Solid Oxide Fuel Cell Cathode Enhancement Through a Vacuum-Assisted Infiltration Technique

Solid Oxide Fuel Cell (SOFC) technology promises to provide an efficient method by which electricity can be generated from coal-derived syngas, biofuels, and natural gas, while increasing energy security and reducing greenhouse gas emissions. The large capital costs attributed to the cathode low performance and long-term stability issues are a current limitation of SOFC technologies that must be addressed before commercial SOFC power generation can be realized. The typical SOFC composite cathode, consisting of an electrolyte material and an ABO3-type perovskite oxide, possesses excellent performance characteristics but is subject to chemical stability issues during manufacturing and power generation operation at elevated temperatures. The proposed work aims to develop a vacuum-assisted infiltration technique to improve SOFC cathode performance and longevity through the impregnation of an inexpensive electrocatalyst precursor into a cathode backbone. Upon calcination at reduced temperatures, a thin but continuous network of nano-sized catalysts is formed and covered the cathode backbone with enlarged catalytic surface area and heterogeneous microstructure, thus enhancing both the oxygen exchange rate and oxygen ions transport rate on the cathode surface. Cathode stability will be greatly improved through the use of the reduced temperature calcination. In Phase I, the vacuum-assisted infiltration apparatus and the infiltration protocol will be developed and validated in both button cells and short stacks having 100 cm2 per-cell active areas. Catalyst distribution and morphology will be investigated via advanced X-ray diffraction and radiographic techniques. Phase II will support manufacturing scale-up to meet SECA cost goals, and will include kW-scale stack validation.Commercial Applications and Other Benefits: Commercial applications include: (a) MW scale central power generation; (b) distributed power generation; (c) uninterrupted power backup units; and (d) portable power supplies for both residential and military applications. Some noteworthy benefits of the proposed technology are: (1) the technique readily scale to implementation in mass production operations; (2) enables SOFC technology fast market adoption and penetration via capital cost reduction; (3) reduces the green-house-gas emission and (4) US dependence on foreign energy imports through the large scale implementation of the improved SOFC technology.