Lower down both ohmic and cathode polarization resistances of solid oxide fuel cell via hydrothermal modified gadolinia doped ceria barrier layer

摘要

Hydrothermal reaction in Cerium and Gadolinium solution as an optimization method is developed and first reported for the densification of gadolinia doped ceria, the barrier layer between Zirconia electrolyte and (La,Sr) (Co,Fe)O3-delta cathode. This method is based on the hydrothermal reaction for nano particles in-situly grown on porous surface, to improve barrier layer density, alongside the sintering of cathode at 1075 degrees C. As a result, the ohmic resistance is prominently decreased by -16.4 % at 750 degrees C for electrolyte supported symmetrical cell. Whereas, the cathode polarization resistance is decreased by as much as a factor of -3 from 0.3702 omega center dot cm2 to 0.1325 omega center dot cm2 at 750 degrees C and pO2 = 0.21 atm. Furthermore, the anode supported cell exhibits higher open circuit voltage, smaller area specific resistance, elevated performance output and less degradation. And this modified barrier layer shows reduced Sr migration in 300 h operation at 750 degrees C. The hydrothermal reaction is demonstrated to prepare denser and sintering-active barrier layer with faster oxygen ion transfer and better interface connection, with large-scale application prospects and cost-competitiveness.