Increased Porosity in NiO-YSZ Tubular Substrate for High Performance Solid Oxide Electrolysis Cell Using LaGaO₃ Film

Solid oxide electrolysis cells (SOECs) are an important subject for storage of renewable energy such as solar or wind power. In this study, tubular type SOECs using La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 (LSGM) electrolyte film were prepared on NiO-Y 2 O 3 stabilized ZrO 2 (YSZ) with different porosity and it was found that the porosity of the Ni-YSZ tubular substrate is an important parameter for achieving initial high current density and also low rate of durability by preventing the pulse potential noise. The addition of cornstarch as pore-formers was effective for increasing channel size (3.9 μm of average radius) in Ni-YSZ substrate and when 15 wt% cornstarch was added for extruding NiO-YSZ substrate, the tubular cell exhibited the superior initial performance, 0.69 A cm −2 at 1.6 V in SOEC mode at 873 K. This cell also shows smaller degradation rate by suppression of the pulse potential noise and the high coulomb efficiency of H 2 formation. Increase in porosity of Ni-YSZ substrate is highly important for increasing the initial performance and long-term stability of SOEC.