Sequential Tape Casting of Anode-Supported Solid Oxide Fuel Cells

A novel route was developed to fabricate anode-supported solid oxide fuel cells with a high throughput and low manufacturing costs. In contrast to classical manufacturing routes, this novel route starts with the tape casting of the thin electrolyte followed by the tape casting of the anode and anode support. All three layers were cast green-on-green and finally sintered to yield a gas-tight electrolyte. By carefully selecting the raw materials for all three layers, it is possible to manufacture near-net-shape half-cells. The half-cells were characterized with respect to thickness, microstructure, bending behavior, electrolyte gas leakage, shrinkage, electrolyte residual stresses, and mechanical strength. Finally, the cathode was screen-printed and fired, and the full cell characteristics were obtained in single-cell and stack tests. Additionally, a scale-up to cell sizes of 200x200mm(2) was verified. Electrolyte and anode thickness were around 20m, and the support was cast to 300-500m. The helium leak rates were better than the necessary internal threshold, and the characteristic bending strength obtained was in the range of 150-200MPa. The single-cell tests revealed current densities of 1.0Acm(-2) at 700mV and 800 degrees C (H-2/air). A first stack test proved their stackability and operational functionality.