коррозия

The influence of lithium-fluorocarbon glass leads on the stability and preservation, as well as the behavior of differentcurrent leads of insulator is studied. It is shown that the most resistant glass for lithium output is silicon-free glass C62. The behavior of the fluorocarbon cathode current lead (titanium, niobium, molybdenum-rhenium) during storage is investigated. Discovered high corrosion niobium current lead correlation between OCV element and the intensity of corrosion of niobium current lead.

УДК 541.135

DOI: https://doi.org/10.18500/1608-4039-2016-16-2-77-87

The review deals with studies of the properties of lead alloys used to fabricate electrode grids of sealed lead-acid batteries.

The phase composition, conductivity and corrosion resistance under the Molten Carbonate Fuel Cell (MCFC) operating conditions of synthesized using common ceramic and cocrystallization techniques samples of LaLi_0.1Со_0.1Fe_0.8O_{3 – δ} have been studied. It was found, that the phase composition of synthesized by ceramic technique sample differed from the nominal composition. This difference arose from the formation of complex oxide (La_1-yLi_y)(Li_0.1-yCo_xFe_{0.9 – x})O_{3 – δ'}, y ≤ 0.1, and La₂O₃. Synthesized by cocrystallization technique sample was found to be of single phase. Its conductivity differed from the conductivity of two phase sample. Under MCFC operating conditions the difference in properties of synthesized by both techniques samples diminished and converged towards the properties of the sample prepared by ceramic technique.

Corrosion behavior of niobium current leads of fluorocarbon-lithium cells are studied. Polarization measurements at plain niobium leads and at such leads in a contact with fluorocarbon cathode in an electrolyte of fluorocarbon-lithium cell were carried out. Besides, behavior of niobium lead directly in a feedthrough of real cells was studied. The contact of niobium with fluorocarbon cathode is shown to result in toughening of corrosion conditions and in possible niobium depassivation. Long-term cells storage at elevated temperature was shown to result in complete corrosion dissolution of niobium leads. Certain correlation between cell's OCV and corrosion intensity was obtained.

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.