Improved oxide-ion conductivity by substitution in Dion-Jacobson phases

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20483
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0401:Materials engineering, chemical engineering, and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: zhang wenrui 東京工業大学, 理学院, 特任助教 (20911853)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: イオン伝導体 / 結晶構造 / 固体酸化物方燃料電池 / 固体電解質 / 中性子回折

Outline of Final Research Achievements

We present the first report on the preparation, electrical and structural properties of oxide-ion conducting Dion-Jacobson phases CsBi1.9M0.1Ti2NbO9.95 (M = Mg, Ca, Sr and Ba) and CsBi2Ti2-xNb1+xO10+x/2 (x = 0.1, 0.2, -0.1 and -0.2). It was found that partial substitution of Bi3+ by Sr2+ improves the conductivity of CsBi2Ti2NbO10. The electrical conductivity of CsBi1.9Sr0.1Ti2NbO9.95 is approximately 2 times higher than that of CsBi2Ti2NbO10 at 600-900 °C. The improvement of oxide-ion conductivity in CsBi1.9Sr0.1Ti2NbO9.95 can be attributed to the increase of the carrier (oxygen vacancy) concentration and small size mismatch between the dopant Sr and host Bi cations.This study demonstrates the successful improvement of oxide-ion conductivity by the substitution in Dion-Jacobson phase, which would develop the science and technology of Dion-Jacobson type oxide-ion conductors.

Free Research Field

無機材料物性

Academic Significance and Societal Importance of the Research Achievements

高い酸化物イオン伝導度を示す新型酸化物イオン伝導体の発見により、Dion-Jacobson型酸化物イオン伝導体という研究分野が生まれると考えられる。また、新たな応用に向けた道を切り開くと期待でき、学術的に意義深い。また、本研究は固体酸化物形燃料電池や酸素濃縮器の高性能化や、新しい酸化物イオン伝導体や電子材料の開発を促進すると考えられ、社会的にも意義深い。