Application of Composite Technology for SOFCs

AbstractComposite technology is a new approach to solid oxide fuel cell (SOFC) fabrication. It is based on the net shape processing, which uses a combination of colloidal suspension and polymer precursor techniques. Different elements of SOFC can be prepared and optimized using this approach and the flexibility of the net shape processing. The goal of this research was to develop net shape procedures for different elements of SOFC, to show the real possibility preparing all these elements of SOFC and to investigate the advantages of composite technology. A nickel-YSZ composite was prepared and investigated as the prospective anode material. High electronic conductivity and stability in REDOX cycles were shown for this material. Different cathode compositions were prepared using composite technology and tested. It was shown, that these materials ensure low overpotentials and are time stable at operation temperature up to 800°C. All three SOFC designs were tested: anode, cathode and electrolyte supported SOFCs. It was possible to achieve low resistance of SOFC structure for all designs, but electrode supported SOFCs had limitation in the current connected with the gas diffusion through thick electrode substrates. The best performance was achieved on an electrolyte supported system with 100 [.proportional]m YSZ electrolyte and composite anode and cathode: 0.75W/cm2 power density at 0.6 V at 800°C.