镍包覆改性 Mg_(1.8)M_(0.2)Ni (M=Ti, Zr, Si, Cu)储氢合金的电化学性能  

Electrochemical Properties of Nickel Coated Mg_(1.8)M_(0.2)Ni (M=Ti, Zr, Si, Cu) Hydrogen Storage Alloys

作　　者：侯占忠[1] 高贵军[1] 郭振福[1] 高晓娜 柏天新 杨桂玲[1] HOU Zhanzhong;GAO Guijun;GUO Zhenfu;GAO Xiaona;BAI Tianxin;YANG Guiling(Hebei North University,Zhangjiakou 075000,China)

机构地区：[1]河北北方学院,河北张家口075000

出　　处：《材料科学与工程学报》2018年第5期819-823,共5页Journal of Materials Science and Engineering

基　　金：张家口市科学技术和地震局资助项目(12110018B-2);河北北方学院重大资助项目(220311)

摘　　要：本文采用机械合金化法(MA),以M(M=Ti、Zr、Si或Cu)部分取代合金中的Mg,制备得到改性合金Mg_(1.8)M_(0.2)Ni,然后按1∶1比例用Ni进行包覆修饰,制备出Mg_(1.8)M_(0.2)Ni-1.0Ni储氢合金。结果表明,经Ti、Zr、Si、Cu部分取代Mg改性和用Ni包覆修饰后的储氢合金,非晶化程度得到显著提高,其电化学性能都得到改善,在循环稳定性以及高倍率放电性能方面,优于未改性合金。其中,Mg_(1.8)Ti_(0.2)Ni-1.0Ni和Mg_(1.8)Zr_(0.2)Ni-1.0Ni合金的初始放电比容量分别729.9mAh·g^(-1)和689.0mAh·g^(-1),大于Mg_(2.0)Ni-1.0Ni合金的初始放电比容量665.5mAh·g^(-1),而Mg_(1.8)Zr_(0.2)Ni-1.0Ni表现出更好的循环稳定性,100个循环后,放电比容量仍保持400mAh·g^(-1)左右。通过对Mg_(1.8)M_(0.2)Ni-1.0Ni(M=Ti、Zr、Si、Cu)进行线性极化、阳极极化和交流阻抗的测试,进一步研究了该系列改性合金的电化学性能。To improve the electrochemical properties of hydrogen storage alloy Mg2Ni, Mg was partially substituted with M=Ti、Zr、Si、Cu, and Mg1.8M0.2Ni alloys were prepared by mechanical alloying（MA）. Adding Ni into the alloy, Ni coated alloy with the molar ratio of 1：1（Mg1.8）M0.2Ni-1.0 Ni） was further obtained by also the mechanical alloying. It is found that its amorphization and electrochemical properties were both significantly improved by the substitution and Ni coating. As to its cycle stability and high power discharge performance, the modified alloys are superior to the unmodified alloys. The initial discharge capacity of Mg1.8Ti0.2Ni-1.0 Ni and Mg1.8Zr0.2Ni-1.0 Ni reached 729.9 mAh·g-1 and 689.0 mAh·g-1, respectively, and was all greater than that of Mg2.0Ni-1.0 Ni alloy（665.5 mAh·g-1）. Among the modified alloys, Mg1.8Zr0.2Ni-1.0 Ni showed better cycle stability, and after the showed better cycle stability, and after the 100th-cycle, the discharge specific capacity remains about 400 mAh·g-1. The electrochemical properties of the modified alloys were further investigated by linear polarization, anodic polarization and electrochemical impedance measurement.

关 键 词：镁基储氢合金 机械合金化法 部分取代 包覆 电化学性能 

分 类 号：O646.21[理学—物理化学]