Zvezdkin M.A., Konopelko M.A., Zvezdkina I.V., Tolkacheva A.S., Yazev A.E., Pankratov A.A.
ABSTRACT
New material based on LaLi0.15Co0.125Fe0.725O3 was studied as potential cathode for molten carbonate fuel cells. The morphology of oxide powders synthesized by the solid-state reaction between oxides and carbonates as the initial components was found to have the form of smooth plates, which is not favorable for the formation of an effective porous structure of a gas diffusion electrode. It was shown that the powder’s morphology can be improved by one step mechanical treatment in a planetary mill. Powders with the required bimodal particle size distribution were obtained by a selected processing mode. The effect of the cathode powder treatment on the electrochemical activity of the porous gas diffusion electrode was studied. The effect of the anodic lyophilic additive Al2O3 on the current-voltage characteristics of fuel cells with a new cathode material was studied. The optimal filling of the cell with electrolyte for all combinations of cathode and anode materials were found to be located in a rather narrow range of 1.12–1.18. The specific power of the cell with the best performed LaLi0.15Co0.125Fe0.725O3 cathode was 154 mW/cm2 at the current density of 225 mA/cm2. This result is modest compared to the characteristics of the reference NiO cathode material, which has demonstrated 210 mW/cm2. Since the determined earlier exchange currents on dense immersed electrodes LaLi0.15Co0.125Fe0.725O3 were higher than on NiO, it was concluded that the morphology of new gas diffusion electrodes requires additional optimization.
KEY WORDS:
carbonate melt, fuel cell, perovskite, lanthanum ferrite, oxygen reduction, electrochemical activity, gas diffusion electrode
DOI: 10.31857/S0235010620060146