摘要
开发具有优异电化学活性的阴极材料对中温固体氧化物燃料电池(IT-SOFC)的应用至关重要。采用固相法制备无钴阴极材料Bi_(1-x)Ca_(x)FeO_(3-δ)(BCFx,x=0.1、0.2和0.3),通过该体系材料的物相结构、电导率、氧传输特性以及电化学性能研究表明,950℃时可以合成具有单相钙钛矿结构的Bi_(1-x)Ca_(x)FeO_(3-δ)(x=0.1、0.2和0.3)阴极粉体。BCFx阴极材料中,样品BCF0.2具有较高的电化学催化活性,750℃时,对称电池极化阻抗为0.06Ω·cm^(2),Ni-(Y_(2)O_(3))_(0.08)(Zr O_(2))_(0.92)(Ni-8YSZ)(Ni-8YSZ)阳极支撑单电池最大功率密度为730 mW/cm^(2)。由电导弛豫结果得知,BCF0.2阴极良好的氧还原催化活性主要归因于其较高的氧扩散系数和表面交换系数。氧还原反应动力学研究表明,样品BCF0.2阴极氧还原反应的速率控制步骤为吸附氧的解离过程。
Developing cathode materials with superior electrochemical activity is of great importance to the application of intermediate-temperature solid oxide fuel cell(IT-SOFC).In this paper,Bi_(1-x)Ca_(x)FeO_(3-δ)(BCFx,x=0.1,0.2 and 0.3)compounds were synthesized via solid-state reaction as a cathode material for IT-SOFC.The phase structure,electrical conductivity,oxygen transport performance,and the electrochemical performances of these compounds were evaluated.The as-prepared BCFx compounds show a single-phase perovskite structure.Among the BCFx materials,Bi_(1-x)Ca_(x)FeO_(3-δ)(BCF0.2)oxide has the maximum electrochemical catalytic activity.The polarization resistance of BCF0.2 cathode on symmetrical cell is 0.06Ω/cm^(2)at 750℃in air.Meanwhile,the maximum peak power density of Ni-(Y_(2)O_(3))_(0.08)(Zr O_(2))_(0.92)(Ni-8YSZ)anode-supported single cell reaches 730 m W/cm^(2)at 750℃.As is indicated by the electrical conductivity relaxation,the favorable oxygen reduction reaction catalytic activity of BCF0.2 can be ascribed to the higher oxygen bulk diffusion and surface exchange coefficient.The results of oxygen reduction kinetics reveal that the dissociation of adsorbed molecular oxygen is a limiting step for oxygen reduction reaction on BCF0.2 cathode.
作者
冯伟伟
赵慧粉
沈睦夷
陈涵
郭露村
FENG Weiwei;ZHAO Huifen;SHEN Muyi;CHEN Han;GUO Lucun(Nanjing Tech University,College of Materials Science and Engineering,Nanjing,211816,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2022年第5期1248-1256,共9页
Journal of The Chinese Ceramic Society
基金
江苏高校优势学科建设工程资助项目(PAPD)。
关键词
固体氧化物燃料电池
阴极
电导弛豫
电化学性能
solid oxide fuel cell
cathode
electrical conductivity relaxation
electrochemical performance
