微波辅助溶胶凝胶法合成La_(0.8)Sr_(0.2)Co_(0.5)Fe_(0.5)O_3阴极材料及性能研究(英文)  

Synthesis and Performances of La_(0.8)Sr_(0.2)Co_(0.5)Fe_(0.5)O_3 Cathode by Microwave Assisted Sol-Gel Method

作　　者：刘石明[1] 邢长生[1] 钱晓良[1] 肖建中[1] 

机构地区：[1]华中科技大学环境科学与工程系,湖北武汉430074

出　　处：《稀有金属材料与工程》2008年第A02期486-490,共5页Rare Metal Materials and Engineering

摘　　要：使用一种新的理想方法——微波辅助溶胶凝胶法,在35 min内快速制备了钙钛矿结构的La0.8Sr0.2Co0.5Fe0.5O3(LSCF)纳米材料:以8%Y2O3稳定化的ZrO2(YSZ)为电解质,La0.8Sr0.2Co0.5Fe0.5O3为阴极,铂电极为阳极,制备了LSCF/YSZ/Pt固体氧化物电池。采用X射线粉末衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、BET和电化学阻抗谱(EIS)等技术研究了La0.8Sr0.2Co0.5Fe0.5O3材料的成相过程、粉晶结构、电极/电解质微观相貌和电池电化学性能。结果发现经过1min的微波辐射,凝胶开始分解,3 min后有钙钛矿相生成,到35 min时形成了完整的钙钛矿晶相,相应粉体的粒径和比表面积分别为22.7 nm和38.9 m2/g:在1094 K,0 mV偏置电压下电极/电解质界面电阻为0.775 Q·cm2,活化能为2.34 eV。研究发现,偏置电压越大则活化能越低。Perovskite structured La0.8Sr0.2Co0.5Fe0.5O3 （LSCF） cathode materials were prepared by a microwave assisted sol-gel process. The formation and crystalline structure of powders derived from the chelate solution were analyzed by X-Ray diffraction （XRD）, Fourier transformation infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM） and BET techniques. In addition, the electrochemical performances of LSCF cathode for zirconia-based solid oxide fuel cells were investigated by Electrochemical Impedance Spectroscopy （EIS） on a three electrode cell, where the sample in this study was the LSCF working electrode and two platinum electrode used as counter and reference electrode. The results show that the gel began to decomposed after about 1 min microwave treatment, then transformed into a great quantity of LSCF and a pure LSCF Perovskite single phase when microwave treated for 3 min and 35 min respectively. Typical mean particle diameters and specific surface of LSCF powders are 18 nm and 38.9 m2/g. The LSCF/YSZ interracial resistance （R3） is 0.775Ω.cm2 measured at 1094 K without a DC bias. The LSCF/YSZ interracial resistance activation energies is 2.34 eV, The DC bias has a great effect on the interracial resistance activation energies, as larger DC bias gives rise to lower activation energies.

关 键 词：微波 固体氧化物燃料电池 溶胶凝胶法 电化学阻抗谱 

分 类 号：O614.31[理学—无机化学]