Journal of Power Sources, Vol.196, No.9, 4396-4403, 2011
Electrochemical characterisation of solid oxide cell electrodes for hydrogen production
Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H-2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV) in a one-atmosphere set-up. For the oxygen electrode, nano-structured La0.75Sr0.25MnO3 (LSM25) is impregnated into a LSM25/yttria stabilised zirconia (YSZ) composite, whereas for the steam electrode, nano-structured Ni and Ce0.8Gd0.2O2-delta (CGO) is impregnated into a Sr0.94Ti0.9Nb0.10O3-delta (STN) backbone. In the present study, the best performing oxygen electrode is a LSM25-YSZ composite with 20% porosity and impregnated with a LSM25 solution measuring a polarisation resistance (R-p) of 0.12 Omega cm(2) at 850 degrees C in oxygen. For the steam electrode, the best performance is obtained for a STN backbone, sintered at 1200 C and impregnated with CGO/Ni, with an R-p of 0.08 cm(2) at 850 degrees C in 3% H2O/H-2. (C) 2010 Elsevier B.V. All rights reserved.