Journal of Power Sources, Vol.216, 124-130, 2012
Highly durable anode supported solid oxide fuel cell with an infiltrated cathode
An anode supported solid oxide fuel cell with an La0.6Sr0.4Co1.05O3-delta (LSC) infiltrated-Ce0.9Gd0.1O1.95 (CGO) cathode that shows a stable performance has been developed. The cathode was prepared by screen printing a porous CGO backbone on top of a laminated and co-fired anode supported half cell, consisting of a Ni-yttria stabilized zirconia (YSZ) anode support, a Ni-scandia-doped yttria-stabilized zirconia (ScYSZ) anode, a ScYSZ electrolyte, and a CGO barrier layer. LSC was introduced into the CGO backbone by multiple infiltrations of an aqueous nitrate solution followed by firing. The cell was tested at 700 degrees C under a current density of 0.5 A cm(-2) for 1500 h using air as oxidant and humidified hydrogen as fuel. The electrochemical performance of the cell was analyzed by impedance spectroscopy and current-voltage relationships. No measurable degradation in the cell voltage or increase in the resistance from the recorded impedance was observed during long term testing. The power density reached 0.79 W cm(-2) at a cell voltage of 0.6 V at 750 degrees C. Post test analysis of the LSC infiltrated-CGO cathode by scanning electron microscopy revealed no significant micro-structural difference to that of a nominally identical untested counterpart. (C) 2012 Elsevier B.V. All rights reserved.
Keywords:Cathode;Infiltration;Solid oxide fuel cells;Mixed ionic and electronic conductor;Electrochemical impedance spectroscopy;Scanning electron microscopy