Electrical conductivity and electrochemical performance of cobalt-doped BaZr0.1Ce0.7Y0.2O3−δ cathode

✍ Scribed by Lei Yang; Shizhong Wang; Xiaoyuan Lou; Meilin Liu

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 711 KB
• Volume: 36
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.11.053

✦ Synopsis

To develop efficient cathode materials for solid oxide fuel cells (SOFCs) based on Ba (Zr 0.1 Ce 0.7 Y 0.2 )O 3Àd (BZCY) electrolyte, we have examined a series of cobalt-doped BZCY samples with the intended composition of BaZr 0.1 Ce 0.7 Y 0.2Àx Co x O 3Àd (where x ¼ 0, 0.02, 0.05, 0.075, 0.1, 0.2). It is found that the solubility of cobalt is less than 10 mol% and the electrical conductivity of BaZr 0.1 Ce 0.7 Y 0.2Àx Co x O 3Àd decreased with the content of cobalt within this solubility. When the content of cobalt is greater than its solubility, a BaCoO 3 -based phase forms, which markedly increases the conductivity of the sample (e.g., 2.48 S/cm for a composite material with an intended composition of BaZr 0.1 Ce 0.7 Co 0.2 O 3Àd at 700 C).

Typical cells with the cobalt-doped BZCY cathode display much-improved performance than cells with other transition metal doped barium cerate ever reported, yielding a polarization resistance of 0.085 U cm 2 at 750 C.