Reduction in ohmic contact resistance at interface between Gd-doped CeO2 interlayer and Sc2O3-stabilized ZrO2 electrolyte in SOFCs to improve performance

•Ohmic contact resistance between GDC and ScSZ of SOFCs was investigated.•The use of GDC interlayer led to an increase in the ohmic resistance of SOFCs.•Optimum sintering temperature of GDC interlayer was 1300 °C.•Addition of 0.3 mol% Mn to GDC improved contact condition between GDC and ScSZ.•An anode-supported cell with an optimized interlayer achieved 1.5 W cm− 2 at 800 °C.

Influence of the ohmic contact resistance at the interface between Gd-doped CeO2 (GDC) interlayer and scandia-stabilized zirconia (ScSZ) electrolyte on the performance of solid oxide fuel cells (SOFCs) was investigated. When GDC interlayer was used, the ohmic resistance of SOFCs was increased due to insufficient contact conditions between the GDC interlayer and ScSZ electrolyte. To improve the contact conditions, the effect of sintering temperature and sintering aids (Mn, Fe, Bi) on the ohmic contact resistance was evaluated. As a result, using an optimized Mn-modified GDC interlayer (with added 0.3 mol% Mn and sintered at 1300 °C) to decrease the ohmic contact resistance, an anode-supported cell with Sr-doped LaFeO3 cathode and ScSZ electrolyte achieved a power density of 1.5 W cm− 2 at 800 °C.