田长安
,
曹严
,
尹奇异
,
谢劲松
,
王春阳
,
杨娟
,
王明
,
阳杰
硅酸盐通报
采用溶胶-凝胶法制备了电解质材料La1.9Ba0.1Mo1.9 Al0.1O8.8(LBMA),通过热重-差示扫描量热分析(TG-DSC)、X射线衍射(XRD)、透射电镜(TEM)、扫描电镜(SEM)和电化学阻抗谱(EIS)等方法对样品进行测试研究.研究表明干凝胶经700℃煅烧处理即可得到立方相氧化物LBMA,煅烧后的粉体为分散性较好的球形纳米颗粒,平均粒径约为35 nm.SEM分析和致密度研究表明溶胶-凝胶法制备的粉体具有良好的烧结性能,在1100℃烧结2h能得到相对密度高于98％的致密的陶瓷烧结体.电化学性能研究表明LBMA具有较高的离子电导率,1100℃烧结的LBMA电解质在800℃时电导率达到17.87 mS/cm,电导活化能为1.22 eV,其有望应用于中低温固体氧化物燃料电池.
关键词:
固体氧化物燃料电池
,
La2Mo2O9
,
溶胶-凝胶
,
电导率
李相虎
,
李丹
材料导报
采用固相反应法制备了氧离子导体La2MO2-yAlyO9-δ(y=0、0.1、0.2、0.3)陶瓷样品.用XRD表征了其晶体结构,并用交流阻抗谱方法研究了样品在还原气氛中(5%Hz/Ar)的化学稳定性.结果表明,La2Mo1.9Al0.1-O9-δ样品在还原气氛中的化学稳定性最好,当Al的掺杂量达到10%(y=0.2)时,样品就会被分解,同时化学稳定性能降低.
关键词:
氧离子导体
,
La2Mo2O9
,
化学稳定性
,
电导率
周德凤
,
叶俊峰
,
朱建新
,
孟健
功能材料
以La2Mo1.7W0.3O9为本体,在La位进行碱土金属掺杂,采用溶胶-凝胶方法合成新型氧离子导体La1.84R0.16Mo1.7 W0.3O8.92(R=Ca2+、Sr2+、Ba2+).应用示差热分析(DTA)、X射线衍射(XRD)、拉曼光谱(Raman)等手段对氧化物进行结构表征,交流阻抗谱测试电性能.结果表明:掺杂改善了本体导电性能的同时,保持了La2Mo1.7W0.3O9抑制La2Mo2O9相变的功能;碱土离子的掺杂,在体系中引入了氧空位,有利于氧离子扩散,提高氧离子导电性,773K时Ba2+掺杂体系的电导率为1.0×10-4S/cm,高于本体的电导率(5.0×10-5/cm).
关键词:
固体电解质
,
氧离子导体
,
掺杂
,
La2Mo2O9
Jianxin WANG
,
Qin WANG
,
Xianping WANG
,
Chun LI
,
Qianfeng FANG
材料科学技术（英文）
A cost-effective technique, including nanocrystalline powder preparation using a modified Pechini method and a two-step low-temperature sintering route, was developed for the synthesis of high performance La2Mo2O9-based oxide-ion conductors. The optimum parameters of the compaction pressure, the first step and the second step sintering temperatures for the synthesis of fine grained, high density and uniform La2Mo2O9-based oxide-ion conductors were determined by a series of sintering experiments. High density and uniform sintered La2Mo2O9 samples with average grain size from 0.8 to 5 μm and La1.96K0.04Mo2O8.96 sample with average grain size as small as 500 nm were synthesized by using this cost-effective method. The impedance measurement results show that the as-fabricated La2Mo2O9-based ceramics possess much higher ionic conductivity than that obtained by solid state reaction method. It is found that in the range of 0.8{5 μm the grain size of dense La2Mo2O9 samples prepared from the nanocrystalline powders has little influence on their conductivities.
关键词:
Oxide ion conductor
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