摘要
采用溶胶-凝胶法、固相法制备La_(0. 7)Sr_(0. 3)Fe_(0. 7)Co_(0. 2)Ni_(0. 1)O_(3-δ)(LSFCN)中低温固体氧化物燃料电池阴极材料,通过热重-差热分析、X射线衍射、扫描电镜、直流四探针法、热膨胀系数、交流阻抗对材料的结构与性能进行研究。结果表明,2种方法制备的LSFCN均为单一的钙钛矿结构,并且与电解质SDC在950℃以下没发生化学反应,稳定性较好。溶胶-凝胶法制备的阴极粉体颗粒最小、形状规整、结晶度高。在测试温度400~800℃条件下,2种方法合成的阴极材料LSFCN是小极化子导电机制,电导率随着测试温度的升高而增大。溶胶-凝胶法制得的LSFCN的电导率均大于固相法,在800℃时最大达到619. 4S/cm。2种方法制备的LSFCN阴极样品与电解质SDC匹配性好。2种方法制备的LSFCN有利于氧在三相界面的传输,提高了材料的电化学性能。
La_(0.7)Sr_(0.3)Fe_(0.7)Co_(0.2)Ni_(0.1)O_(3-δ)( LSFCN),a cathode material for medium and low temperature solid oxides fuel cell,is prepared by sol-gel method and solid state reaction method,respectively.The structure and properties of the material are measured by thermogravimetry-differential thermal analysis( TG-DTA),X-ray diffractometry( XRD),scanning electron microscopy( SEM),four-probe DC method,thermal expansion coefficient( TEC) and alternatingcurrent impedance.It is shown that LSFCN prepared by two methods both have a single perovskite structure and do not react with the electrolyte SDC during 950℃ calcination,meaning a good stability.LSFCN prepared by sol-gel method has a smaller particle size,a more regular shape and a higher crystallinity.Both LSFCN by two methods exhibit a conductivity mechanism of small polaron at the test temperature of 400-800℃,their conductivities increase with the increase of the test temperature.The conductivity of LSFCN prepared by sol-gel method is higher than that of LSFCN prepared by the solid state reaction method. The maximum conductivity of LSFCN reaches 619. 4 S·cm~(-1) at 800℃. LSFCN cathode samples prepared by the two methods have a good match with SDC electrolyte,and both are favorable for oxygen transfer through three-phase interface,which can improve the electro chemical properties of the materials.
引文
[1]Harumi,Yokokawa.Report of five-year NEDO project on durabilit/reliability of SOFC stacks[J]. ECS Transactions,2013,57(1):299-308.
[2]Kenji Horiuchi.Current status of national SOFC projects in Japan[J].ECS Transactions,2013,57(1):3-10.
[3]Suzuki M,Takuwa Y,Inoue S,et al.Durability verification of residential SOFC CHP system[J]. ECS Transactions,2013,57(1):309-314.
[4]黎朝晖,侯书恩,庞松.中温固体氧化物燃料电池阴极材料La0. 7Sr0. 2Co0. 1CuO3-δ的制备与表征[J].硅酸盐通报,2010,29(1):33-37.
[5]Shiono M,Kobayashi K,Nguyen T L,et al.Effect of CeO2interlayer on Zr O2electrolyte/La(Sr)CoO3cathode for low temperature SOFCs[J].Solid State Ionics,2004,170(1/2):1-7.
[6]龚明光,陆丽华,张华,等.低温自燃烧法合成La2Ni O4阴极材料及其性能[J].硅酸盐通报,2009,28(1):38-43.
[7]Toshiaki Matsui,Siqi Li,Hiroki Muroyama,et al. Electrochemical property of solid solutiona formed in(La,Sr)(Co,Fe)O3-δcathode/doped-CoO2interlayer/Y2O3-Zr O2electrolyte system during operation of solid oxide fuel cells[J]. Solid State Ionics,2017,300:135-139.
[8]Royer S,Duprez D,Kaliaguine S.Oxygen mobility in La CoO3perovskites[J].Catalysis Today,2006,112(1-4):99-102.
[9]毛宗强.燃料电池[M].北京:化学工业出版社,2005:7-11.
[10]Wang S,Jiang Y,Zhang Y,et al. Electrochemical performance of mixed ionic-electronic conducting oxide as anode for solid oxide fuel cell[J].Solid State Ionics,1999,120:75-84.
[11]江金国,崔崇La0. 6Sr0. 4Fe0. 8Co0. 2O3-δ系阴极材料制备及表征[J].材料科学与工程学报,2004,24(3):352-354.
[12]Che Xiangli,Shen Yu,Li Hang,et al. Assessment of LnBaCo1. 6Ni0. 4O5+δ(Ln=Pr,Nd,and Sm)double-perovskites as cathodes for intermediate-temperature solid-oxide fuel cells[J].Journal of Power Sources,2013,222(15):288-293.
[13]Wei Bo,LüZhe,Jia Dechang,et al.Thermal expansion and electrochemical properties of Ni-doped GdBaCo2O5+δdouble-perovskite type oxides[J].International Journal of Hydrogen Energy,2010,35(8):3775-3782.
[14]李蕾.Fe和Ni置换钴的双钙钛矿中温固体氧化物燃料电池阴极材料的性能研究[D].长春:吉林大学,2016:23-25.
[15]李强,赵辉,曾旭,等.固体氧化物燃料电池La SrCu0. 7Fe0. 3O4阴极材料的电化学性能研究[J].黑龙江大学自然科学学报,2013,30(6):769-770.
[16]靳宏建,王欢,蒋晓勇,等.Sm BaCo2O5+δ-Ce0. 8Sm0. 2O1. 9复合阴极的热膨胀及电化学性能[J].硅酸盐通报,2012,31(4):790-793.
[17]赵伟杰,张晶.甘氨酸-硝酸盐法制备La2FexCu1-xO4及其氧敏性能[J].硅酸盐通报,2013,32(3):407-408.
[18]Yu Shancheng,He Shoucheng,Chen Han,et al.Effect of cacination temperature on oxidation state of cobalt in calcium cobaltite and relevant performance as intermediate-temperature solid oxide fuel cell cathodes[J].Journal of Power Sources,2015,280:581-587.
[19]胡智,黄晓巍,陈杨辉.EDTA-甘氨酸法制备SmBaCo2O5+δ阴极材料及其性能[J].物理化学学报,2013,29(12):2585-2591.
[20]吉冬冬,朱正玉,田长安,等.固体氧化物燃料电池电解质材料La2Mo2-xMnxO9-δ的制备与性能研究[J].中国陶瓷,2018,54(2):31-32.
[21]何志平.SmBaCoCuO5+δ作为SOFC阴极材料的制备和性能研究[J].中国陶瓷工业,2015,22(6):17-18.
[22]张磊磊,常莹,黄金华等.中温SOFC复合阴极材料BSCN0. 6-30%GDC的表征[J].辽宁石油化工大学学报,2014,34(2):6-7.
[23]Ding Xifeng,Cui Chong,Guo Lucun.Thermal expansion and electrochemical performance of La0. 7Sr0. 3CuO3-δ-Sm0. 2Ce0. 8O2-δcomposite cathode for IT-SOFCs[J].Journal of Alloys and Compounds,2008,481(1-2):845-850.
[24]Hwang Hae Jin,Moon Ji Woong,Lee Seunghun,et al.Electrochemical performance of LSCF-based composite cathodes for intermediate temperature SOFCs[J].2005,145(2):243-248.
[25]Leng Yongjun,Chan Siew Hwa,Liu Qinglin.Development of LSCFGDC composite cathodes for low-temperature solid oxide fuel cells with thin film GDC electrolyte[J]. International Journal of Hydrogen Energy,2008,33(14):3808-3817.
[26]徐红梅,张华,李恒等.纳米结构LSCD-SDC复合阴极的制备及其氧还原机理研究[J].无机材料学报,2017,4(32):379-385.
[27]Dumaisnil K,Fasquelle D,Mascot M,et al.Synthesis and characterization of La0. 6Sr0. 4Fe0. 2Co0. 8O3films for solid oxide fuel cell cathode[J].Thin Solid Films,2014,553:89-92.