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 high-temperature 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 °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.