Characterisation of composite SOFC cathodes using electrochemical impedance spectroscopy. Analysis of Pt/YSZ and LSM/YSZ electrodes
2002; Elsevier BV; Volume: 47; Issue: 13-14 Linguagem: Inglês
10.1016/s0013-4686(02)00095-6
ISSN1873-3859
AutoresAntonio Barbucci, R. Bozzo, G. Cerisola, Paola Costamagna,
Tópico(s)Gas Sensing Nanomaterials and Sensors
ResumoThe performance of composite electrodes as a function of the electrode composition is investigated experimentally through electrochemical impedance spectroscopy (EIS). In particular, two different composite cathodes are analysed, i.e. Pt/YSZ and LSM/YSZ. Typical impedance spectra have been obtained and used to evaluate the overall electrode polarisation resistance Rp. The qualitative features are similar for both cathodes; in particular, in both cases the electrode performance (expressed in terms of Rp−1) shows a dome-shaped curve as a function of the electrode composition. Nevertheless, the quantitative aspects are very different; in particular, the maximum value of Rp−1 is much higher for the LSM/YSZ electrode than for the Pt/YSZ one (22 vs. 1.5 S cm−2). Also, the composition which gives the maximum performance and the experimental values of the percolation thresholds are different. The reasons for the discrepancies are analysed and discussed.
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