Jiqin Qian

Multilayer tape-casting method for anode-supported planar SOFCs

We have developed a multilayer tape-casting and co-sintering process to fabricate a large-area, anode-supported electrolyte film, which is critical for planar-type, reduced-temperature solid oxide fuel cells (SOFCs). Nickel/yttria-stabilized zirconia (Ni/YSZ), nickel/scandia-stabilized zirconia (Ni/ScSZ) cermets, ScSZ, Ce 0.8 Gd 0.2 O 1.9 (CGO), and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3δ (LSCF)–CGO were used as materials for anode substrate, anode functional layer, electrolyte, interlayer and cathode, respectively. The powders of these functional layers were ball-milled with organic additives to form slurries, which were assembled together with the multilayer tape-casting procedure to get the green tapes. After drying, the green tape was co-sintered at 1400°C for 4 h in air to get the large-area, anode-supported electrolyte film (thickness 15 μm). For cell preparation, the LSCF–CGO composite cathode was deposited by the screen-printing method and sintered at 1100°C for 3 h. The area-specific resistance (ASR) of the obtained single cell was found to be 0.99 ωcm 2 at 850°C with H 2 /O 2 as the operating gases, and the maximum power density achieved was 0.63 W/cm 2 . The thickness of the (Zr,Ce)O 2 -based solid solution formed at the ScSZ/CGO interface during high-temperature sintering was investigated. The results illustrate that fabrication of an anode-supported electrolyte film for planar SOFCs with a CGO interlayer is possible by the multilayer tape-casting procedure, which is both cost-effective and feasible.

La0·8Sr0·2Cr0·5Fe0·5O3-d as anode material on cathode-support SOFCs for direct hydrocarbon utilisation

Abstract Perovskite oxides have some advantages compared with metal oxides when used for hydrocarbon fuel. La0·8Sr0·2Cr0·5Fe0·5O3-d (LSCF) was prepared by the sol–gel method. X-ray diffraction shows that pure perovskite phases of LSCF were obtained at 1100°C. Catalytic properties and conductivity were investigated by temperature-programmed reduction and the four-probe method. Finally, utilising tape casting and lamination, we fabricated a cathode-support SOFC with a LSCF-Zr0·89Sc0·1Ce0·01O2-x(SSZ) anode by a one-time co-sintering process at 1250°C. The performance of the functioning fuel cell and a short-term stability test were investigated both in H2 and CH4 fuels. The result show that LSCF is a possible electrode material for future applications.