Low temperature solid oxide fuel cells with pulsed laser deposited bi-layer electrolyte

摘要

Solid oxide fuel cells (SOFC) using a pulsed laser deposited bi-layer electrolyte have been successfully fabricated and have shown very good performance at low operating temperatures. The cell reaches power densities of 0.5 W cm\u22122 at 550 \ub0C and 0.9 W cm\u22122 at 600 \ub0C, with open circuit voltage (OCV) values larger than 1.04 V. The bi-layer electrolyte contains a 6\u20137 \u3bcm thick samarium-doped ceria (SDC) layer deposited over a \u223c1 \u3bcm thick scandium-stabilized zirconia (ScSZ) layer. The electrical leaking between the anode and cathode through the SDC electrolyte, which due to the reduction of Ce4+ to Ce3+ in reducing environment when using a single layer SDC electrolyte, has been eliminated by adopting the bi-layer electrolyte concept. Both ScSZ and SDC layers in the bi-layer electrolyte prepared by the pulsed laser deposition (PLD) technique are the highly conductive cubic phases. Poor conductive (Zr, Ce)O2-based solid solutions or \u3b2-phase ScSZ were not found in the bi-layer electrolyte prepared by the PLD due to low processing temperatures of the technique. Excellent reliability and flexibility of the PLD technique makes it a very promising technique for the fabrication of thin electrolyte layer for SOFCs operating at reduced temperatures.