以金屬La促進NiO-SDC陽極製備SOFC並以甲烷為燃料 學生:連昶富 日期:103/11/03
Introduction 1.在Ni為基材的陽極中添加MgO, CaO, La2O3與Li2O3等金屬氧 化物可讓其在甲烷與烴下的穩定性與催化性獲得改善。 2. 當添加少量的La於Ni-YSZ陽極中可以有效的改善NiO的燒 結狀況與增進NiO與YSZ的界面接觸。 3.本篇研究中，在NiO-SDC陶瓷陽極中添加少量的La以增進 NiO的催化活性與穩定性並在低於600℃的操作溫度進行電 性測試。
Experimental -1 陽極製備 Ni(NO3) glycine NiO powder heated at 90 ℃ until a gel was formed heated on an electronic stove igniting to flame. calcined at 850 ℃ for 4 h NiO powder Ni0.95La0.05O, SDC(鍛燒800 ℃, 2h)以相同方式製備
Experimental -2 單電池製備 Ni(La)O–SDC (55:45 wt.%)) SDC SSC/SDC 1340 ◦C for 5 h, 共壓 SDC 1000 ◦C for 2 h, 塗佈 SSC/SDC (70:30 wt.%))
Results and discussion Fig. 1. XRD patterns of NiO and Ni0.95La0.05O powders. (a) Sintered at 1340 ◦C and (b) after reduction at 700 ◦C in pure H2 for 4 h. (n) NiO, (l) La2NiO4, (N) Ni, and (o) La2O3.
Fig. 2. SEM images of the NiO (a) and Ni0.95La0.05O (b) powders
Fig. 3. I–V and I–P curves of the cells in 3% H2O humidified methane fuel from 500 to 600 ◦C. (a) NiO–SDC anode cell and (b) Ni0.95La0.05O–SDC anode cell.
Fig. 4. Electrochemical impedance spectra of the cells in 3% H2O humidified CH4 from 500 to 600 ◦C. (a) NiO–SDC anode cell and (b) Ni0.95La0.05O–SDC anode cell.
Fig. 5. Voltage of the cells versus time at a constant current density of 0.44 A cm−2 at various temperatures. (a) 600 ◦C, (b) 550 ◦C, and (c) 500 ◦C.
Fig. 6. Comparison of the electrochemical impedance spectra of different cells in 3% H2O humidified H2 and CH4 fuels at 600 ◦C.
Fig. 7. Stability of the cells operated in 3% H2O humidified CH4 at a constant current density of 0.44 A cm−2 at 600 ◦C.
Fig. 8. SEM images and EDX spectra of the anode of different cells from cross section. (a) as prepared NiO–SDC anode (b) as prepared Ni0.95La0.05O–SDC anode (c) NiO–SDC anode after operated in 3% H2O humidified CH4 for 160 min (d) Ni0.95La0.05O–SDC anode after operated in 3% H2O humidified CH4 for 480 min
(e) comparison of EDX spectra of NiO–SDC anode before and after operated in 3% H2O humidified CH4 (f) comparison of EDX spectra of Ni0.95La0.05O–SDC anode before and after operated in 3% H2O humidified CH4.
Conclusions 1.由結果證實添加5 mol%La於NiO–SDC可提高OCV值、電性表現與電池穩定性。 3.Ni0.95La0.05O–SDC有較小的粒子與較均勻的分散可改善其電性表現