LaNi_(0.6)Co_(0.4)_O_(3-δ) dip-coated on Fe-Cr mesh as a composite cathode contact material on intermediate solid oxide fuel cells

摘要

The feasibility of using Crofer22APU mesh dip coated with LaNi_(0.6)Co_(0.4)O_(3-δ) (LNC) ceramic paste as a uniform contact layer on a Crofer22APU channeled interconnect was studied. The control of LNC dip coating thickness on Fe-Cr mesh was carried out by Theological measurements of the suspension. SEM cross-section of formed composite contact material showed good adherence between ceramic and metallic components. The measured area specific resistance (ASR) value at 800 ℃ was 0.46 ± 0.01 mΩ cm~2, indicating low contact resistance itself. The long term stability of metallic/ceramic composite was also studied. The contact resistance, when composite contact material was adhered to channeled Crofer22APU interconnect, was 5.40 ± 0.01 mΩ cm~2, which is a suitable value for the performance of IT-SOFC stack. The stability of the system after treating at 800 ℃ for 1000 h was characterized using X-ray Micro-Diffraction (XRMD), Scanning Electron Microscope equipped with an Energy Dispersive X-ray analyzer (SEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) techniques. The oxidation rate of the alloy and Fe_3O_4 phase formation were enhanced on the channels of the interconnect. Thus, the formation of CrO_3 (g) and CrO_2(OH)_2 (g) species was accelerated on the composite surface under the channel. Through XRMD and XPS analysis the coexistence of two perovskite phases (initial LNC and Cr-perovskite) was observed.