La0.7Ca0.3CrO3–Ce0.8Gd0.2O1.9 composites as symmetrical electrodes for solid-oxide fuel cells

✍ Scribed by Yingchun Zhang; Qingjun Zhou; Tianmin He

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 736 KB
• Volume: 196
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2010.07.035

✦ Synopsis

La 0.7 Ca 0.3 CrO 3 (LCC)-Ce 0.8 Gd 0.2 O 1.9 (GDC) composites have been investigated as symmetrical electrodes for solid-oxide fuel cells (SOFCs) on La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3-ı (LSGM) electrolyte, where there is no interlayer between anode and electrolyte. LCC oxide is chemically compatible with GDC and LSGM electrolyte at temperatures up to 1200 • C. The electrical conductivity of the LCC-GDC composites decreases with increasing GDC content. The best electrical conductivities of 18.64 S cm -1 in air and 1.86 S cm -1 in H 2 at 850 • C are achieved for an 80 wt% LCC-20 wt% GDC (LCC-GDC20) composite. The thermal expansion coefficients of the LCC-GDC composites increase with increasing GDC content, and are very close to that of the LSGM electrolyte. A cell with a 0.3 mm thick LSGM electrolyte and LCC-GDC20 symmetrical electrodes displays the highest electrochemical performance. The maximum power density is 573 mW cm -2 in dry H 2 and 333 mW cm -2 in humidified commercial city gas containing H 2 S at 900 • C, respectively. These results suggest that the LCC-GDC20 composite can potentially serve as an electrode for symmetrical SOFCs operated on H 2 and commercial city gas containing H 2 S.