Vol 25, No 4 (2025)

The optimal conditions for the synthesis of Na4Nb8P4O32 were found and the phase composition, morphology and electrochemical properties were studied in this work. The effect of the temperature and the synthesis time on the phase composition of Na4Nb8P4O32 were shown. According to the X-ray phase analysis data the optimal synthesis conditions were 900°C and 2.5 hours. The values of ionic and electronic conductivity were 2.7 · 10−7 S/cm and 6.1 · 10−6 S/cm, respectively. The obtained values of the charge and discharge capacities were 43 mA·h/g and 44 mA·h/g, respectively.

Microtubular membranes with the composition of La0.6Sr0.2Ba0.2Fe0.7Ni0.1Co0.2O3−δ were fabricated using phase inversion and dip- coating methods, followed by sintering in air. The obtained microtubular membranes were characterized by X-ray diffraction analysis and scanning electron microscopy. The optimal sintering temperature was selected taking into account the target application of the microtubular membranes and the corresponding microstructural requirements. The comparative analysis was performed based on the following parameters: inner and outer diameter, shrinkage, and the dimensions of the gas-tight and porous layers.

A new design of the interconnect for tubular solid oxide fuel cells was presented. The functions of electrical connection and mechanical/gas distribution were separated in this interconnect. The electrical connection of the elements was provided by a separate metal wire laid around the frame. The paste composition and parameters for inkjet 3D printing, as well as the sintering regime, were optimized, enabling the production of dense samples with high microhardness. This approach allows for the use of Zr0.9Y0.1O1.95 (YSZ) material, which is chemically and thermally compatible with the electrolyte, eliminating the conductivity and corrosion problems taking place in traditional interconnects.

Solid polymer electrolytes are one of the promising materials for solid-state supercapacitors. In this work, the solid polymer electrolytes PU-PFL100 were obtained based on polyurethane elastomer filled with LiBF4 solution in N-methyl-2-pyrrolidone. Using cyclic voltammetry and galvanostatic charge/discharge methods, it was shown that Ti3C2/AC//PU-PFL100//Ti3C2/AC symmetrical supercapacitor cells, in which the composite based on Ti3C2 with activated carbon is used as electrodes, and PU-PFL100 is used as electrolyte and separator, exhibit specific capacitance of 34.5 F/g at a scan rate of 5 mV/s at the room temperature.

In this work, the effect of humidity on the microstructural degradation of nickel-based metal– ceramic composite materials containing 0, 10, 20, 40, and 60 wt.% of cobalt in the metallic phase was investigated. The increase in cobalt concentration was found to have a beneficial effect on the stability of the microstructure and the long-term electrical conductivity, indicating the perspective of cobalt alloying as an approach to improve the performance and durability of SOFC anodes.