Tape Casting of High-Performance Low-Temperature Solid Oxide Cells with Thin La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ Electrolytes and Impregnated Nano Anodes

Low-temperature solid oxide cells (LT-SOCs), operating at 400 to 650 °C, have great potential for commercialization since they can provide lower cost and improved long-term durability. Low operating temperature can also enable high round-trip efficiency of SOCs as reversible energy storage devices. This paper describes Sr_0.8La_0.2TiO_3-α (SLT) anode supported LT-SOC with thin La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ (LSGM) electrolyte made by tape casting, with screen printed La_0.6Sr_0.4Fe_0.8Co_0.2O_3-δ (LSCF) cathode and impregnated Ni anode. Optimization of the anode functional layers is described; the best anodes had 68 vol % LSGM and 12.3 vol % Ni and yielded maximum power density of 1.6 Wcm^-2 with a cell area specific resistance (ASR) of 0.21 ωcm² at 650 °C. Most of the cell ASR was associated with the cathode. Reversible electrolysis and fuel cell operation yielded similar characteristics with both 50% H₂-50% H₂O and syngas fuel. Life testing over 500 h showed that the cathode impedance stabilized after an initial break-in period; the ohmic and anode resistances, though relatively small, increased slightly with time.