| 摘要: | 本論文在以低廉之鑭鍶鋁鎂(LSAM)氧化物和鑭鍶鎵鎂(LSGM)氧化物互相混合，製作LSGM-LSAM混和，探討其作為固態氧化物燃料電池電解質之可行性。首先依溶膠凝膠法來製備La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM)與La0.9Sr0.1Al0.9Mg0.1O3 (LSAM)兩種粉末，再分別以0、25、50、75及100 wt.%等不同之比例將LSAM粉末與LSGM互相混和，燒結後探討此混和材料之結晶結構、形貌、導電率。隨後，將混合粉末製作固態氧化物燃料電池，進行測試。結果顯示：含25 wt.% LSAM之混和電解質，其電池功率密度約為純LSGM電解質電池之91%。
上述含25 wt.% LSAM之混和電解質，分別摻雜1.0 mol % Cr與1.0 mol % Zn元素，在800 oC下量測離子導電率結果顯示：摻雜Cr電解質之離子導電率下降(0.038 S/cm < 0.073 S/cm)，且導電活化能降低(1.37eV < 1.56 eV)；摻雜Zn電解質之離子導電率增高(0.088 S/cm > 0.073 S/cm)，導電活化能降低(1.35eV < 1.56 eV)。摻雜Cr電解質之熱膨脹係數為12.6×10-6/K；摻雜Zn電解質則為22.2×10-6/K，後者與陰極之膨脹係數(20.6×10-6/K)匹配度較高。隨後，製作陽極支撐型SOFC電池，經800 oC量測電池功率，結果顯示:摻1.0 mol % Zn含25 wt.% LSAM混和電解質之電池，其功率較高(173.6 mW/cm2 > 124.6 mW/cm2)。經濟性評估顯示：摻雜1.0 mol % Zn含25 wt.% LSAM混和電解質製作之SOFC，電池功率並不比純LSGM電池遜色，但成本降低約23.7%，，預期具有取代純LSGM電解質製作固態氧化物燃料電池之潛力，創造更高之經濟效益。
;In this study, low-cost lanthanum strontium aluminum magnesium (LSAM) oxide and lanthanum strontium gallium magnesium (LSGM) oxide are mixed with each other to make LSGM-LSAM composite, and explore its feasibility as a solid oxide fuel cell electrolyte. First, prepare La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) and La0.9Sr0.1Al0.9Mg0.1O3 (LSAM) powders by the sol-gel method, and then mix the LSAM powder and LSGM in different ratio (0, 25, 50, 75 and 100 wt.%), and discuss the crystal structure, morphology, and conductivity of the mixed material after sintering. Subsequently, the mixed powder was made into a solid oxide fuel cell for testing. The results show that the power density of the mixed electrolyte containing 25 wt.% LSAM is about 91% of that of the pure LSGM electrolyte support cell.
The above-mentioned mixed electrolyte containing 25 wt.% LSAM was doped with 1.0 mol% Cr and 1.0 mol% Zn respectively. The ion conductivity measured at 800 oC showed that the ionic conductivity of the doped Cr electrolyte decreased (0.038 S/ cm <0.073 S/cm), and the activation energy of conduction decreases (1.37eV <1.56 eV); the ionic conductivity of doped Zn electrolyte increases (0.088 S/cm> 0.073 S/cm), and the activation energy of conduction decreases (1.35eV < 1.56 eV). The thermal expansion coefficient of the doped Cr electrolyte is 12.6×10-6/K; the doped Zn electrolyte is 22.2×10-6/K, and the latter was more suitable with the expansion coefficient of the cathode (20.6×10-6/K). Subsequently, an SOFC anode-supported cell was fabricated, and the power density was measured at 800 oC. The results showed that: doped with 1.0 mol% Zn and 25 wt.% LSAM mixed electrolyte has a higher power (173.6 mW/cm2> 124.6 mW/cm2 ). Economic evaluation shows that: SOFC doped with 1.0 mol% Zn and 25 wt.% LSAM mixed electrolyte, power density is not inferior to pure LSGM cell, but the cost is reduced by about 23.7%, and it is expected to replace pure LSGM electrolyte to produce solid oxide The potential of fuel cells creates higher economic benefits. |
