Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Anna Musiał-Gładysz"

Evaluation of the influence of Cu2O addition on electrochemical properties of LaNi5 hydrogen storage alloy DOI:10.15199/40.2018.5.1

  1. Introduction The literature review shows that the maximum limit of hydrogen storage capacity for alloys obtained on the basis of LaNi5 intermetallic compound is approx. 1.5 wt.% [10] and it is difficult to expect significant improvement in the hydrogen capacity in this group of materials. However, the basic criterion of an alloy usability as a material for the negative electrode of a hydride cell comprises not only high hydrogen solubility in the alloy crystal lattice, but also a quick transport of hydrogen atoms inside the solid phase (high diffusion coefficient) and a quick rate of the electron transition reaction (high value of exchange current density of the H2O/Hads system). The hydrogen absorbing ability and its mobility within the crystal lattice are characteristics of the material inside and to some extent they can be improved only by changing the material’s composition and structure, but the charging/discharging process kinetics can be substantially improved, primarily via proper modification of the electrode surface. The provision of catalytic properties to a hydrogen-absorbing material has a big practical importance, because on the one hand it enables drawing significant currents from the cell, and on the other hand - allows to significantly shorten the charging time. For this purpose the alloys are most frequently subject to etching in an acid [8] or microencapsulation (deposition of thin Cu, Ni, Pd, Ru, Ni-P, Co-P etc. films on the surface of particles) [13-15]. More and more frequently an alkaline solution containing a small amount of a reducing agent is used to improve catalytic properties of alloys in the process of hydrogen absorption [1]. Also the blending of hydrogen-absorbing alloy powders with certain metal oxides results in the improvement in the electrocatalytic activation of the electrode. Results of examinations presented in paper [9] show that blending a powder of AB5 type alloy (MmNi3.6Mn0.4Al0[...]

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