Mechanism for Major Improvement in SOFC Electrolyte Conductivity When Using Lithium Compounds as Anode

High Resolution Image Download MS PowerPoint Slide Recent studies indicate that the electrolyte ionic conductivity in an SOFC can be considerably increased by using lithium compounds as the electrode. We found that the ionic conductivity of Gd 0.1 Ce 0.9 O 1.95 electrolyte in the Ni 0.8 Co 0.15 Al 0.05 LiO 2 anode cell was 10.1 mS/cm only at 550 °C without H 2, but it increased to 44.6 mS/cm after feeding H 2 to the anode. It was found that LiOH/Li 2 CO 3 moved into the GDC electrolyte from the NCAL anode and formed a three-phase composite electrolyte. A space charge region with a high oxygen vacancy concentration is formed around the interface of LiOH/Li 2 CO 3 and GDC, which increases the ionic conductivity.