Effects of Nanoscale PEALD YSZ Interlayer for AAO Based Thin Film Solid Oxide Fuel Cells
Gu Young Cho, Wonjong Yu, Yoon Ho Lee, Yeageun Lee, Waqas Hassan Tanveer, Yusung Kim, Sanghoon Lee, Suk Won Cha#
Performance of thin film solid oxide fuel cells (TF-SOFCs) were improved by inserting plasma enhanced atomic layer deposition (PEALD) of yttira-stabilized zirconia (YSZ) interlayers. By controlling the ratio between Y2O3 and ZrO2 in YSZ deposition supercycles, Y2O3 mol.% in YSZ films were changed. High Y2O3 contained PEALD YSZ interlayered cell showed higher maximum power density (123.6mW/cm2 at 500°C, 286.1mW/cm2 at 550°C) and smaller polarization resistance compared with reference Y2O3 concentrated PEALD YSZ interlayer cell. (108.5mW/cm2 at 500°C, 181.1mW/cm2 at 550°C) Exchange current densities of TF-SOFCs at 500°C also improved ~ 59.3% at high Y2O3 concentrated PEALD YSZ interlayer cells. These phenomena caused by high density of oxygen vacancies in high Y2O3 concentrated PEALD YSZ interlayer, which helps oxygen incorporation reactions at cathode-interlayer interface. Therefore, cathodic polarization loss related with oxygen reduction reactions was decreased, and then, performance and exchange current density were improved. Results of this study imply that insertion of simple PEALD YSZ interlayer at cathode-electrolyte interface efficiently improves performance and electrochemical characteristics of TF-SOFCs.