Optimization of the La substitution by Mg in the La2Ni7 hydride-forming system for use as negative electrode in Ni-MH battery

被引：35

作者：

Gal, Lucille ^{[2
]}

Charbonnier, Veronique ^{[1
]}

Zhang, Junxian ^{[1
]}

Goubault, Lionel ^{[2
]}

Bernard, Patrick ^{[2
]}

Latroche, Michel ^{[1
]}

机构：

[1] ICMPE CNRS UPEC UMR7182, F-94320 Thiais, France

[2] Direct Rech, SAFT, F-33074 Bordeaux, France

来源：

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY | 2015年 / 40卷 / 47期

关键词：

La2Ni7 intermetallic compounds; Metallic hydrides; Electrochemical properties; NiMH batteries; ELECTROCHEMICAL PROPERTIES; HYDROGEN; ALLOYS; LA2MGNI9;

D O I：

10.1016/j.ijhydene.2015.06.068

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The crystallographic, thermodynamic and electrochemical properties of the hydrogen-sorbing system La2-xMgxNi7 has been examined as a function of x. X-ray diffraction shows the coexistence of two polymorphic structures, hexagonal (P6(3)/rnmc) and rhombohedral (R-3m), for the same compositions as already observed for other systems La-Mg-Ni. Thermodynamic properties regarding hydrogen uptake have been determined by means of solid gas reaction. Capacity and equilibrium pressure have been measured and electrochemical properties in alkaline medium have been determined as a function of the magnesium content. Mg-free compound exhibits much lower reversible electrochemical capacity than the Mg-containing one and an optimum Mg composition has been obtained around 25 at.% Mg sitting on the lanthanum site. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

引用

页码：17017 / 17020

页数：4

共 21 条

[1] Structural Stability of ABy Phases in the (La,Mg)-Ni System Obtained by Density Functional Theory Calculations [J].