The performance of current solid oxide fuel cells (SOFCs) was evaluated in terms of the cell designs and the physicochemical properties of the component materials such as the electrode and electrolyte in order to demonstrate the potentials of state-of-the-art SOFC technology for the widespread use of SOFCs. A flat tubular type SOFC stack for residential use was analyzed as a standard case of a production version in terms of stack volume, weight, and material cost. The power density and power generation efficiency were also evaluated by model estimation. A microtubular type SOFC was evaluated as an example of an advanced cell design. The assessment of the cell design can pinpoint performance advantages of the microtubular type in stack volume, weight, material cost, volumetric power density, and efficiency. In addition, we attempted to demonstrate an analysis for the concurrent comparison of the impact of cell designs and material properties on cell performance by using volumetric power density as a common assessment criterion. Through the assessment with the state-of-the-art SOFC technology, it is possible to make a quantitative comparison of the significances of cell design and material property. The present assessment suggests that the development of cell design is a consistent approach to improving cell and stack performance. In this way, the proposed assessment can provide hints to a reliable research strategy for improving cell performance and realizing the widespread use of SOFCs.
Future prospects for the design of ‘state-of-the-art’ solid oxide fuel cells
