A symmetrical solid oxide fuel cell prepared by dry-pressing and impregnating methods

In this study, a simple and cost-effective dry-pressing method has been used to fabricate a symmetrical solid oxide fuel cell (SOFC) where the dense yttria-stabilized zirconia (YSZ) electrolyte film is sandwiched between two symmetrical porous YSZ layers in which La_0.75Sr_0.25Cr _0.5Mn_0.5O_3-δ (LSCM) based anode and cathode are incorporated using wet impregnation techniques. The maximum power densities (P_max) of a single cell with 32 wt.% LSCM impregnated YSZ anode and cathode reach 333 and 265 mW cm^-2 at 900 °C in dry H₂ and CH₄, respectively. The cell performance is further improved with additional impregnation of a small amount of Sm-doped CeO ₂ (SDC) or Ni. When 6 wt.% Ni as catalyst is added to both the anode and cathode, P_max values of 559 and 547 mW cm^-2 can be achieved, which are better than with SDC. The effect of Ni on the cathode performance is also investigated by impedance spectra analysis.