Experimental study on the performance of a flat-tube reversible solid oxide cell and multi-objective operation optimization

The reversible solid oxide cell (RSOC) has advantage of high efficiency, fuel flexibility, and potential for renewable energy storage and utilization. Flat-tube RSOC is widely researched since both good sealing performance and current density. In this study, a flat-tube RSOC was designed and tested under various operating parameters. The I-V characteristics, electrochemical impedance spectra (EIS), and corresponding distribution of relaxation times (DRT) analyses were combined to investigate the influencing characteristics and mechanisms of different operation parameters. The high temperature reduced ion and charge-transfer resistances, and the hydrogen partial pressure dominated the mass transport, the mass flow rate and back pressure has less effect on the RSOC performance. Finally, RSOC cell operation performance was optimized with multi-objective optimization method and the combination of optimal operating parameters was obtained. A fuel utilization of 0.8735, an oxygen utilization of 0.405, and a net power output of 3 W can be obtained in the three-objective optimization.