| Autor: |
Lim T; School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea., Yun SS; School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea.; Electronic Materials Business Unit II Manufacturing Technology Team, Dongjin Semichem Co., Ltd., Incheon 22824, Republic of Korea., Jo K; School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea., Lee H; School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea. |
| Abstrakt: |
The oxygen vacancy formation behavior and electrochemical and thermal properties of Ba 0.5 Sr 0.5 Fe 1-x Mn x O 3-δ (BSFMnx, x = 0-0.15) cathode materials were investigated. For thermogravimetric analysis, the weight decreased from 1.98% (x = 0) to 1.81% (x = 0.15) in the 400-950 °C range, which was due to oxygen loss from the lattice. The average oxidation state of the B-site increased, the O ads /O lat ratio decreased, and the binding energy of the O lat peak increased with Mn doping. These results indicate that Mn doping increases the strength of the metal-oxygen bond and decreases the amount of oxygen vacancies in the lattice. The electrical conductivity of BSFMnx increased with the temperature due to the thermally activated small-polaron hopping mechanism showing a maximum value of 10.4 S cm -1 (x = 0.15) at 450 °C. The area-specific resistance of BSFMn0.15 was 0.14 Ω cm 2 at 700 °C and the thermal expansion coefficient (TEC) gradually decreased to 12.7 × 10 -6 K -1 , which is similar to that of Ce 0.8 Sm 0.2 O 2 (SDC) (12.2 × 10 -6 K -1 ). Mn doping increased the metal-oxygen bonding energy, which reduced the oxygen reduction reaction activity but improved the electrical conductivity and thermal stability with SDC. |
