Ni modified ceramic anodes for solid oxide fuel cells

Ni modified Sr2Fe1.5Mo0.5O6 (SFM) and La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) anodes have been studied as anode materials for solid oxide fuel cells (SOFCs). Temperature-programmed reduction (TPR) results show that Ni promotes the oxidation of H2 on SFM. As a result, a cell with Ni-SFM as the anode, La0.8Sr0.2Ga0.83Mg0.17O3 (LSGM) as the electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) as the cathode shows a high peak power density of 1166 mW cm−2 at 800 °C using H2 as the fuel and ambient air as the oxidant. Ni modified SFM also shows enhanced performance in CH4 (with 3 vol% H2O). Compared with SFM, Ni-SFM anode demonstrates enhanced catalytic activity, resulting in higher open-circuit voltage and lower electrode polarization resistance in CH4. However, due to the presence of Ni, the sulfur tolerance of these Ni-modified anodes is still low. The cell performance drops by almost 18% after the cell with Ni-SFM anode has been operating for 20 h in a fuel of H2 with 100 ppm H2S at 800 °C. However, the cell performance can be fully recoverable upon removal of H2S from the fuel stream. Similar cell performance improvements have also been observed on cells with Ni modified LSCM anodes. The cells with the Ni-LSCM anodes have shown relatively stable performance during the short-term durability test at 800 °C in CH4 at 800 °C.

► 2 wt% Ni has been dispersed on ceramic anodes to improve the cell performance.
► The catalytic activity of the ceramic anode has been significantly improved with Ni.
► Degradation of the Ni-modified ceramic anode in H2S-containing fuel can be fully recovered.
► Relatively stable cell performance has been observed when operating in CH4.