论文总字数：28597字

摘 要

相对于传统氧离子导体燃料电池(SOFC-O^2-)通常在高于800 °C的条件下工作，质子导体燃料电池(SOFC- H )可以在650 °C以下中低温条件工作，且产生的高功率密度使得固体氧化物燃料电池的商业应用成为可能。在极化条件下，三相界面(TPB)区形成了大量的水，可能会阻碍后续反应的速率。然而，通过进一步引入质子传导到电极（即当使用三相导体材料作为阴极可以进行氧离子、电子和质子的输运）。由于质子可以通过阴极体扩散到达整个阴极表面，因此在暴露于空气中的阴极的整个表面都会形成水。如果材料具有一定的储水能力，甚至会在阴极体内部形成水，因此，三相导体材料非常适合于做SOFC-H 和双离子燃料电池的阴极。

本论文选择Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF-1)这种氧化还原活性高的钙钛矿材料作为阴极材料，并通过调整化学计量比合成两种新的阴极材料，即(Ba_0.5Sr_0.5)_1.5(Co_0.8Fe_0.2)O_3-δ (BSCF-1.5)和(Ba_0.5Sr_0.5)₂(Co_0.8Fe_0.2)O_3-δ (BSCF-2)。对三种材料的对称电池进行电化学阻抗测试，我们发现以BSCF-1.5为阴极的对称电池阻抗最低。600 °C时，BSCF-1、BSCF-1.5和BSCF-2的阻抗分别为0.965、0.538和1.274 Ω cm²。因此，本研究选择BSCF-1.5作为单电池的阴极材料。以BSCF-1.5为阴极的单电池在650、600、550、500 °C下的功率密度峰值分别为1455、1055、745、523 mW cm^-2，这表明BSCF-1.5是一种具有高输出功率的阴极材料。

关键词：质子导体 燃料电池 阴极 三相导体材料 (Ba_0.5Sr_0.5)_1.5Co_0.8Fe_0.2O_3-δ

Application of high performance cathode material (Ba_0.5Sr_0.5)_xCo_0.8Fe_0.2O_3-δ(x=1, 1.5, 2) in SOFC- H

Abstract

Compared with the traditional oxygen ion conductor fuel cell (SOFC-O^2-) which usually works at the temperature higher than 800 °C, the proton conductor fuel cell (SOFC- H ) can work at the temperature lower than 650 °C, and the high power density produced makes the commercial application of SOFC possible. Under the condition of polarization, a large amount of water is formed in the TPB region, which may hinder the subsequent reaction rate. However, by further introducing protons to the electrode (that is using three-phase conductor material as a cathode to transport oxygen ions, electrons and protons), since protons can diffuse through the cathode body to the whole cathode surface, water will form on the whole surface of the cathode exposed to air. If the material has a certain water storage capacity, even water will form inside the cathode body, so a three-phase conductor material is very suitable for SOFC- H and double ion fuel cells.

In this paper, BSCF-1, a perovskite material which has been found for a long time, is selected as the cathode material, and two new cathode materials, BSCF-1.5 and BSCF-2 are produced by adjusting the stoichiometric ratio. The electrochemical impedance of three kinds of symmetrical batteries was measured. The results show that BSCF-1.5 cathode has the lowest impedance. At 600 °C, the impedances of BSCF-1, BSCF-1.5 and BSCF-2 are 0.965, 0.538 and 1.274 Ω cm^-2, respectively. Therefore, BSCF-1.5 was selected as the cathode material of single cell in this study. The power density peaks of BSCF-1.5 single cell at 650, 600, 550 and 500 °C are 1455, 1055, 745 and 523 mW cm^-2 respectively, which shows that BSCF-1.5 is a promising cathode material.

Keywords: proton conductor; fuel cell; cathode; three-phase conductor material; (Ba_0.5Sr_0.5)_1.5Co_0.8Fe_0.2O_3-δ

目录

摘要 Ⅰ

Abstract Ⅱ

第一章 绪论 1

1.1 前言 1

1.2 固体氧化物燃料电池概述 2

1.2.1 固体氧化物燃料电池类型及其工作原理 2

1.2.2 质子导体燃料电池的关键材料 4

1.2 本论文的研究目的和实验内容 9

1.2.1 本实验的研究目的 9

1.2.2 本论文的工作内容 9

第二章 实验部分 11

2.1 实验试剂和仪器 11

2.2 电解质粉体以及阴极粉体、浆料的制备 12

2.2.1 溶胶凝胶法制备电解质和阴极粉体 12

2.2.2 阴极浆料的制备 13

2.3 电池的制备 13

2.3.1 对称电池的制备 13

2.3.2 单电池的制备 14

2.4 表征方法 15

2.4.1 X射线衍射(XRD) 15

2.4.2 扫描电子显微镜(SEM) 15

2.5 电化学性能测试 15

2.5.1 电化学阻抗谱(EIS) 15

2.5.2 单电池性能 16

第三章 结果与讨论 18

3.1 XRD表征 18

3.1.1 (Ba_0.5Sr_0.5)_xCo_0.8Fe_0.2O_3-δ (BSCF-x, x=1, 1.5, 2)阴极粉体表征 18

3.1.2 BSCF-1.5与BZCYYb粉体表征 19

3.2 SEM表征 19

3.3 电化学阻抗谱 21

3.4 单电池性能测试 23

第四章 结论与展望 25

4.1 结论 25

4.2 展望 25

参考文献 26

致谢 31

绪论

前言

随着社会发展，人类对能源的需求越来越大。传统能源如石油、煤炭由于储量有限且使用过程中容易产生污染物，对环境造成巨大破坏，如酸雨，温室效应，平流层臭氧消耗。这些传统的能源技术制约着环境友好型社会经济的发展，因此寻找更加安全、环保、高效的能源显得格外重要^[1]。相对于传统的消耗石油等不可再生资源的能源装置，燃料电池拥有着诸多特点，发电效率高，避免产生了温室气体，对环境也更友好，因此吸引了全世界的关注^[2]。

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