Enhanced performance of solid oxide fuel cells using highly conductive Ca 2+and F- co-doped Gd 0.2 Ce 0.8 O 1.9 buffer layer

Gadolinium -doped ceria (GDC) is the most widely used buffer layer to prevent the reaction between YSZ electrolyte and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3- delta (LSCF) cathode for commercial solid oxide fuel cell (SOFC). However, conductivity and sintering activity are vital to cell performance. In this paper, Ca 2+ and F - co -doped GDC (Ca 0.03 Gd 0.17 Ce 0.8 F 0.06 O 1.84- delta , CGDCF) is used as a buffer layer to improve the performance and stability of SOFC. The co -doped F - and Ca 2+ significantly improve the sintering properties and oxygen ion transport of traditional GDC material. Meanwhile, the optimized sintering temperature is 1300 degrees C, with the lowest ohmic resistance. The peak power density of a cell with a CGDCF buffer layer reaches 1.809 W cm -2 at 850 degrees C, which is 37 % higher than that of GDC. In addition, the cell with the CGDCF buffer layer exhibits excellent stability during the 150 h test owing to the lower migration of La and Sr elements. Thus, the Ca 2+ and Fco -doped GDC oxide emerges as a promising material for buffer layer applications.