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

Abstract

Bilayer electrolytes composed of an yttria stabilized zirconia (YSZ) layer (∼2μm) and a samaria doped ceria (SDC) layer (∼6μm) have been successfully fabricated by pulsed laser deposition (PLD) technique at 600°C for thin film solid oxide fuel cells (SOFCs). A NiO-YSZ (60:40wt.% with 10wt.% starch) anode supported YSZ/SDC bilayer electrolytes cell with Sm0.5Sr0.5CoO3−δ-Ce0.8Sm0.2O2−δ (SSC-SDC, 70:30wt.%) cathode was tested, yielding open circuit voltage (OCV) value of 0.843V and maximum power density of 0.87Wcm−2 at 700°C. 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 0.959V and 0.98V with maximum power density of 1.19Wcm−2 and 1.08Wcm−2 at 750°C and 700°C, respectively. The electrical current leakage in the SDC single layer cell caused by the reduction of Ce4+ to Ce3+ 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.