Preparation and Performance of Hierarchical Scaffold Cathode for Low-Temperature Solid Oxide Fuel Cells

In order to improve the electrochemical performance of cathodes for low-temperature solid oxide fuel cells, two kinds of La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ/Ce_0.9Gd_0.1O_2–δ (LSCF/GDC) cathodes with a multifunctional hierarchical scaffold structure were prepared. The microstructure and electrochemical properties of the cathodes were investigated. The results show that the GDC primary scaffold with a porosity of 80.5% fully ensure the construction of LSCF or GDC secondary scaffold, subsequent loading and oxygen diffusion in the working state. Based on the analyses of distribution of relaxation times for the electrochemical impedance spectra, the cathode with LSCF nanoparticles as a secondary scaffold has a total polarization resistance of only 0.236Ω·cm² at 600℃ due to the abundant reactive sites and unobstructed electronic conduction, and the GDC nanoparticles loading promotes the adsorption/dissociation of oxygen. The hierarchical scaffold cathode has a simple process and excellent oxygen reduction performance, which can promote the further development of low-temperature solid oxide fuel cells.