Influence of magnesium content on structure and electrochemical properties of La_(1-x)Mg_xNi_(1.75)Co_(2.05) hydrogen storage alloys

作     者：蔡鑫 魏范松 胥小丽 张玉 CAI Xin;WEI Fansong;XU Xiaoli;ZHANG Yu

作者机构：School of Materials Science and Engineering Jiangsu University of Science and Technology 

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

年 卷 期：2016年第34卷第12期

页      面：1235-1240页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：Project supported by the National Natural Science Foundation of China(50901036) the Graduate Science and Technology Innovation Project of Jiangsu University of Science and Technology(YCX15S-18) Priority Academic Program Development of Jiangsu Higher Education Institutions 

主　　题：A5B19-type hydrogen storage alloy phase structure electrochemical properties rare earths 

摘      要：La（1-x）MgxNi（1.75）Co（2.05）（x=0.07, 0.08, 0.10, 0.13, 0.15） alloys were prepared by high-frequency inductive method, and then their structure and electrochemical properties were investigated systematically. The XRD analysis revealed that the alloys consisted of LaNi5 phase and La4MgNi（19）（Ce5Co（19） ＋ Pr5Co（19）） phase, and the introduction of Mg could promote the formation of La4MgNi（19） phase. The observation of microstructure showed that all the alloys processed dendritic structure, which was refined with the increase of x value. The electrochemical measurements showed that all the alloys could be activated within 2 cycles, and with increasing x, the maximum discharge capacity obviously increased from 254.00 m Ah/g（x=0.07） to 351.51 mAh/g（x=0.15）, but the cycling stability（S（80）） decreased somehow from 78.4% to 73.9%. Meanwhile, the appropriate addition of Mg could improve the high-rate discharge capacity（HRD） of the alloy electrodes, which was mainly controlled by the electrochemical reaction rate on the surface of the alloys.