阳极活化极化、浓差极化和欧姆极化的曲线分布。接着分析不同物质不同浓度和电池结构参数对电池性能的影响,研究最佳的运行工况,为提高电池性能提供指导意见。(3)质子交换膜直接乙二醇燃料电池多孔电极极化模型计算分析针对最近有学者提出质子交换膜也可以在碱性条件下作为离子交换膜来传输氢氧根离子来保持电荷平衡。利用前述已完成的工作,对该类新型结构的直接乙二醇燃料电池进行模拟计算,分析不同运行工况对电池性能的影响,得到最佳的运行条件。(4)质子交换膜直接乙二醇燃料电池多孔电极极化实验研究针对已完成的质子交换膜直接乙二醇燃料电池多孔电极极化模型,采用实验研究的方法探究不同工况对电池性能的影响。主要研究阳极碱浓度和阴极氧气浓度对电池性能的影响,为实际质子交换膜直接乙二醇燃料电池的运行工况参数选择提供依据。
[Abstract]:Energy crisis and environmental pollution are the two most important currently facing humanity problems, solve these two problems can realize the sustainable development of human society. The use of heat by the burning of fossil fuels is not environmental protection function, efficiency is not high. Therefore, in recent decades the fuel cell technology due to the high efficiency of green and sustainable characteristics. Due to the extensive concern and research. Among them, the direct alcohol fuel cell because of its use of small molecular alcohols as fuel, fuel sources, convenient storage and transportation, is an important research direction of fuel cell. The complete oxidation of alcohols in the fuel cell for carbon dioxide is difficult, the efficiency of electron transfer is low, but the electronic transmission efficiency of B glycol in the fuel cell can be as high as 80%, is a promising fuel. Direct ethylene glycol by the output voltage of the fuel cell cathode and anode potential The potential is determined, but the battery in actual operation, the actual anode potential will deviate from the theory of electrode potential, resulting in lower cell performance. This paper aims to establish a one-dimensional model for direct ethylene glycol fuel cell, to explore the different effect of operation conditions on cell polarization, to avoid the battery assembly and testing process is complicated, the actual battery the design has the important reference significance. The main contents are as follows: (1) direct B porous electrode polarization model of fuel cell based on direct glycol ethylene glycol fuel cell system, its performance is influenced by the battery temperature, influence of catalysts and its composition and electrolyte membrane type and structure and other factors. In order to study the influence of design parameters directly on the performance of the battery, considering battery material transfer, the synergistic effect of charge transport and electrochemical reaction of the three, using the material transport equation, electrochemical Study of dynamics equation, the boundary conditions of the equations, establish the relationship between the output voltage of the battery and the circuit current density. (2) analysis of ethylene glycol direct fuel cell polarization model is established by using the comprehensive analysis on the fuel cell polarization anion exchange membrane direct ethylene glycol fuel cell porous electrode polarization model by anion exchange membrane direct ethylene glycol fuel cell anode activation polarization, concentration polarization and ohm polarization curve distribution. Then analyze the effect of different materials of different concentration and cell structure parameters on the performance of battery, study on the optimal operation condition, to provide guidance to improve the performance of the battery (3). Recently some scholars put forward the calculation and Analysis on the proton exchange membrane can also in alkaline under the condition of as ion exchange membrane to transfer hydroxyl ions to protect the proton exchange membrane fuel cell direct ethylene glycol porous electrode polarization model Hold the charge balance. The work has been completed, the direct fuel cell of the ethylene glycol type structure were simulated. Analysis of the influence of different operating conditions on the performance of the battery, get the best operating conditions. (4) proton exchange membrane direct study of porous electrode polarization ethylene glycol glycol direct exchange membrane fuel cell fuel cell porous electrode polarization model for proton has been completed, the paper explores the influence of different conditions on the performance of the battery. The main research is the influence of anode and cathode alkali concentration of oxygen concentration on the performance of battery, operating parameters of ethylene glycol exchange membrane direct fuel cell for the actual proton selection provides the basis.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM911.4

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