INTERFACIAL STUDIES OF SOLID-STATE CELLS BASED ON ELECTROLYTES OF MIXED IONIC-ELECTRONIC CONDUCTORS

Combination of 4-probe impedance and polarization measurements offers an effective approach to investigate electrode kinetics and transport properties of each cell component in a solid-state electrochemical cel l based on an electrolyte of mixed ionic-electronic conductor (MIEC). In particular, two representative solid-state cells, one with an elect rolyte of an MIEC (Pt /BaCe0.8Gd0.2O3/ Pt) and the other with an elect rolyte of an ionic conductor (Pt /Bi1.5Y0.5O3/ Pt), are used as exampl es to demonstrate the uniqueness of these techniques in separating the response of each cell component, in measuring the interfacial polariz ation resistance and overpotential of each individual interface, in id entifying reaction mechanisms (the nature of rate-limiting steps), and in determining kinetic parameters. (C) 1998 Elsevier Science B.V. All rights reserved.