改进埋烧法制备La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_3电解质及其性能

Preparation of La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_3 electrolyte by improved embeded sintering method and its properties

采用改进埋烧法制备出高致密度和优异中温离子导电性能的La0.8Sr0.2Ga0.8Mg0.2O3(LSGM)固体电解质。用X射线衍射、扫描电镜分析样品的物相和表面形貌,采用阿基米德排水法进行试样的密度测试,用交流阻抗技术研究样品的电性能。研究结果表明:在1 400 ℃以上烧结形成单一稳定的钙钛矿结构。随着烧结温度的提高和保温时间的延长,样品致密度增大,导电性能提高,在1 470 ℃烧结18 h的样品均达到最佳值,其相对密度为98%,在800 ℃时电导率达到0.11 S·cm-1。该体系电导率与温度的关系分区符合Arrhenius定律。

La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) had been successfully made by improved embeded sintering method, which has high density and superior intermediate temperature oxide-ion conductivity. The structure, morphology, density and electrical properties of the LSGM samples were investigated by XRD, SEM, the archimedes method, and AC impedance respectively. The results revealed that the single perovskite structure formed after sintering temperature above 1 400 ℃. The densification and conductivity of the samples increased gradually with increasing of the sintering temperature and duration of the sintering time, which reached an optimum value at 1 470 ℃ for 18 h. LSGM electrolyte exhibited a relative density of 98% and an oxygen ionic conductivity of 0.11 S·cm-1 at 800 ℃ at this point. The relationship between electrical conductivity and temperature is found to conform to arrhenius law in two different regions.