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Interest in the use of ion modification methods of anode materials for solid oxide fuel cells is primarily due to the possibility of enhancement of electrochemical parameters, as well as improvement of strength properties. Strengthening of ceramics occurs due to the formation of additional barriers in the surface layer, created by a high density of dislocations, the presence of which restrains the spread of microcracks near grain boundaries, and also increases resistance to corrosion processes that occur during the use of ceramics as anodic materials. At the same time, the search for optimal modification conditions is one of the key areas of research aimed at enhancement of the efficiency of using solid fuel oxide elements, as well as prolongation of their service life, which in turn will reduce the costs of their operation and replacement.
In this paper, a method for obtaining anode materials for solid fuel oxide elements by mechanochemical solid-phase mixing of zinc and titanium oxides in various stoichiometric ratios, followed by thermal annealing, which results in the initialization of phase transformation processes, is proposed. To modify the obtained ceramics, a method of ion modification, which consists of irradiation of the ceramics with O+ ions with an energy of about 28 MeV and fluences from 1011 to 1014 ion/cm2, was proposed.
During the conducted tests of the evaluation of the electrochemical parameters of the synthesized and modified ceramics based on zinc titanate, it was established that the change in the phase composition of the ceramics due to the dominance of ZnTiO3 leads to a growth in the specific power value, the change of which is due to the increase in charge carriers in the composition of the ceramics. Moreover, in the case of modified ceramics, the greatest increase in the value of Pmax is observed for samples obtained by mixing ZnO and TiO2 in equal weight proportions, in which the phase composition of the ceramics is represented by a mixture of two phases: cubic ZnTiO3 and the tetragonal phase of rutile (TiO2). In this case, ionic modification leads to the formation of additional charge carriers due to ionization processes in the structure of ceramics, and the created structural defects and the presence of interphase boundaries in the composition of ceramics inhibit the processes of deformation swelling and subsequent destruction during long-term operation in high-temperature conditions.
The results obtained make it possible to conclude that the proposed compositions of composite ceramics based on zinc titanate, obtained by the method of mechanochemical solid-phase synthesis, have quite large prospects for their use as anode materials for solid oxide fuel cells. At the same time, the use of ion modification methods makes it possible to enhance the efficiency of electrochemical parameters, as well as increase resistance to external influences.
