Influence of nano-sized LSCF cathode and its firing temperature on electrochemical performance in oxygen-excess-type solid electrolyte (OESE)-based fuel cells

Abstract

Dense films of an oxygen-excess-type solid electrolyte (OESE) based on Mg-doped lanthanum silicate (MDLS) were fabricated and applied to electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). To obtain dense MDLS films on NiO-MDLS porous substrates, a conventional spin-coating technique using the MDLS printable paste, obtained by mixing nano-sized MDLS particles and a dispersant, was employed. The Ni-MDLS anode supported single cells were then fabricated by printing porous cathode layer onto the electrolyte film surface. By optimizing fabrication conditions of an MDLS film and cathode, the highly active cathode/OESE interface (ASR = 0.23  cm 2 at 873 K) were successfully obtained, which resulted in high power density of 0.166 W cm -2 at 873 K in the fuel cell test when operated with argon-diluted hydrogen and pure oxygen as the fuel and the cathode gas, respectively.

A perspective on low-temperature solid oxide fuel cells

“…The apatitestructure material lanthanum silicate La good conductivity that can be improved by adding dopants such as Al and Mg, 65,66 and successful SOFCs have been produced although the maximum power density was relatively low, 0.166 W cm À2 at 600 1C. 67 Germanium-containing analogs, La 10Ày Ge 6 O 26AEd were also investigated. 68 La 2 Mo 2 O 9 also provides good conductivity, but its incompatibility with electrode materials and its stability under redox cycling, are serious concerns.…”

Effects of La content on the densification, microstructure, and conductivity of doped La10−xGe6O26±δ electrolytes

“…Apatite‐type materials (A 10− x M 6 O 26±δ ; A = rare earth or alkaline earth and M = Si and Ge) are considered potential candidates for electrolytes in SOFCs, in addition to common oxide ion conductors, including fluorite‐structured Zr 0.84 Y 0.16 O 1.92 (YSZ) and Sm 0.2 Ce 0.8 O 2−δ (SDC), and perovskite‐structured La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3 (LSGM) . The hexagonal structure is composed of isolated MO 4 tetrahedra aligned to form two distinct channels.…”