High-performance, stable buffer-layer-free La0.9Sr0.1Ga0.8Mg0.2O3 electrolyte-supported solid oxide cell with a nanostructured nickel-based hydrogen electrode

La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) with an extraordinary oxygen-ion conductivity has been extensively studied as an electrolyte material for intermediate temperature solid oxide cells (SOCs). However, the conventional hightemperature sintering process of electrodes results in detrimental reaction between LSGM and Ni-based hydrogen electrode and microstructural coarsening of the electrode. Herein, a buffer-layer-free LSGM electrolyte-supported single cell with a nanostructured Ni-Gd0.1Ce0.9O1.95 (GDC) electrode is developed using a sintering-free fabrication approach. The cell exhibits a peak power density of 1.23 W cm-2 at 800 degrees C and an electrolysis current density of 1.85 A cm-2 at 1.5 V with excellent operating stability. The good performance and durability is owing to the synergistic effects of the elimination of elemental interdiffusion at the electrode/ electrolyte interface, polarization induced in situ formation of hetero-interfaces between Ni-GDC and LSGM, and remarkable structural stability of Ni-GDC. This study provides an innovative means for the development of efficient and durable buffer-layer-free LSGM-supported SOCs.