Nanocomposite-derived Ni/YSZ hydrogen electrode active layer for enhancing performance of solid oxide electrolysis cells

A Ni/YSZ (Yttria-stabilized zirconia; YSZ) hydrogen electrode active layer was employed to improve the performance of solid oxide electrolysis cells (SOECs). The active layer was derived from pre-fabricated NiO/YSZ nanocomposite particles grown by a co-precipitation method. The hydrogen electrode supported cells with and without the active layer were prepared to investigate the effect of the active layer on performance and durability. The cell with the active layer exhibited a high current density of 1.93 A·cm−2 at 750 °C and 1.3 V. The performance was approximately 1.5 times higher than that of the cell without the active layer. Electrochemical impedance spectroscopy (EIS) revealed that the higher performance can be attributed not only to a decrease in polarization resistance but also to a reduction in ohmic resistance. Furthermore, the cell with the active layer showed durability comparable to or higher than that of the cell without the active layer, despite being composed of submicron-sized fine grains and pores.