La_(2-x)Bi_(x)CuO_(4)阴极材料的合成与电化学性质  

Synthesis and Electrochemical Properties of La_(2-x)Bi_(x)CuO_(4) Cathode Material

作　　者：庞姝彤 赵辉[1] PANG Shu-Tong;ZHAO Hui(College of Chemistry,Chemical Engineering and Materials,Heilongjiang University,Harbin 150080,China)

机构地区：[1]黑龙江大学化学化工与材料学院,哈尔滨150080

出　　处：《无机化学学报》2021年第12期2185-2192,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.51872078);黑龙江省自然科学基金(No.LH2020E105)资助。

摘　　要：采用甘氨酸-硝酸盐法合成了固体氧化物燃料电池阴极材料La_(2-x)Bi_(x)CuO_(4)(x=0、0.05、0.10),并利用X射线衍射(XRD)对材料的物相进行分析。结果表明,La_(2-x)Bi_(x)CuO_(4)形成单一的类钙钛矿结构氧化物,且晶胞体积随着铋掺杂量的增加而增大。在950℃烧结24 h过程中,La_(2-x)Bi_(x)CuO_(4)不与电解质Sm_(0.2)Ce_(0.8)O_(1.9)(SDC)发生反应,表明这种电解质材料具有良好的高温化学相容性。电导率测试结果表明Bi的掺入显著提高了材料电导率。程序升温脱附测试结果表明,铋的掺杂显著增强了材料的表面氧吸附能力。不同氧分压下的交流阻抗谱测试结果表明,La_(1.9)Bi_(0.1)CuO_(4)阴极在700℃空气中的极化电阻为0.26Ω·cm^(2),以电解质SDC支撑的单电池NiO-SDC/SDC/La_(1.90)Bi_(0.10)O_(4)在700℃的最大输出功率密度为308 mW·cm^(-2),电极反应的速控步骤为氧分子的扩散与表面吸附过程。The cathode material La_(2-x)Bi_(x)CuO_(4)(x=0,0.05,0.10)for solid oxide fuel cell was synthesized by glycine-nitrate method.The phase of the material was analyzed by X-ray diffraction(XRD)method.The results show that the material crystallizes in peroskite-type single phase oxide.Due to the increase doping amount of bismuth,the space group of the material changes from Fmmm to I4/mmm.The unit cell volume increases with the doping amount of bismuth.La_(2-x)Bi_(x)CuO_(4) cathode materials were found to show no chemical reaction with the electrolyte Sm_(0.2)Ce_(0.8)O_(1.9)(SDC)at 950℃for 24 h,indicating the good chemical compatibility of La_(2-x)Bi_(x)CuO_(4) with SDC materi-al.The bismuth doping significantly increased the electrical conductivity of the material.The highest conductivity reached 90.3 S·cm^(-1) at 350℃for La_(1.9)Bi_(0.1)CuO_(4).The temperature programmed desorption(TPD)measurement proves that bismuth doping promotes the surface oxygen absorption ability of La_(2-x)Bi_(x)CuO_(4) material,and La_(1.9)Bi_(0.1)CuO_(4) shows the largest amount of oxygen vacancies among the Bi-doped materials.The electrochemical properties of La_(2-x)Bi_(x)CuO_(4) cathode materials were further studied by AC impedance spectroscopy under different oxygen partial pressures.The polarization resistance of La_(1.9)Bi_(0.1)CuO_(4) was 0.26Ω·cm^(2) at 700℃in air.The peak power density(PPD)at 700℃was 308 mW·cm^(-2) for the SDC electrolyte supported single cell NiO-SDC/SDC/La_(1.90)Bi_(0.10)O_(4).The reaction rate limiting step is identified to be a mixed step involving the gas oxygen diffusion through the porous cathode and the surface adsorption process.

关 键 词：固体氧化物燃料电池 La_(2-x)Bi_(x)CuO_(4)电极材料 电极反应 

分 类 号：O614.81[理学—无机化学]