Aluminium/zirconium alloys obtained by Al underpotential deposition onto Zr from low temperature AlCl3+NaCl molten salts

Contrary to the widely accepted hypothesis that it is not possible, aluminium underpotential deposition (UPD) onto zirconium from a low temperature (200, 250 and 300?C) equimolar chloroaluminate melt was recorded. Furthermore, it was shown that aluminium UPD facilitates alloy formation between the deposited aluminium monolayer and the zirconium substrate by interdiffusion. The aluminium/zirconium alloys formed at the temperatures substantially lower than those needed for thermal preparation of the same alloys were: Al3Zr2 and Al3Zr. Experimental techniques used were linear sweep voltammetry, potential step, scanning electron microscope, energy dispersive spectroscopy and X-ray diffraction were used for characterization of obtained electrode surfaces.

Electrodeposition of Nb and Al from chloroaluminate melt on vitreous carbon

Niobium and aluminium were electrodeposited at 200 °C under argon atmosphere onto vitreous carbon from inorganic chloroaluminate melts (AlCl3+NaCl) with added niobium. Niobium was introduced into the electrolyte by anodic dissolution of metallic niobium or by chemical dissolution of Nb2O5 in a melt of equimolar AlCl3+NaCl mixture. The processes of deposition/dissolution onto/from vitreous carbon were investigated by cyclic voltammetry and chronoamperometry. Characterization of the obtained deposits was done by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The only observed reduction processes on the working electrode in the potential window from 1.000 V to – 1.000 V vs. Al, were individual niobium deposition and codeposition of niobium and aluminium with Al-Nb alloys formation. Electrodeposition of niobium from the chloroaluminate melt with added niobium (V) oxide seems to start at around – 0.100 V vs. Al and at about – 0.200 V vs. Al aluminium starts codepositing. During the codeposition Nb-Al alloys were formed. Niobium deposition starting potential from the electrolyte with niobium added by anodic dissolution starts at 0.100 V vs. Al, and aluminium codeposition starting potential was at around – 0.025 V vs. Al, followed by Nb/Al alloy formation.

Dual Intercalating Molten Electrolyte Batteries

ABSTRACTDual Intercalating Molten Electrolyte (DIME) electrodes and cells have been examined using a number of low-melting and room-temperature molten salts. A cell with a chloroaluminate melt achieved a cycling efficiency of 85% with a discharge voltage of 2.92 V. Coke-elastomer composite electrodes underwent cation reductive intercalation without experiencing the exfoliation and degradation seen for graphite rods. Theoretical studies for an imidazolium-graphite intercalate predict the graphite layer spacing expands between 5.18 and 8.01 Å upon insertion of the imidazolium molecule into the graphite lattice.