Manufacturing ScCeSZ/GDC Electrolyte Composite Layers for IT-SOFC by Reverse Aqueous Tape Casting

Recent advances in solid oxide cell (SOC) technology have been focusing on the materials so they to increase the power capability at reduced operating temperatures, from now typically around 800ºC to below 700ºC. In light of this, this work investigates the potential of a NiO/10Sc1CeSZ anode, and 10Sc1CeSZ electrolyte, with an La0.6Sr0.4Co0.2Fe0.8 Oxide (LSCF) cathode and Gd0.2Ce0.8 Oxide (GDC) barrier layer. It has previously been difficult to manufacture these cells via tape casting because the GDC barrier layer delaminates from the electrolyte layer upon high temperature sintering. This is due to thermal expansion coefficient (TEC) mismatch. Here, the capability of using reverse aqueous tape casting to manufacture anode supported cells (ASC) using a multi-layer technique is proven. GDC barrier layer, new electrolyte/barrier layer, electrolyte layer, anode functional layer (AFL) and anode substrate (AS) are tape cast effectively. The composite layer allows for a gradual transition from electrolyte to barrier layer eliminating the harsh step-change of TEC and, therefore, delamination upon sintering. Multiple cells were tested between 650 and 800ºC in a hydrogen/nitrogen mixture on the anode and air on the cathode side to yield a maximum power density of 0.4 W/cm².