Improvement of oxide ionic conductivity of Si-deficient lanthanum silicate for realization of low temperature operation of SOFC

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05009
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Niihama National College of Technology
• Principal Investigator: Susumu Nakayama 新居浜工業高等専門学校, 生物応用化学科, 教授 (50300637)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: アパタイト酸化物イオン伝導体 / 固体酸化物型燃料電池

Outline of Final Research Achievements

By orienting the Si-deficient lanthanum silicate on the c-axis, an ionic conductivity of 0.03 S cm-1 at 500℃ was achieved. By increasing the c-axis orientation, the ionic conductivity of the electrolyte and the exchange of oxide ions between the electrolyte and the electrode can be improved. By improving the ionic conductivity and reducing the electrolyte-electrode interface resistance, the maximum power density of the electrolyte-supported SOFC single cell using the c-axis oriented ceramic with a thickness of 1 mm was around 70 mW cm-2 at 500℃.

Free Research Field

無機化学

Academic Significance and Societal Importance of the Research Achievements

従来、500℃以下で最大出力100 mW・cm-2を超える電解質支持型SOFC実現は難しいと考えられてきた。電解質を限界まで薄くできるアノード支持型は電気的損失を低減できる利点があるものの、構造、製作および長期安定性では電解質支持型が有利である。イオン伝導の異方性を有し、c軸配向により500℃以下で高い酸化物イオン導電率が得られるアパタイト酸化物イオン伝導体は500℃以下で作動できる電解質支持型SOFC実用化の道を拓くことになる。