Anodic Aluminum Dissolution of LiTFSA Containing Electrolytes for Li-Ion-Batteries

In this study, novel electrolyte solvents and the conducting salt lithium bis(trifluoromethanesulfonyl)azanide (LiTFSA) are compared with respect to aluminum anodic dissolution, often called in an ambiguous manner aluminum corrosion. Namely, mixtures of propylene carbonate, sulfolane, the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)azanide (DMMA-TFSA) and various concentrations of LiTFSA are prepared and investigated in Al|Li cell configuration. It is verified that the choice of the concentration of LiTFSA and the composition of the solvent mixture affects the tendency of Al dissolution significantly. Principally, the best results (least dissolution/corrosion) are obtained in case of high LiTFSA concentrations and by adding the ionic liquid DMMA-TFSA to the organic solvents.