Improved performance of solid oxide fuel cell with pulsed laser deposited thin film ceria-zirconia bilayer electrolytes on modified anode substrate

摘要

Bilayer electrolytes composed of an yttria stabilized zirconia (YSZ) layer (～2 μm) and a samaria doped ceria (SDC) layer (～6 μm) have been successfully fabricated by pulsed laser deposition (PLD) technique at 600℃ for thin film solid oxide fuel cells (SOFCs). A NiO-YSZ (60:40wt.% with 10wt.% starch) anode supported YSZ/SDC bilayer electrolytes cell with Sm_(0.5)Sr_(0.5)CoO_(3-δ)-Ce_(0.8)Sm_(0.2)O_(2-δ) (SSC-SDC, 70:30 wt.%) cathode was tested, yielding open circuit voltage (OCV) value of 0.843 V and maximum power density of 0.87W cm~(-2) at 700℃. With a NiO-YSZ anode functional layer (50:50wt.%) introduced into anode/electrolyte interface, significantly enhanced cell performance was achieved, i.e., the cell OCV of 0.959 V and 0.98 V with maximum power density of 1.19 W cm~(-2) and 1.08 W cm~(-2) at 750℃ and 700℃, respectively. The electrical current leakage in the SDC single layer cell caused by the reduction of Ce~(4+) to Ce~(3+) in reducing environment has been eliminated by depositing the YSZ thin film as a blocking layer. Characterization analysis of the cell showed that the bilayer electrolyte deposited by PLD technique have retained the chemical, mechanical and structural integrity of the cell.