The phase transformations, structural peculiarities, microstructure, and magnetoresistive properties of cathode materials based on lanthanum-strontium manganites has been studied. The phase relations and the sequences of solid phase reactions, which take place during the synthesis of stoichiometric manganites, have been determined in different conditions for the homogenization of components (mechanical mixing and chemical precipitation). The chemical precipitation of components as well as a prolonged heat treatment of their mechanical mixture has been shown to assist the formation of a single-phase microstructure. Structural parameters of lanthanum-strontium manganites (unit cell parameters, atomic coordinates, site occupation depending on the sintering temperature and strontium content х) have been refined.
The use of the sol-gel technique has been shown to allow the essential reduction of the synthesis temperature and fabrication of single-phase “soft” crystalline precipitates of nanoparticles for the cathode materials.
Films of the lanthanum strontium manganites have been fabricated by screen printing and magnetron sputtering methods, and their crystal-chemical properties have been studied. The screen printing technique was shown to result in porous films with the controlled porosity. The electro-physical properties of films have been studied. Developed films have been applied onto the test samples simulating fuel cells, and their electrono-graphic investigation has been performed.
Oxygen-conducting bulk materials based on the stabilized zirconium oxide with the fluorite structure have been studied. These included the development of the fabrication technique for the films of oxygen-conducting materials, and study of the correlation between chemical composition, structure, electro-physical properties in order to optimize production of the materials as the electrolyte for a fuel cell.
The synthesis conditions for the films of stabilized zirconium oxide produced by a sol-gel technique have been studied, and electron conductivity of solid electrolyte has been measured over the wide range of partial oxygen pressure. Performed studies allowed the optimization of chemical composition and fabrication method of the film electrolyte layer for high-temperature fuel cell based on the stabilized zirconium oxide.
Keywords: Low-Temperature Fuel Cell, Cathode, Electrolyte, Anode, Use of Hydrogen.