Effect of Ag-precoating on the Electrical Conductivity of 2205-LSM at High Temperature

• Main Authors: Tz-Ling Chen, 陳姿伶
• Other Authors: Chaur-Jeng Wang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/d4ndag

碩士 === 國立臺灣科技大學 === 機械工程系 === 95 === This researches is focus on the behavior and characteristic of oxidation for 2205-LSM at 800 °C and influence on electrical performance at high temperature for silver layer. LSM, Ag-LSM and Ag-Pd-LSM coated on 2205DSS by screen print and sputter was sintered at 1100°C under nitrogen atmosphere for 30 to 90 minutes. As the result, after oxidation at 800 °C for 1000 hours the oxide layer was form at the interface between LSM and 2205DSS. An increase on thickness of oxide layer was observed about 1.56 ± 0.05 µm but there were a small different on resistance measurements about 0.16 to 0.003 Ωcm2 as compared with un-oxidation. During long-term oxidation, formation of Cr-Mn spinel derived from reaction of Cr2O3 form 2205DSS and LSM was increased. Formation Cr-Mn spinel would reduce resistance due to its better conductivity. On resistance measurements at temperature range of 500 to 750 °C, ASR (area specific resistance) for noble metal-LSM coated 2205DSS was decrease with increase of temperature. ASR of the specimens was less than for LSM coated 2205DSS, especially at lower temperature because of noble metal acted as a current collector to provide better pathway for conduction of electron, and low valence cation was diffused to LSM and oxide layer. The different thickness of Silver layer was coated on 2205-LSM by sputter. According the result, ASR for Ag-LSM coated 2205DSS at 500°C was less than for LSM coated 2205DSS at 750°C. This demonstrated that metallic interconnect prepared with Ag-LSM coated 2205DSS could lower working temperature for SOFC.