耐铬腐蚀的固体氧化物燃料电池阴极材料的结构设计及性能优化

Structural design and performance optimization of chromium-resistant solid oxide fuel cell cathode materials

通过甘氨酸-EDTA-硝酸盐燃烧法(GNP)制备了La_(2)NiO_(4)-δ、La_(2)Ni_(0.9)Fe_(0.1)O_(4)-δ、La_(2)Ni_(0.8)Fe_(0.2)O_(4)-δ、La_(2)Ni_(0.6)Fe_(0.4)O_(4)-δ这4种阴极材料,分析其结构;测试阴极粉体与电解质粉体的化学相容性;测试阴极材料的抗铬中毒性能;采用直流四端子方法测定其电导率;测试热膨胀系数;最后测试了对称电池的极化电阻。通过对材料进行的上述研究和测试,对不同阴极材料的固体氧化物燃料电池的性能有了初步了解。结果表明:La_(2)NiO_(4)-δ为纯相,在La_(2)NiO_(4)-δ基础上掺杂Fe元素,当掺杂的Fe元素量逐渐增加,粉体结构逐渐改变,通过分析发现了新相四氧化三铁。4种阴极粉体与电解质都具有良好的化学相容性。随着Fe元素掺杂量的增加,抗铬中毒性能更加优越,电导率逐渐变低,极化阻抗增高。以期对以后固体氧化物燃料电池性能的研究创造更为便利的条件。

Four kinds of cathode materials including La_(2)NiO_(4)-δ,La_(2)Ni_(0.9)Fe_(0.1) O_(4)-δ,La_(2)Ni_(0.8)Fe_(0.2)O_(4)-δand La_(2)Ni_(0.6)Fe_(0.4)O_(4)-δwere prepared.The XRD patterns, the chemical compatibility of the cathode powder with the electrolyte powder and the anti-chromium poisoning properties of the cathode materials were investigated.The conductivity was measured by DC four terminal method.Furthermore, the coefficient of thermal expansion and the polarization resistance of the symmetrical cell were tested.Through the above research and testing of materials, the performances of solid oxide fuel cells with different cathode materials were preliminarily understood.The results showed that La_(2)NiO_(4)-δwas pure phase.For the La_(2)NiO_(4)-δdoped Fe element, when the amount of doped Fe element slowly increased, the powder structure gradually changed and formed a new phase of iron oxide.Four kinds of cathode powders and electrolytes had good chemical compatibility.With the increase in the amount of doped Fe elements, anti-chrome poisoning performance was far superior, the conductivity was gradually lower and the polarization resistance increased.Based on the above conclusions, it was expected to create more convenient conditions for the future research of solid oxide fuel cell performance.