Study on the performance of GDC electrolytes fabricated by atmospheric plasma spraying and vacuum plasma spraying

Abstract

For metal-supported solid oxide fuel cells (MS-SOFCs), gadolinium-doped ceria (GDC) is one of the most promising electrolyte materials due to its high ionic conductivity. The plasma spraying technique has unique advantages in the preparation of MS-SOFCs, such as high efficiency, low cost, and low thermal impact on the metal support. However, few studies have been conducted on the preparation of dense GDC electrolytes using plasma spraying technology. In addition, it is not clear whether the composition and Ce valence state of GDC change during the plasma spraying process. In order to investigate this issue, GDC electrolytes were fabricated by atmospheric plasma spraying (APS) and vacuum plasma spraying (VPS) techniques. It is found that the GDC electrolyte fabricated by VPS is denser and has better electrochemical performance. The open circuit voltage and maximum power density of the VPS-cell at 600 °C are 0.90 V and 175.7 mW/cm2, respectively, while those of the APS-cell are 0.86 V and 124.8 mW/cm2, respectively. Moreover, the valence state of Ce4+ in the GDC electrolyte remains unchanged after plasma spraying, while the composition of Ce/Gd changes. This work successfully fabricates GDC electrolytes with qualified performance and provides a reference for further optimizing spraying parameters to prepare high-performance MS-SOFC.