Vol 24, No 4 (2024)

The electrochemical characteristics of the tubular solid oxide fuel cells (SOFC) and the symmetrical anodic cells with conventional nickel-cermet and modified nickel-cobalt cermet anodes were studied using voltammetry, electrochemical impedance spectroscopy, and distribution of relaxation time analysis. The tubular SOFC with the modified anode exhibited higher power output and demonstrated lower power loss at reduced temperatures, which is attributed to higher electrical conductivity and lower activation energy of the anodic electrode reaction.

The search for solvents to prepare polymer electrolytes based on polyurethane elastomer by swelling method was carried out. The greatest swelling was observed in N-methyl-2-pyrrolidone, and the maximum degree of swelling was reached in 24 hours at 25°C. The swelling effect decreased with increasing the salt concentration. The ionic conductivity of the polymer electrolytes reached the maximum of 6–8·10-4 S/cm at 5 wt% of lithium salt. Using the method of galvanostatic cycling it was shown that the electrolyte was reversible by lithium ions and electrochemically stable in the voltage range up to 4.8 V

In this work, a microtubular cell with an LNO-SDC-based air electrode fabricated using the phase inversion method was investigated. The microstructure of a single cell was characterized using scanning electron microscopy. The electrochemical parameters were measured in the mode of co-electrolysis of water steam and carbon dioxide. The obtained results indicated the high efficiency of the microtubular cell.

The dependence of oxygen stoichiometry on the oxygen partial pressure and the temperature for La- and Nb-doped strontium ferrite La0.4Sr0.6Fe0.95Nb0.05O3 – δ (LSFNb5) was studied by quasi-equilibrium oxygen release (QEOR) method. The equilibrium diagram in the coordinates “T – lg(pO2 ) – 3 – δ” in the temperature range of 700–900°C and oxygen partial pressures pO2 = 10–4 – 0.2 atm was obtained. The range of stoichiometry deviation was determined, and the thermodynamic parameters of the oxygen release process were analyzed.

In this work, the supporting electrolytes for solid oxide fuel cells based on samarium doped cerium oxide Ce0.8Sm0.2O1.95 were fabricated using 3D inkjet printing and layer-by-layer laser treatment followed by thermal sintering. The samples were characterized by scanning electron microscopy, X-ray diffraction analysis and impedance spectroscopy. The Vickers hardness test and three-point bending flexural test were carried out. The developed approach allows for precise control of the layer thickness and microstructure, significantly facilitating the scaling of solid oxide fuel cells production, and reducing the loss of expensive ceramic materials.

To the 75th Anniversary Yury P. Zaikov