Reversible aging behavior of La0.8Sr0.2MnO3 electrodes at open circuit

► Aging behavior of LSM changes between 700 °C and 800 °C. ► Aging behavior is a mixture of reversible and irreversible changes in impedance. ► Reversible changes explained by reverse in cathode cation segregation behavior. ► Irreversible changes explained by microstructural changes of porous cathode.