YBaCuO-type perovskites as potential air electrodes for SOFCs. The case of YSr2Cu2FeO7+δ†
Abstract
The electrochemical properties of YSr2Cu2FeO7+δ with YBaCuO-type structure have been studied. The temperature dependent oxygen content of this oxide has a marked influence on its p-type conducting behavior, since topochemical oxygen release occurs on heating above 673 K while reversible oxygen uptake takes place on cooling. Mixed valence Fe3+/Fe4+ and Cu2+/Cu3+ in combination with anion vacancies within the oxygen-sublattice suggest mixed (electronic and ionic) conductivity in this oxide. Electrochemical measurements indicate that YSr2Cu2FeO7+δ shows high oxygen reduction reaction activity at intermediate temperatures, revealing its potential applications as an air electrode in SOFCs.