论文总字数：26861字

摘 要

阴极材料是中温固体氧化物燃料电池(IT-SOFC)的核心。而不同的制备方法对于阴极材料的性能有着不小的影响。为了获得更高性能的阴极材料，势必要研究不同制备方法的优劣。本文分别用固相反应法、甘氨酸硝酸盐法(GNP法)和柠檬酸硝酸盐自燃烧法制备La₂NiO_{4 δ}粉料，并测试了它们的性能。

从各粉料的XRD图谱来看，固相反应法在1200℃下煅烧18小时可以达到理想的制备效果，图谱中没有杂相。GNP法在900℃下煅烧2小时可以达到预期的制备效果。柠檬酸硝酸盐自燃烧法在700℃和900℃下都没有达到良好的制备效果。

根据三种粉料烧结体的相对密度数据，固相法制备的La₂NiO_{4 δ}粉体的相对密度在煅烧48小时后达到最大值：95%。GNP法制备的样品在1350℃时有最大相对密度：97.3%，且在1400℃时出现了过烧。柠檬酸硝酸盐自燃烧法制备的样品在1400℃时有最大值98.6%。

根据三种粉料的电性能数据，三种样品的电导率都随着温度的升高呈现出先增加后降低的趋势。固相反应法、GNP法和柠檬酸硝酸盐自燃烧法制备的样品的电导率最大值分别为20.3S·cm^-1、70.5 S·cm^-1和24.1S·cm^-1。

由三种粉体的热膨胀曲线可以看出，随着温度升高，三种粉料的热膨胀都呈现出接近线性增加的趋势。由固相反应法、GNP法和柠檬酸硝酸盐自燃烧法制备的样品的热膨胀率分别为14.08×10^-6K^-1、14.42×10^-6K^-1和13.84×10^-6K^-1。

研究了GNP法制备的样品电化学性能，发现1050℃煅烧的电极极化电阻最小，为0.44 Ω·cm²，可以认为以LN为阴极材料、SDC为电解质材料制备的对电池的最优制备温度为1050℃。

关键词：阴极材料 固相反应法 甘氨酸硝酸盐法 柠檬酸硝酸盐自燃烧法

Abstract

Cathode material is the key to intermediate temperature solid oxide fuel cell (IT-SOFC). Different preparation methods have a great influence on the properties of cathode materials. In order to obtain cathode materials with higher performance, it is necessary to study the advantages and disadvantages of different preparation methods. In this paper, La₂NiO_{4 δ} powders were prepared by solid-phase reaction, glycine-nitrate process (GNP) and citric acid-nitrate self-combustion, and their properties have been tested.

According to the XRD spectra of each powder, the solid phase reaction can achieve ideal preparation effect by calcining at 1200℃ for 18 hours, and there is no impurity in the spectrum. GNP method can achieve the desired preparation effect at 900℃ for 2 hours. The citric acid nitrate self combustion method did not achieve good preparation effect at 700℃ or 900℃.

Based on the relative density data of three kinds of powder sinter, The relative density of La₂NiO_{4 δ} delta powders prepared by solid phase reaction method reached 95% after 48 hours. The maximum relative density of the sample prepared by GNP method is 97.3% at 1350℃, and there has been over burning at 1400℃. The maximum value of the sample prepared by citric acid-nitrate self-combustion at 1400℃was 98.6%.

According to the data of the electrical properties of three kinds of powder, the conductivity of the three samples showed a trend of increasing first and then decreasing with the increase of temperature.The maximum values of the conductivities of the samples prepared by solid phase reaction method, GNP method and citric acid nitrate combustion were 20.3 S·cm^-1, 70.5 S·cm^-1 and 24.1 S·cm^-1.

According to the thermal expansion curves of the three powders, with the increase of temperature, the thermal expansion of the three powders showed a trend of almost linear increase. Thermal expansion ratioes of the samples prepared by solid phase reaction method, GNP method and citric acid nitrate combustion were 14.08×10^-6K^-1、14.42×10^-6K^-1 and 13.84×10^-6K^-1。

The electrochemical properties of samples prepared by GNP method has been investigated and found the electrode resistance of the electrode calcined at 1050℃ has the minimum value: 0.44 Ω·cm². It can be considered that the optimum preparation temperature of the symmetrical cell prepared with LN cathode material and SDC electrolyte material is 1050℃.

Key Words: Cathode material; Solid-phase reaction; Glycine-nitrate process; Citric acid-nitrate self-combustion

目录

摘 要 I

Abstract i

第一章 文献综述 1

1.1 概述 1

1.2 SOFC的组成 2

1.3 SOFC的工作原理 3

1.4 SOFC阴极的反应机理 4

1.5 类钙钛矿(A₂BO₄)型阴极材料 5

1.5.1 类钙钛矿A₂BO₄型阴极材料 5

1.5.2 复合阴极材料中A₂BO₄的复合 7

1.6 本论文的研究内容、目的及意义 7

第二章 材料的合成制备与表征 8

2.1 原料及仪器 8

2.1.1 原料 8

2.1.2 仪器 9

2.2 样品合成与制备 9

2.2.1 固相反应法 9

2.2.2甘氨酸硝酸盐法(GNP法) 10

2.2.3 柠檬酸硝酸盐自燃烧法 11

2.2.4阴极条的制备 13

2.2.5 对电池的制备 13

2.3．表征方法与性能测试 13

2.3.1 X射线衍射(XRD)分析 13

2.3.2 样品的烧结性能测试 14

2.3.3 电性能测试 14

2.3.4 热膨胀性能测试 16

2.3.5 电化学性能测试 16

第三章 不同方法制备的La₂NiO_{4 δ}的性能比较 18

3.1 La₂NiO_{4 δ}粉体的XRD分析 18

3.2 La₂NiO_{4 δ}粉体的烧结性能 19

3.3 La₂NiO_{4 δ}粉体的电性能 20

3.4 La₂NiO_{4 δ}粉体的热膨胀性能 21

3.5 电化学性能 23

第四章 结论与展望 24

4.1 结论 24

4.2 展望 24

参考文献 26

第一章 文献综述

1.1 概述

能源是经济社会运行的支柱，是人类前进的引擎。而随着人类文明的规模不断扩展，需要越来越多的能源作为支撑，但是当下全世界使用的大部分仍然是化石能源。然而，化石能源储量有限，而且伴随着严重的环境问题：过量的碳排放造成气候变暖、燃烧产物造成大气污染等。在无法短时间内取代化石能源的情况下，提高化石能源的利用率并减少污染成了当务之急。燃料电池可以越过燃烧阶段，直接完成化学能到电能的转化，中间环节少，能量转化效率高^[1-5]。所以燃料电池被认为是21世纪最有希望的能源技术之一 ^[6]。各种燃料电池的特点，如表1-1所示。

表1-1 各种燃料电池的特点^[7,8]

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