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Electrochemical behaviour of aluminium in non-aqueous electrolytes over a wide potential range

Suresh, P and Shukla, AK and Shivashankar, SA and Munichandraiah, N (2002) Electrochemical behaviour of aluminium in non-aqueous electrolytes over a wide potential range. In: Journal of Power Sources, 110 (1). pp. 11-18.

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Abstract

The electrochemical behaviour of aluminium in LiClO4-propylene carbonate electrolyte is studied by cyclic voltammetry, steady-state polarisation, and ac impedance spectroscopy in the potential range -0.4-4.2 V versus Li/Li+. The open-circuit potential of Al is 1.57 V versus Li/Li+, which is about 0.2 V above the thermodynamic value of Al due to the presence of a surface passive film. In the positive potential region, Al is fairly stable between 1.57 and 3.5 V versus Li/Li+ owing to the presence of the surface film. Nevertheless, the oxidation of Al occurs at potentials >3.5 V versus Li/Li. The ac impedance data are analysed by using a non-linear least-squares fitting procedure, and the surface film resistance is found to be between 498 and 1032 kOmega cm(-2) In the potential range 3.6-4.2 V versus Li/Li+, there is a breakdown of the passive film as demonstrated by a decrease in its resistance to 1.2-4.8 kOmega cm(-2). This breakdown accompanies anodic oxidation of Al. Thus, there is a possibility of anodic degradation of the Al substrate that is usually used as the current-collector of positive electrodes of Li-ion batteries, if Al is exposed to the electrolyte. In the negative potential region, the deposition of uniform and non-dendritic Li occurs, which can be anodically stripped in a quasi-reversible process with high coulombic efficiency. Diffusion of Li into Al results in the formation of a surface layer of Li-Al alloy, as suggested by X-ray diffraction patterns. The quasi-reversible cathodic deposition and anodic stripping of Li with an exchange current density of 0.16 mA cm(-2) indicates that Al is useful as a negative electrode in Li-batteries. (C) 2002 Elsevier Science B.V. All rights reserved.

Item Type: Journal Article
Additional Information: Copyright of this article belongs to Elsevier Science.
Keywords: Nonaqueous Electrolyte;Current Collectors;Corrosion;Lithium.
Department/Centre: Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited: 02 Jun 2009 12:33
Last Modified: 19 Sep 2010 05:01
URI: http://eprints.iisc.ernet.in/id/eprint/18356

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