Solution infiltrated lanthanum nickelate–GDC composite cathode via flash-light sintering for intermediate temperature solid oxide fuel cells

초록

Solid oxide fuel cells (SOFCs) require high operating temperatures to minimize the oxygen reduction reaction resistance at cathode and increase the ionic conductivity of oxygen. However, at high operating temperatures, their stability during long-term operation degrades because of material deterioration and the mutual chemical reactions occurring at the interfaces. Herein, an electrode–electrolyte composite is fabricated by solution infiltration of lanthanum nickelate (LNO) electrode material into a GDC electrolyte layer to ensure more reaction sites compared with the conventional powder mixing of the electrode and electrolyte material. Further, the conventional thermal sintering process is replaced with the flash-light sintering process. Thus, the performance of the LNO–GDC cathode cell manufactured by flash-light sintering improves owing to suppression of grain growth of the infiltrated LNO particles. The microstructures of the infiltrated solution and composite layer of the electrolyte material are analyzed using field-emission scanning electron microscopy, and the crystallinity of the LNO nanoparticles is analyzed using high-resolution transmission electron microscopy. A maximum power density of 1.1 W/cm2 is achieved, an improvement of 58 % over the LSCF cell without infiltration at 750 ℃. This study is expected to contribute to the commercialization of SOFCs by replacing conventional thermal sintering.

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