Electrochemical Performance and Time Stability of the Solid Oxide Cells with a (La,Sr)(Ga,Fe,Mg)O3−δ Electrolyte and (La,Sr)(Fe,Ga,Mg)O3−δ Electrodes

Electrochemical devices on solid electrolytes are closely considered from the point of view of efficient utilization of environmental resources in order to obtain a variety of products, including those with high added cost. This study provides insight into the functionality of electrochemical cells that have been designed with a specific configuration. These cells have the same ionic composition of the anode, cathode, and electrolyte. This was achieved by iron doping of highly conductive (La,Sr)(Ga,Mg)O_3-δ electrolyte, and gallium and magnesium doping of the electrode material based on (La,Sr)FeO_3-δ. The main focus in this study is on the electrochemical behavior of such cells depending on the oxygen partial pressure in the gas phase, as well as the stability of the electrochemical performance over time for more than 950 h of testing. According to the obtained results, the electrochemical cell with a completely identical ionic composition of electrodes La_0.6Sr_0.4Fe_0.85Ga_0.1Mg_0.05O_3-δ and electrolyte (La_0.8Sr_0.2)_0.98Ga_0.7Fe_0.1Mg_0.2O_3-δ demonstrated the best set of optimal performances. This consists of excellent chemical compatibility, high electrochemical activity (0.08 Ω cm² in air at 800 °C), and a minor degradation rate.