Effect of buffer layer on the performance of LSCF cathode formed on the scandium doped zirconia

초록

In order to apply LSCF as a cathode and ScSZ as an electrolyte, a gadolinium-doped ceria (GDC) buffer layer was inserted between the cathode and electrolyte. It was confirmed that the GDC buffer layer could prevent unfavorable solid-state reactions at the LSCF/ScSZ interfaces. The GDC buffer layer was deposited on the ScSZ electrolyte by sol-gel process and screen-printing. A LSCF cathode on the GDC buffer layer exhibited excellent electrocatalytic performance even at 650°C. Impedance spectra showed that the resistance of the cell with the screen-printed and subsequently heat-treated at 1000°C was much lower than that of the cell with sol-gel derived GDC layer. Impedance spectra and current-voltage characteristics were evaluated at 800, 750, 650°C and discussed in terms of buffer layer morphology and the film thickness.