Research On Characteristics Of The Electrolyte LSGM/Anode Interface Products

La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85 ( LSGM ) is a perfect electrolyte for the middle- temperature solid oxide fuel cell. In this paper, LSGM and anode materials of the SOFC are prepared by technology of lapping - forming with pressure - sintering. The anode materials are prepared by mixture with LSGM and Ni2O3 or CeO2 according to different proportion. The characteristics of the LSGM /anode interface products are investigated by using the method of the simulation of interface products, the interface products of the electrolyte LSGM/ anode are formed by mixing the electrolyte LSGM and the materials of anode according to 1:1 and sintering them.The crystal structure and DC, AC conductivity of the products of the interface of electrolyte/ anode are studied. The pattern and the size of the grain are examined by the SEM. Some big and sparse holes are seen on the surface of LSGM specimen, it's a advantage for the condition of oxygen-ion transmission. The holes on the surface of Ni2O3-doped interface products specimen are small and dense, the structure of the specimen is compact, it's favorable for the transmission of oxygen-ion and the conductivity of oxygen-ion is high in this specimen. Some crevice is found on the surface of CeO2-doped specimen, so the structure is not stable. XRD is used to analyze the phase and product. The results indicated that the LSGM is a rhombohedral phase and perovskite structure which is the same to the LaGaO3. No new peak of diffraction is found in these materials, so no new products is generated in the material except for the mixture of LSGM, Ni2O3 and CeO2. Two probe method is used in the testing of DC conductivity and AC conductivity. The results of DC conductivity showed that conductivity of the specimen increased with rising of temperature. Conductivity is high in the range of 600 C -800 C. The AC conductivity of the specimen is not variable in the region of low and middle frequency, which is from10Hz to100KHz. The response of AC conductivity is sharp in the range which frequency is higher then 100KHz, the AC conductivity of LSGM and CeO2-doped specimen increased with the rise of frequency while Ni2O3-doped specimen reduced when the frequency is above 100KHz.