Liquid-Phase Synthesis and Physical and Chemical Properties of Ceramic Electrolyte Nanomaterials in the CeO_2-Sm_2O_3 System for Solid Oxide Fuel Cells

摘要

By the method of joint crystallization of solutions of nitrate salts, the highly dispersed powders of the composition (CeO_2)_(0 98)(Sm_2O_3)_(0.02, (CeO_2)_(0.95)(Sm_2O_3)_(0.05), and (CeO_2)_(0.90)(Sm_2O_3)_(0.10) are synthesized, and on their basis, nanoceramic materials with a crystalline cubic structure of f luorite type are obtained, with the grain size of the crystallites of-68-81 nm (1300°C). Their mechanical and electrophysical properties are studied; it is found that they have an open porosity of 2-6% and predominantly ionic (t_i= 0.82-0.71 in the range of 300-700°C) type of electrical conductivity due to the formation of mobile oxygen vacancies during the heterovalent replacement of Ce~(4+) with Sm~(3+), σ_(700°C) =1.3 × 10~_(-2) S/cm. The studies show the prospects of using the obtained ceramic materials as solid oxide electrolytes of intermediate-temperature fuel cells.