摘要
利用溶胶凝胶法合成了La_(1.5)Sr_(0.5)NiO_(4+δ)掺杂Co的阴极材料La_(1.5)Sr_(0.5)Ni_(1−x)CoxO_(4+δ)(x=0、0.2、0.4、0.6)。通过X射线衍射、X射线光电子能谱、热重、热膨胀系数的测定和扫描电镜等技术探究了材料的相结构、元素组成、热力学性能和表面形貌。结果表明,所合成的样品为具有类钙钛矿型结构的单一纯相,掺杂Co元素使材料的热膨胀系数有所提高。将该材料应用于固体氧化物燃料电池(SOFC)阴极,进行了电导率及电化学阻抗谱的测定。结果发现,La_(1.5)Sr_(0.5)Ni_(1−x)CoxO_(4+δ)的电导率随着Co元素掺杂量的提高而升高,当x=0.4时La_(1.5)Sr_(0.5)Ni_(0.6)Co_(0.4)O_(4+δ)的电导率最高,达51.21 S/cm(800℃);当x值大于0.4时,其电导率明显下降。此外,La_(1.5)Sr_(0.5)Ni_(0.6)Co_(0.4)O_(4+δ)在电化学阻抗谱测试中也呈现出了最低的极化电阻(4.180Ω·cm^(2),700℃),表现出较好的电化学性能。
A series of Co-doped La_(1.5)Sr_(0.5)Ni_(1−x)CoxO_(4+δ)cathode materials(x=0,0.2,0.4 and 0.6)were synthesized by sol-gel method and characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA),coefficient of thermal expansion(CTE)measurement and scanning electron microscope(SEM).The results suggest that all La_(1.5)Sr_(0.5)Ni_(1−x)CoxO_(4+δ)samples have a single pure phase with the perovskite-like structure and the doping with the Co element can increase the CTE value.Using La_(1.5)Sr_(0.5)Ni_(1−x)CoxO_(4+δ)as the cathode materials in the solid oxide fuel cell(SOFC),their electrical conductivity and electrochemical impedance spectroscopy were measured.The results indicate that the conductivity increases with the increase of Co doping amount and the La1.5Sr0.5Ni0.6Co0.4O4+δsample with x=0.4 displays the highest conductivity of 51.21 S/cm at 800℃;however,a higher content of Co(x>0.4)leads to a decrease of the conductivity.In addition,La1.5Sr0.5N0.6Co0.4O4+δexhibits the lowest polarization resistance of 4.180Ω·cm2 in electrochemical impedance spectrum at 700℃,displaying its excellent electrochemical properties as the cathode materials.
作者
李宁
李松波
安胜利
杜旭
薛良美
倪洋
LI Ning;LI Song-bo;AN Sheng-li;DU Xu;XUE Liang-mei;NI Yang(School of Chemistry and Chemical Engineering,Inner Mongolia University of Science&Technology,Inner Mongolia Baotou 014010,China;School of Metallurgical and Material Engineering,Inner Mongolia University of Science&Technology,Inner Mongolia Baotou 014010,China)
出处
《燃料化学学报（中英文）》
EI
CAS
CSCD
北大核心
2023年第4期511-518,共8页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(51974167)
内蒙古自治区高等学校科学研究项目(NJZZ22449)资助。
关键词
固体氧化物燃料电池
类钙钛矿
阴极材料
solid oxide fuel cell
perovskite-like structure
cathode material
