Ananth, M.V. and Ganesan, M. and Renganathan, N.G. and Lakshmi, S. (2009) Influence of rare earth content on electrode kinetics in Misch metal-based AB5 MH alloys – Cyclic voltammetric investigations. International Journal of Hydrogen Energy , 34 (1). pp. 356-362. ISSN 0360-3199

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Abstract

The influence of lanthanum/cerium ratio (0.42–14.14) in Misch metal (Mm)-based AB5-type hydrogen storage alloys has been investigated. The samples were subjected to X-ray florescence (XRF) and cyclic voltammetry (CV) studies. The metal hydride electrodes were assembled, and their discharge capacity was determined. These alloys delivered discharge capacity between 118 and 266 mAh/g. CV investigations threw light on charge-transfer reactions at the electrode/electrolyte interface and hydrogen surface coverage capacity. The CV parameters in general indicate that the battery activity increases with lanthanum/ cerium ratio. At low lanthanum/cerium values, the discharge reactions proceed at potentials that are more negative. Furthermore, electrochemical reversibility of the hydrogen absorption–desorption on the alloy surface is enhanced at optimum lanthanum/cerium ratio as revealed by decreasing values of peak separation. The slopes of graphical plots of Ipeak (anodic) vs. n1/2 for the fully charged samples reverse direction at very high lanthanum/cerium values. The results suggest that the discharge plateau is optimum at lanthanum/cerium ratio around 12.

Item Type:	Article
Uncontrolled Keywords:	Hydrogen storage alloy; Lanthanum/cerium ratio; X-ray florescence; Cyclic voltammetry; Electrokinetic properties
Subjects:	Electrochemical Power Sources
Divisions:	UNSPECIFIED
Depositing User:	TTBD CECRI
Date Deposited:	01 Apr 2012 17:52
Last Modified:	01 Apr 2012 17:52
URI:	http://cecri.csircentral.net/id/eprint/367

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