【摘要】 采用静电纺丝法制备出均一稳定的LSCF纤维,经过800℃煅烧后形成了纯钙钛矿晶相,并将其构建SOFC阴极。为了减少阴极的极化阻抗,采用Ce0.9Gd0.1O1.95(GDC)浸渍纤维状La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极制备了LSCF-GDC复相阴极。通过SEM和EDS能谱表征,LSCF-GDC复相阴极是由纤维网络状LSCF和纳米GDC晶粒构建而成的。采用对称阴极电池(LSCF+GDC║GDC║LSCF+GDC)测试表明,这种结构的复相阴极具有较低的阻抗和较高的电化学性能。实验表明GDC的浸渍量与复相阴极的电化学性能密切相关,在空气气氛和750℃工作温度下,当GDC与LSCF质量比分别为0∶1、0.17∶1、0.38∶1、0.54∶1时,复相阴极的阻抗分别为0.68Ω·cm2、0.21Ω·cm2、0.09Ω·cm2、0.27Ω·cm2;GDC与LSCF的质量百分比为0.38∶1时,该复相阴极的阻抗最低,在工作温度分别为650℃、700℃和750℃下,其阻抗值分别为0.52Ω·cm2、0.21Ω·cm2和0.09Ω·cm2。更多还原

【Abstract】 The uniform and stable LSCF fiber was synthesized by electrospinning method,it was formed into pure perovskite crystalline phase after sintered at 800 ℃ and was used to build SOFC cathode. In order to reduce the polarization resistance of the cathode,LSCF-GDC composite cathode was prepared by impregnating Ce0. 9Gd0. 1O1. 95( GDC) into the fibrous La0. 6Sr0. 4Co0. 2Fe0. 8O3- δ( LSCF) cathode. The fibernet and composite cathode was formed by fiber-net LSCF and nanometer GDC crystalline powder,which was characterized by SEM and EDS. The composite cathode with this structure possesses lower impedance and higher electrochemical performance,which was shown via the measurement of cathode symmetric cell( LSCF + GDC ║ GDC ║ LSCF + GDC). The close relationship between the amount of impregnated GDC and the electrochemical performance was indicated. The impedance of composite cathode is 0. 68 Ω·cm2,0. 21 Ω · cm2,0. 09 Ω·cm2,0. 27 Ω·cm2respectively under air atmosphere and 750 ℃ working temperature when the weight percent of GDC and LSCF is 0∶ 1,0. 17∶ 1,0. 38∶ 1,0. 54∶ 1. When the weightpercent of GDC and LSCF is 0. 38∶ 1,the impedance of composite is lowest,achieving resistances of 0. 52 Ω·cm2,0. 21 Ω·cm2and 0. 09 Ω·cm2at 650 ℃,700 ℃ and 750 ℃.更多还原