Enhanced Activity of Pr6O11and CuO Infiltrated Ce0.9Gd0.1O2Based Composite Oxygen Electrodes

Autor: Khoshkalam, Mohamad, Faghihi-Sani, Mohammad Ali, Tong, Xiaofeng, Chen, Ming, Hendriksen, Peter Vang
Zdroj: Journal of the Electrochemical Society; January 2020, Vol. 167 Issue: 2 p024505-024505, 1p
Abstrakt: Operation of solid oxide fuel/electrolysis cells (SOFC/SOEC) at high temperatures (T > 850 °C) is accompanied by degradation phenomena, which severely affect the operational lifetime of the cell. Degradation processes are expected to occur slower at low temperatures. However, significant reduction in electrocatalytic activity of the oxygen electrode, is one of the major challenges in decreasing the operating temperature down to 500 °C–650 °C. Recently, Pr6O11infiltrated Ce0.9Gd0.1O2(CGO) based electrodes have been proposed to realize high electrochemical performance at intermediate temperature. In this study, Pr-oxide has been infiltrated into a well performing sub-micro La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2(LSCF/CGO) composite electrode as well as a poorly performing LaNi0.6Fe0.4O3/Ce0.9Gd0.1O2(LNF/CGO) electrode. The results are compared with Cu-oxide infiltration. Formation of Pr rich oxide surface nanostructures, resulted in a pronounced reduction of polarization resistances by a factor of 3 in state of the art LSCF/CGO electrodes. Even better performances were achieved in Pr6O11infiltrated LNF/CGO, demonstrating low polarization resistances of 0.074 ∓ 0.002 and 0.146 ∓ 0.002 Ω.cm2at 600 °C and 550 °C, respectively. Low degradation rates were observed over a 200 h durability test at 650 °C, illustrating the potential of Pr6O11infiltrated CGO oxygen electrodes for intermediate temperature SOFC/SOEC application.
Databáze: Supplemental Index