Environmental Degradation of Perovskite Electrode Surfaces in Solid Oxide Fuel Cells

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05299
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: Kyushu University
• Principal Investigator: Staykov Aleksandar 九州大学, カーボンニュートラル・エネルギー国際研究所, 准教授 (80613231)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: SOFC / electrochemistry / electrode reactions / perovskites / DFT

Outline of Final Research Achievements

The project addressed the problem of environmental degradation of SOFCs electrodes operating in air conditions. Air consists of N2, O2, CO2, H2O and other molecules. While N2 is mostly inert, CO2 and H2O can be significant competitors for adsorption sites on the electrode surface. We have investigated the co-adsorption of H2O and CO2 with O2. We understood that H2O has promoting effect for oxygen exchange while CO2 leads to the formation of carbonate phase that blocks the electrode surface. H2O and CO2 are natural competitors and H2O on the surface can significantly delay or suppress the carbonate phase formation. At low air humidity the carbonate phase is formed, at high air humidity the carbonate phase is suppressed. Our theoretical results were verified by experimental observation of wet and dry CO2 interacting with the electrode surface. We have compared theoretical and experimental IR spectra and we monitored the formation of the carbonate. Results are published: J. Mater. Chem. A

Free Research Field

materials science

Academic Significance and Societal Importance of the Research Achievements

Our results were the first to explain the H2O and CO2 competition on the perovskite electrodes surfaces. We have concluded that humidified air can suppress the formation of carbonate phase and as a result extend the electrodes' durability.