DocumentCode :
2699857
Title :
Electrochemical hydrogenation of LaY2Ni9 anode at C/3 and C/10 discharge rates for nickel-metal hydride batteries
Author :
Ben Belgacem, Yassine ; Khaldi, Chokri ; Lamloumi, Jilani
Author_Institution :
Lab. de Mec. Mater. et Procedes, Univ. de Tunis, Tunis, Tunisia
fYear :
2015
fDate :
24-26 March 2015
Firstpage :
1
Lastpage :
6
Abstract :
The electrochemical hydrogenation of the LaY2Ni9 alloy as a negative electrode material of a nickel-metal hydride accumulator has been investigated at C/3 and C/10 rates. For this case, several electrochemical methods such as the galvanostatic charging and discharging (chronopotentiometry), the constant potential discharge (chronoamperometry), and the cyclic voltametry were used to investigate the hydrogen absorption-desorption and electrochemical properties. The decrease of the discharge rate makes the maximum discharge capacity greater and activation cycle number smaller. The evolution of the potential difference with the decrease of the discharge rate can be correlated with both the maximum discharge capacity and the cycle number of activation. The electrochemical discharge capacity undergoes an important increase during first cycles attributed to the activation of the alloy, then it decay gradually with increasing cycling. This decreasing becomes more important with C/3 rate. The evolution of the redox parameters and the diffusion coefficient (DH/a2) is correlated with the activation phenomenon which confirm the good results obtained by the C/10 rate, knowing that the cycling plays a role of stripping the surface of the electrode, that is to say the removal of a continuous manner of oxides from the surface of the electrode, engendering a reduction of its thickness.
Keywords :
electrochemical electrodes; hydrogenation; lanthanum compounds; secondary cells; voltammetry (chemical analysis); LaY2Ni9; chronoamperometry; chronopotentiometry; constant potential discharge; cyclic voltammetry; electrochemical discharge capacity; electrochemical hydrogenation; electrochemical properties; galvanostatic charging and discharging; hydrogen absorption-desorption; negative electrode material; nickel-metal hydride accumulator; nickel-metal hydride batteries; Batteries; Current density; Discharges (electric); Electric potential; Electrodes; Hydrogen; Metals; diffusion coefficien; discharge capacity; electrochemical hydrogenation; redox parameters;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Renewable Energy Congress (IREC), 2015 6th International
Conference_Location :
Sousse
Type :
conf
DOI :
10.1109/IREC.2015.7110879
Filename :
7110879
Link To Document :
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