Effect of WFe substitution on microstructures and electrochemical hydrogen storage properties of LaNi_(3.70)Co_(0.2–x)Mn_(0.30)Al_(0.15)Cu_(0.65)(W_(0.42)Fe_(0.58))_x alloys

作     者：马名杰 孙俊岭 范燕平 张宝庆 吉力强 刘宝忠 MA Mingjie;SUN Junling;FAN Yanping;ZHANG Baoqing;JI Liqiang;LIU Baozhong

作者机构：School of Materials Science and Engineering Henan Polytechnic University Inner Mongolia Rare Earth Ovonic Metal Hydride Co. Ltd. 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2015年第33卷第8期

页      面：850-856页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(51471065,U1304522) Program for New Century Excellent Talents in University(NCET-11-0943) Plan for Scientific Innovation Talent of Henan Province(144100510009) Fundamental Research Funds for the Universities of Henan Province(NSFRF140601) Foundation for University Key Teacher in the University of Henan Province(2011GGJS-052) 

主　　题：hydrogen storage alloy W0.42Fe0.58 alloy microstructure electrochemical property Ni/MH batteries rare earths 

摘      要：W0.42Fe0.58 alloy, instead of pure W and Fe, was used to substitute Co in LaNi3.70Co0.2Mno.3om10.15Cuo.65 alloy to improve the overall electrochemical properties with the decrement of the cost. Microstructures and electrochemical characteristics of LaNi3.70Co0.2-xMno.3oA10.15Cuo.65（W0.42Fe0.58）x （x=0.20） hydrogen storage alloys were characterized. X-ray diffraction patterns and backscattered electron images indicated that the pristine alloy was LaNi5 phase, while the alloys containing W0.a2Fe0.58 were made of LaNi5 matrix phase and W phase. The relatived abundance of W phase increased with the increase in x value. Lattice parameters a, c, c/a and cell volume V of LaNi5 phase increased with increasing x value. Activation property of the alloy electrodes was improved by substituting Co by Wo.42Fe0.58. As x increased from 0 to 0.20, maximum discharge capacity of alloy electrodes decreased from 335.4 （x=0） to 320.7 mAh/g （x=0.20）. The high-rate dischargeability at the discharge current density of 1200 mA increased from 59.8% （x=0） to 76.8% （x=0.10）, and then decreased to 64.7% （x=0.20）. The cycling capacity retention rate at the 100th cycle decreased from 80.4% （x=0） to 55.8% （x=0.20）, which should be ascribed to the degradation of the corrosion resistance and electrochemical kinetics of alloy electrodes.