Fuel cells

The paper analyzes the energy balance of the solid oxide fuel cell (SOFC) battery. The existence of three temperature points satisfying the equation of SOFC battery energy balance is found out. The first point is trivial and corresponds to the cooled state of the battery. The second temperature point corresponds to an unstable state of the battery and finally, the third point is stable and corresponds to the normal operating state of the battery. The difference between the third and second point defines the temperature interval within the battery is able to self-heating. Analogy with the Semenov diagram for chemical reactors is noted.

The paper generalizes a many years' experience in manufacturing and testing of multicell PHOTON stacks based on hydrogen-oxygen alkaline matrix fuel cells. Inter-cell processes effecting the stack lifetime are concerned, the main of which is the current flow between cells along a thin electrolyte film in gas collectors. This process is accompanied by electrolyte redistribution among elements resulting in their polarity reversal, and electrochemical corrosion in metal gas collectors of stacks.

The core-shell type catalysts were obtained by spontaneous surface substitution of electrodeposited Pb, Ni and Cu by platinum metals Pt-Ru. The surface layer of obtained catalysts was tested by EDAX; the amount of platinum was determined by ICP-AES. The catalytic activity of obtained catalysts was examined in methanol oxidation reaction. The stationary state currents were referred to EAS, determined from hydrogen adsorption. For all investigated systems the catalytic effect was registered thus confirming the activity of core–shell catalyst.

The study of the anodic oxidation of borohydride-ion BH₄^– on catalytically active nickel electrode by methods of potentiostatic inclusion, galvanostatically inclusion, cyclic voltammetry and infrared spectroscopy with Fourier transformation. The composition of some intermediates of the process of electrochemical oxidation of BH₄^– and the mechanism of decomposition of borohydride, which includes the following basic stages: BH₄^– → BH₃(OH)^– → BH₂(OH)₂^– → BH(OH)₃^– → B(OH)₄^–, is determined. The regularities of the kinetics of the electrochemical oxidation of BH₄^– – ion Ni-electrode is determined. The diffusion coefficient BH₄^– ion in aqueous solution at a temperature of 25°C, measured by electrochemical methods, ranges from 5.3·10^–5 to 1.6·10^–5, the average value of 2·10^–5 cm²/s.