TY  - JOUR
AU  - Meister, Paul
AU  - Qi, Xin
AU  - Kloepsch, Richard
AU  - Krämer, Elisabeth
AU  - Streipert, Benjamin
AU  - Winter, Martin
AU  - Placke, Tobias
TI  - Anodic Behavior of the Aluminum Current Collector in Imide-Based Electrolytes: Influence of Solvent, Operating Temperature, and Native Oxide-Layer Thickness
JO  - ChemSusChem
VL  - 10
IS  - 4
SN  - 1864-5631
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2017-02794
SP  - 804 - 814
PY  - 2017
AB  - The inability of imide salts to form a sufficiently effective passivation layer on aluminum current collectors is one of the main obstacles that limit their broad application in electrochemical energy-storage systems. However, under certain circumstances, the use of electrolytes with imide electrolyte salts in combination with the aluminum current collector is possible. In this contribution, the stability of the aluminum current collector in electrolytes containing either lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) or lithium fluorosulfonyl-(trifluoromethanesulfonyl) imide (LiFTFSI) as conductive salt was investigated by electrochemical techniques, that is, cyclic voltammetry (CV) and chronocoulometry (CC) in either room-temperature ionic liquids or in ethyl methyl sulfone. In particular, the influence of the solvent, operating temperature, and thickness of the native oxide layer of aluminum on the pit formation at the aluminum current collector surface was studied by means of scanning electron microscopy. In general, a more pronounced aluminum dissolution and pit formation was found at elevated temperatures as well as in solvents with a high dielectric constant. An enhanced thickness of the native aluminum oxide layer increases the oxidative stability versus dissolution. Furthermore, we found a different reaction rate depending on dwell time at the upper cut-off potential for aluminum dissolution in TFSI- and FTFSI-based electrolytes during the CC measurements; the use of LiFTFSI facilitated the dissolution of aluminum compared to LiTFSI. Overall, the mechanism of anodic aluminum dissolution is based on: i) the attack of the Al2O3 surface by acidic species and ii) the dissolution of bare aluminum into the electrolyte, which, in turn, is influenced by the electrolyte's dielectric constant.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000397006500020
C6  - pmid:28127874
DO  - DOI:10.1002/cssc.201601636
UR  - https://juser.fz-juelich.de/record/828977
ER  -