This paper shows that storage at room temperature and ambient atmosphere appears to affect the polarisation resistance significantly and R-P decreased initially with storage time. This improvement was more pronounced when stored in moisturised air. The performance was, however, also found to decrease when stored for sufficiently long periods. The absolute values of the electrode response of these materials are very difficult to reproduce and the performance appears to be largely dependent on the manufacturing process of the powder or the electrode itself. In spite of this, the electrode behaviours exhibited similar patterns with respect to the dependence on T and Po-2. An increase in polarisation resistance with time at SOFC operating conditions was observed. which was related exclusively to the electrode reaction kinetics and not to oxygen concentration polarisation. It was also found to be higher when measured in moisturised air. (C) 2009 Elsevier B.V. All rights reserved.