Cathodic Polarization Measurements on La0.9Sr0.1MnO3 Electrode for Solid Oxide Fuel Cells

  • Lee, H.Y. (Department of Chemical Technology, College of Engineering Seoul National University) ;
  • Oh, S.M. (Department of Chemical Technology, College of Engineering Seoul National University)
  • Received : 1992.08.11
  • Accepted : 1992.11.09
  • Published : 1993.03.01

Abstract

Cathodic oxygen reduction kinetics on $La_{0.9}Sr_{0.1}MnO_3$ electrode have been examined at $700-900^{\circ}C$ under various oxygen partial pressures. AC impedance and current interruption techniques were employed for the determination of charge transfer resistances for electrochemical oxygen reduction. The $R_{ct}$ values obtained from two different methods were very close each other for $La_{0.9}Sr_{0.1}MnO_3$ electrode. Activation energy for the electrochemical oxygen reduction was found to be 174kJ/mol under atmospheric oxygen pressure. $R_{ct}$ measurements as a function of oxygen partial pressure indicate that the rate-determining step for the electrochemical oxygen reduction on $La_{0.9}Sr_{0.1}MnO_3$ electrode is the charge transfer process.

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Acknowledgement

Supported by : Ministry of Energy and Resources