Electrochemically active species in aluminum electrodeposition baths of AlCl3/glyme solutions

Abstract

Electrochemically active species in aluminum (Al) electrodeposition baths using AlCl3 and less volatile solvents i.e. glymes were investigated. Raman spectroscopy revealed that all the glyme baths contained AlCl4-anions and Al-Cl-glyme cations as ionic species. Room temperature conductivities were as high as the order of 10-3 S cm-1 for the diglyme (G2), triglyme (G3) and tetraglyme (G4) baths, whereas that for the butyl diglyme (butylG2) bath was only 10-4 S cm-1 due to a lower concentration of ionic species. Surprisingly, electrochemical measurements showed that, among the glyme baths, only the G2 bath enabled electrodeposition of Al. Consequently, despite the similar structures of Al-Cl-glyme complex cations, only the G2 complex cations are electrochemically active. This suggests that the desolvation of glymes from Al-Cl-glyme cations and their subsequent reduction is exceptionally easy for the G2 complexes. We changed to "; in the case of potentiostatic electrodeposition at-1 V vs. Al QRE [47] the XRD profiles also show the deposits were crystalline Al.".

An Investigation of the Symmetric and Asymmetric Cleavage Products in the System Aluminum Trihalide/1‐Butylimidazole

“…[31,38,50] Experimental Section Experimental details, 1D and 2D NMR, and vibrational spectra of all mixtures, and crystallographic detailsh ave been deposited in the SupportingI nformation. The first observation indicates that the use of AlBr 3 for the synthesis of novel mixtures/solutions could be beneficial, as more weakly coordinatingl igands/solvent molecules can be used for the formation of [Al(L) 6 ] 3 + .T his could be an advantage for the deposition of aluminum from this cation, as strongly coordinating ligandsp reventt he electrodeposition of aluminumfrom cationic aluminum complexes.…”

“…This discrepancy is explained by the presence of the active species[ Al 2 Cl 7 ] À at 70 8C and its absence at room temperature, whichc ould be proven by 27 Al NMR spectroscopy. [37,38] As triglyme (G3) has four ether oxygen atoms, no second donor molecule is neededt of ormah exacoordinated complex [AlCl 2 (G3)] + .T he ligand is harder to dissolve due to the better chelating effect, resulting in the formation of an electrochemically inactive monocation.A ll other deposition experiments were performedw ith Lewis acidic mixtures, and the proposed active species are either cationic or the anion [Al 2 Cl 7 ] À .T he preceding discussion suggests that the exact mechanism and the influence of the ligand on the deposition of aluminumf rom AlCl 3 -based mixtures is still open to debate. of aluminum is six, as the active species.…”

“…4-Pr-Py [g] 0.5750 ++ [AlCl 2 (L) n ] + (n = 1, 2) 3, 4cationic [32] 1-Bu-Pyrr [h] 0.5525 ++ [AlCl 3Àn (L) x ] + 1, 2cationic [40] G2 [i] 0.1725 ++ [AlCl 2 (L) 2 ] + 6cationic [37,38] G3 [j] 0.1725 --[ AlCl 2 (L) n ] + 6 [37,38] [a] N,N-Dimethylacetamide. compensated by the higherd ensities of the bromoaluminate systems.…”

Halogenid‐basierte Materialien und Chemie für wiederaufladbare Batterien

“…Der zweite Elektrolyttyp, das Eutektikum aus AlCl 3 /organischem Lösungsmittel, wird durch Auflösung von wasserfreiem AlCl 3 in Amid‐, Sulfon‐ oder Glyme‐basierten Lösungsmitteln in einer inerten Atmosphäre hergestellt . Diese Elektrolyte sollen eine kostengünstige, weniger korrosive Alternative zu den AlCl 3 /Chlorid‐basierten ionischen Flüssigkeiten sein.…”

“…Ein anderes Eutektikum aus AlCl 3 /organischem Lösungsmittel mit ähnlicher Koordinations‐ oder Lösungsfunktion wie der AlCl 3 /Amid‐Elektrolyt ist der AlCl 3 /Diglyme‐Elektrolyt, der ebenfalls reversible Al‐Abscheidung und Auflösung erzeugen kann . Die aktive Spezies in diesem Elektrolyten soll ausschließlich das Sechs‐O/Cl‐koordinierte AlCl 2 (Diglyme) 2 + ‐Kation sein, welches mit dem inaktiven AlCl 4 − ‐Anion gepaart ist.…”