Фазовый состав, микроструктура и электропроводность твердых электролитов HfO_2-R-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- (R=Sc, Y, Ho, Er, Tm, Yb, Lu)

The effect of the addition of 11 mol % R2O3 (R = Sc, Y, Ho, Er, Tm, Yb, Lu) on the phase and elemental composition, microstructure, and electrical conductivity of hafnium oxide was studied. When all additives, with the exception of scandium, are introduced into HfO2, solid solutions with a cubic structure such as fluorite are formed. The HfO2-Sc2O3 sample is an Hf7Sc2O17 phase having a fluorite-type lattice with rhombohedral distortions that undergoes reversible changes in the cubic structure at a temperature of ~ 760 ° C. It has been established that the nature of the dopant practically does not affect the microstructure of the HfO2-R2O3 ceramics; all samples are coarse-grained with a grain size of up to 10 μm. It was shown that the conductivity of HfO2-R2O3 samples is determined by the volume of grains. The most promising materials for use as a solid oxide electrolyte are HfO2-Tm2O3 and HfO2-Yb2O3, in which high conductivity is combined with structural stability.

Promising Osmotic and Hybrid Electrochemical Power Plants

A range of energy technologies ultimately aimed at obtaining electric energy is considered. Proceeding from the list of considered sources, it is possible to analyze their different combinations for achieving better energy efficiency of new complexes. A systematic list of 21 currently known traditional, non-traditional, and renewable energy sources is compiled. Each of them taken individually has an efficiency not exceeding 50%, except for some types of fuel cell based power facilities. Block diagrams of energy flow conversion stages are proposed for the considered kinds of sources. Obviously, if some or other chain does not contain certain blocks in comparison with the first classical chain of thermal engine thermodynamic cycles, this means that the missing energy conversion stages of are either implemented covertly, or proceed in the environment. As an example, two promising sources are considered: an osmotic hydroelectric power plant and a hybrid power plant (HybPP) based on high-temperature fuel cells with solid oxide electrolyte and a gas turbine unit. In fact, an osmotic hydroelectric power plant takes the solar energy spent for evaporation from sea surfaces in the form of the osmotic pressure phenomenon energy under the conditions of one-way diffusion of fresh river water (a solvent) molecules through a semi-permeable membrane towards salt sea water (a solution). An osmotic HPP is a combination of a reservoir with semi-permeable membranes and an HPP. The former is characterized by the expected high specific power up to 12 kW per square meter of semi-permeable membrane area, and the latter is characterized by the highest efficiency among all types of electric power sources and by the high achieved specific power up to 2-3 kW per square meter of solid oxide electrolyte surface area.

High oxide ion conductivity in layer-structured Bi4Ti3O12-based ferroelectric ceramics

B0.97T0.73Mg0.02 shows high oxide ion conductivity, which is comparable to that of other leading solid oxide electrolyte materials.

High Li+ transference gel interface between solid-oxide electrolyte and cathode for quasi-solid lithium-ion batteries

A gel electrolyte outperforms liquid electrolytes in conveying Li+ across the pellet–cathode interface by eliminating solvent–ion clusters and immobilizing anions.