(Invited) Ruddlesden-Popper Oxides As Bi-Functional Oxygen Electrodes

Abstract

Incorporating more renewables into our energy mix is a major challenge that confronts our transition to a carbon free economy. Solid oxide electrochemical cells when operated alternately in fuel cell and electrolysis modes, enable the incorporation and integration of far greater amounts of solar and wind energy into our power grid. As islanded systems, they can also function as distributed generation systems thereby decreasing our reliance on the power grid. In this talk, we present a recent survey of results on rSOCs based on rare earth nickelate – rare-earth doped ceria composite oxygen electrodes that exhibit excellent cycling behavior when operated alternately in solid oxide fuel cell (SOFC) and solid oxide electrochemical cell (SOEC) modes of operation. The degradation in such cells is significantly mitigated by mode-switching operation when compared to operating in single mode operation in electrolysis mode. By comparing distributed relaxation times (DRT) analysis of impedance spectra obtained from single-mode (electrolysis) operated cells, and cells operated in switched-modes, we obtain clues into cell degradation mechanisms.