Caracterización Electroquímica de Aleaciones usadas en Electrodos Metal Hidruro

RITA M. HUMANA.; JORGE E. THOMAS; FABRICIO RUIZ; ELIDA B. CASTRO; ARNALDO VISINTIN.

Revista Científica de Educación

Facultad de Ciencias Exactas y Naturales

Lugar: San Fernando del Valle de Catamarca; Año: 2011 vol. 6 p. 27 - 37

1668-2009

Metal hydride (MH) intercalation materials, are of great scientific and technological interest due to their implementation as negative electrodes in alkaline Ni/MH rechargeable batteries. The search for new hydride forming materials of adequate composition and structure to enhance the performance of the negative electrode in the Ni/MH battery, remains a matter of research. The behavior of the negative electrode in rechargeable alkaline Ni/MH batteries, depends on factors such as hydrogen storage capacity, kinetics of the hydriding process and transport of hydrogenwithin the bulk of the metal alloy. The aim of this work is to study the possibility of improving the behavior of MH electrodes by changing their composition and preparation procedure. The study is focused on the effect of the particle size of the alloy powder, in order to determine the particle size range that offers the best performance for the hydriding process, for electrodes based on AB2 and AB5 type alloys. The electrochemical characterization of the electrodes, performed with techniques such discharge capacity determination, charge/discharge cycling, rate capability determination and electrochemical impedance spectroscopy, EIS, indicates that the composition and particle size of the alloy influence the hydrogen absortion (HAR) and hydrogen evolution(HER) processes.