Performance Evolution of Niobium Doped Lanthanum Strontium Ferrate Perovskite Anode for Solid Oxide Fuel Cells

摘要

In this paper, evolutions of La_(0.8)Sr_(0.2)Fe_(0.9)Nb_(0.1)O_(3-δ) (LSFNb) anodes for solid oxide fuel cells (SOFCs) with different microstructures are investigated, which are prepared by adjusting the weight ratio of electrode powder/organic binder during the preparation of slurries. AC impedance spectra clearly reveals that LSFNb anode made from 7:4-slurry shows better microstructure and lower polarization resistance (R_P) compared with those of LSFNb anode made from 7:2.5-slurry. Better electrochemical performance is obtained on the single cells using 7:4-anode and cathode slurries with maximum power density (MPD) reaching 331.9 mW·cm~(-2) after discharged for 200 h fueled by H_2, compared with 285.8 mW·cm~(-2) of the cell made from 7:2.5-slurries. The two cells exhibit excellent stability with undetectable degenerations for over 200 h. These results demonstrate that LSFNb made from thin slurries possesses better electrochemical performance and can active continuously without significant agglomeration, making porous LSFNb a promising perovskite anode candidate for SOFCs.