SINGLE CELL TESTING AND PERFORMANCE ANALYSIS OF PLANAR SOLID OXIDE FUEL CELLS

SOFCo-EFS Holdings LLC is developing planar solid oxide fuel cells (SOFC) for a range of mobile and stationary power systems ([1]). A reliable, reproducible single cell test capability has been essential in facilitating continued progress in the development of our SOFC technology. This paper describes the design of SOFCo-EFS' single cell test stands and discusses testing procedures used to characterize the performance of cells. These tests are employed for standard performance criteria measurements and to evaluate/qualify cells for stack tests. The high reliance on single cell qualification testing at representative operating conditions (e.g., high fuel utilization) prior to transitioning next generation cells to stack testing has led SOFCo-EFS to carefully examine the results generated by the single cell tests. In addition, specially instrumented single cell tests have been used to diagnosis the causes of cell performance degradation over various testing conditions. An overview of the custom designed test stands and their sub-components are described. The test stands allow for easy modification in order to accommodate custom testing procedures. The sealess design leads to easy, fast test setup, and yields reliable and reproducible testing results. Standard test outputs include voltage-current (VI) and power curves, Area Specific Resistance (ASR) calculations, ASR and power degradation and fuel utilization. Special tests that employ multiple voltage taps allow the measurement of current density changes across the cell surface with time and fuel utilization.