Abstract
In this work, abundant oxygen vacancies are introduced into NdBaCo2O5+δ (NBCO) by partial substitution of cobalt to facilitate the electrochemical activity of ORR. The oxygen vacancy concentration of NdBaCo1.8Sc0.2O5+δ (NBCSc-2) is more than twice as that of NdBaCo2O5+δ. The increased oxygen surface exchange, bulk diffusion coefficients and adequate conductivity for NBCSc-2 can be responsible for the decrease of oxygen ion transfer activation energy. Consequently, the NBCSc-2 cathode shows a significantly reduced polarization impedance of 0.035 Ω cm2 at 700 °C, which is only about 35% of NBCO. We also investigate the influence of the doping strategy on the stability of cathode. Thus, the enhanced ORR kinetics and high durability make NBCSc-2 as potential cathode material for solid oxide fuel cells.
Original language | English |
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Article number | 228017 |
Journal | Journal of Power Sources |
Volume | 459 |
DOIs | |
Publication status | Published - 31 May 2020 |
Externally published | Yes |
Keywords
- Oxygen bulk diffusion coefficient
- Oxygen surface exchange coefficient
- Oxygen vacancy
- SOFC cathode