Enhancement of fuel cell electrode kinetics by control of Fermi level

2014 Fiscal Year Final Research Report

• Project/Area Number: 25820334
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Inorganic materials/Physical properties
• Research Institution: Kyushu University
• Principal Investigator: PERRY Nicola 九州大学, カーボンニュートラル・エネルギー国際研究所, 助教 (90645665)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: SOFC / electrode / thin film / surface / oxygen exchange / defect chemistry / doping / electronic structure

Outline of Final Research Achievements

Solid oxide fuel cells (SOFCs) offer clean, efficient energy conversion, but their cost needs to be lowered by increasing their efficiency and durability. In this work I sought to understand and improve the efficiency of the SOFC cathode, by modifying how rapidly it could incorporate oxygen from the gas. I tested the hypothesis that increasing the electron concentration of the cathode could improve its oxygen surface exchange rate by starting with the model cathode material Sr(Ti,Fe)O3-x and introducing "donor" elements like La which can donate electrons to the material. From several experiments I developed a "defect chemical model" showing how many electrons were generated by this process. I fabricated dense thin film cathodes with different La concentrations and determined their surface exchange rate by new techniques, including "optical transmission relaxation" to see how the La concentration impacted their efficiency. The chemo-mechanical durability was also investigated.

Free Research Field

Materials Science & Engineering / Ceramics