Fabrication of nanoparticle networked La0.6Sr0.4Co0.2Fe0.8O3-δ thin film layer between the cathode and electrolyte of solid oxide fuel cell by using a spin coating method

Abstract

The main chemical reactions such as oxygen reduction and oxygen ion diffusion occur at cathode/electrolyte interface in solid oxide fuel cell (SOFC); therefore it is the major governing property of SOFC performance. The nanoparticle network of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) thin film layer was coated via spincoating using metal-nitrate solution on the electrolyte layer. This layer enhances the interconnect property between cathode layer and electrolyte by enlarge the connecting areal density between cathode and electrolyte. The layer was annealed at 500°C after spin-coating process. LSCF-gadolinium doped ceria (GDC) cathode layer was screen printed on the layer and sintered at 1050°C. The crystallite size and thickness of the LSCF layer were measured by scanning electron microscopy (SEM). The results were 20 to 50nm and 200 to 300nm, respectively. The I-V performance of the cell was improved when the layer was coated. Electrochemical impedance spectroscopy (EIS) data of the cells showed that ohmic resistance and cathode polarization were lower than the cell without thin film layer.