Morphology and electrochemical characterization of LaSrCuO4 − δ|Ce0.9Gd0.1O2 − δ interface

The electrochemical properties of LaSrCuO4 − δ (LSCO) electrode screen-printed on Ce0.9Gd0.1O2 − δ (CGO) electrolyte have been investigated. The morphology of the LSCO|CGO interface was analyzed by scanning electron microscopy. The LSCO|CGO|LSCO symmetric cells with porous electrodes were studied by both AC impedance spectroscopy at OCV conditions and cyclic voltamperometry (CVA) in the temperature range of 500–900 °C at the oxygen partial pressures of 10− 4–0.21 atm. The impedance response consisted of two depressed semicircular arcs which indicated that the overall electrode process included at least two distinguishable rate-determining steps of oxygen exchange process. It was found that the rate-determined steps of the overall electrode process changed at temperature around 700 °C. The area specific resistance (ASR) at the temperatures of 750–900 °C in air decreased in the range from 10 Ω cm2 to 1 Ω cm2. The ASR of the electrode cycled in the range of 500–900 °C for 5 days was stable for a long time under heat treatment that proved the electrochemical stability of the interface.

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► The electrochemical behaviour of LaSrCuO4-δ|Ce0.9Gd0.1O2-δ interface was investigated.
► The rate-determining steps of oxygen exchange process were determined.
► LaSrCuO4-δ exhibited stability of the electrode properties for a long time under thermal cycling.