梯度复合阴极LaBaCo_2O_(5+δ)-Ce_(0.8)Sm_(0.2)O_(1.9)的制备及电化学性能  

Preparation and electrochemical performances of LaBaCo_2O_(5+δ)-Ce_(0.8)Sm_(0.2)O_(1.9) graded composite cathode

作　　者：李瑞锋[1] 陈涵[1] 郭露村[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2012年第2期1-5,共5页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省科技支撑计划资助项目(BE2009169);江苏高校优势学科建设工程资助项目

摘　　要：采用机械混合法制备中温固体氧化物燃料电池梯度复合阴极材料LaBaCo2O5+δ-Ce0.8Sm0.2O1.9(LBCO-SDC)。通过X线衍射(XRD)分析、扫描电镜(SEM)分析、热膨胀法、交流阻抗谱法和循环伏安法分别对晶体结构、界面微观结构、热膨胀性及电化学性能进行表征。结果表明:LBCO阴极与SDC电解质之间具有良好的化学相容性;电解质SDC的添加有效地降低了阴极材料LBCO的热膨胀系数;双层梯度复合阴极比单层阴极表现出更小的比表面电阻以及极化过电位,显示出更好的电化学性能;在700℃时,双层梯度复合阴极的比表面电阻与LBCO阴极相比下降了约13.2%,极化过电位(电流密度为0.20 A/cm2)从51.0 mV下降到46.4 mV。The LaBaCo2O5＋δ-Ce0.8Sm0.2O1.9（LBCO-SDC） graded composite cathode for intermediate temperature solid oxide fuel cells was prepared by a mechanical mixing method.The crystal structure,interfacial microstructure,thermal expansion,and electrochemical performances were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,dilatometry,AC impedance,and cyclic voltammetry techniques.Results showed that the LBCO cathode had good chemical compatibility with the SDC electrolyte.The addition of SDC electrolyte to LBCO cathode could effectively reduce its thermal expansion coefficient.The double-layer graded composite cathode exhibited smaller area-specific resistance and polarization overpotential than the monolayer cathode,thus showing the better electrochemical performance.For graded composite cathode,the area-specific resistance value was about 13.2% lower than that of LBCO at 700 ℃,and the cathodic overpotential was decreased from 51.0 mV to 46.4 mV at a current density of 0.20 A/cm2.

关 键 词：中温固体氧化物燃料电池 梯度复合阴极 热膨胀 电化学性能 

分 类 号：TM911[电气工程—电力电子与电力传动]