Fabrication and Performance of SOFC Electrode Nanoparticles and Nanostructures

Current solid oxide fuel cell (SOFC) electrodes are fabricated using traditional ceramic processing techniques of powder mixing and high temperature sintering. While high temperature sintering is required to form dense ceramic electrolytes and strong supporting structures, this leads to low surface area electrodes and limits our ability to control electrode structure. As we seek to increase the performance of multi-phase SOFC electrodes at intermediate temperatures, it will become increasingly important to enhance surface area and control electrode structure from the nano- to macro-scale.

We have utilized soft-chemistry approaches to create oxide electrocatalyst nanoparticle and inverse-opal electrode structures. SOFC cathode material nanoparticles were prepared using both inverse-micelle (IM) and co-precipitation approaches. The IM approach provides tight control over nanoparticle size. These solution-based approaches allow the upper calcination temperature to be limited, minimizing particle growth while still forming the desired oxide phase. Inverse opal structures were formed by templating with self-assembled polymer nanospheres. The resulting particles and structures were characterized in terms of structure, surface kinetics and electrochemical performance in a working SOFC electrode.