Ce_(0.8)Sm_(0.2)O_(1.9)中间层对La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3-δ)阳极电化学性能的影响

Effects of Ce_(0.8)Sm_(0.2)O_(1.9) interlayer on electrochemical performances of La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3-δ) anode

通过固相反应法合成La0.75Sr0.25Cr0.5Mn0.5O3-δ(LSCM)以及Ce0.8Sm0.2O1.9(SDC)粉体。采用X线衍射仪(XRD)、扫描电子显微镜(SEM)、电化学阻抗谱法、循环伏安法和热膨胀法分别对试样的晶体结构、化学相容性、微观结构、电化学性能和热膨胀系数进行了研究。结果表明:LSCM阳极与SDC之间具有良好的化学相容性;含有SDC中间层的LSCM阳极显示出更小的比表面电阻和极化过电位;在800℃H2气氛下,含有SDC中间层的LSCM阳极的比表面电阻为0.76Ω.cm2,与单层LSCM阳极相比下降了72.1%,阳极极化过电位(电流密度为0.05A/cm2)下降了70.4%;SDC中间层的加入会导致热膨胀不匹配率的略微增大。

The La0.75Sr0.25Cr0.5Mn0.5O3-δ （ LSCM ） anode and Ce0.8Sm0.2O1.9 （ SDC ） powders were synthe- sized by a solid state reaction method. The crystal structure, chemical compatibility, microstructure, elec- trochemical performances, and thermal expansion coefficient were investigated by X-ray diffraction （XRD） , scanning electron microscopy （SEM） , electrochemical impedance spectra （EIS） , cyclic voham- metry techniques, and thermo dilatometry. Results showed that SDC powder had good chemical compatibil- ity with LSCM anode. LSCM anode with SDC interlayer showed much smaller area-specific resistance （ASR） and polarization overpotential than the LSCM anode. ASR of LSCM anode with SDC interlayer was 0. 76 Ω. cm2, about 72. 1% lower than that of LCSM anode at 800℃ in H2, and the anodic overpotential was reduced by 70.4% at a current density of 0.05 A/cm2. The addition of SDC interlayer between LSCM anode and electrolyte could slightly increase the mismatch of thermal expansion.