Degradation of Anode Supported SOFCs as a Function of Temperature and Current Load

Abstract

The degradation behavior of anode supported solid oxide fuel cells ͑SOFCs͒ was investigated as a function of operating temperature and current density. Degradation rates were defined and shown to be mainly dependent on the cell polarization. The combination of a detailed evaluation of electrochemical properties by impedance spectroscopy, in particular, and post-test microscopy revealed that cathode degradation was the dominant contribution to degradation at higher current densities and lower temperatures. The anode was found to contribute more to degradation at higher temperatures. Generally, the degradation rates obtained were lower at higher operating temperatures, even at higher current densities. A degradation rate as low as 2%/1000 h was observed at 1.7 A/cm 2 and 950°C over an operating period of 1500 h.

Solid Oxide Electrolysis Cells: Microstructure and Degradation of the Ni/Yttria-Stabilized Zirconia Electrode

“…34 Microstructure vs loss in performance for long-term tested SOECs.-Due to the results from EIS during electrolysis testing a more detailed quantitative analysis of possible microstructural changes of the Ni/YSZ electrode was performed, i.e., Ni particle size distributions for the active electrode layer of reference and tested cells was determined. The method for obtaining Ni particle size distributions was adapted from the work by Hagen et al 21 The size distributions of Ni particles were therefore obtained by superimposing a set of parallel lines with a pitch of 1 m on the innermost 10 m of the Ni/YSZ electrode closest to the electrolytes. The chord lengths within Ni particles were measured.…”

Influence of temperature and atmosphere on the strength and elastic modulus of solid oxide fuel cell anode supports

“…Ref. [25]. The composition of the NiO-YSZ anode support was 55 wt% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 6 NiO with 45wt% YSZ.…”

Assessment of the Cathode Contribution to the Degradation of Anode-Supported Solid Oxide Fuel Cells

“…1 Cathode degradation was identified to be the dominant contribution to degradation at low temperatures and high current densities. 1 A significant difference in cathode degradation has been reported for cells when tested at 750°C in oxygen or in air.…”