物理化学学报 >> 2011, Vol. 27 >> Issue (02): 403-407.doi: 10.3866/PKU.WHXB20110206

电化学和新能源 上一篇    下一篇

LaMg8.40Ni2.34合金的相结构和储氢性能

李金华1, 刘宝忠1,3, 韩树民1,2, 扈琳2, 朱惜林2, 王明智1   

  1. 1. 燕山大学亚稳材料制备技术与科学国家重点实验室, 河北 秦皇岛 066004;
    2. 燕山大学环境与化学工程学院, 河北 秦皇岛 066004;
    3. 河南理工大学材料科学与工程学院, 河南 焦作 454000
  • 收稿日期:2010-10-20 修回日期:2010-11-16 发布日期:2011-01-25
  • 通讯作者: 韩树民 E-mail:hanshm@ysu.edu.cn
  • 基金资助:

    国家高技术研究发展计划(863)(2007AA05Z117), 国家自然科学基金(50971112, 51001043), 博士后科学基金(20100470990)和河北省自然科学基金(E2010001170)资助项目

Phase Structure and Hydrogen Storage Properties of LaMg8.40Ni2.34 Alloy

LI Jin-Hua1, LIU Bao-Zhong1,3, HAN Shu-Min1,2, HU Lin2, ZHU Xi-Lin2, WANG Ming-Zhi1   

  1. 1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China;
    2. College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China;
    3. School of Material Science and Engineering, Henan Polytechenical University, Jiaozuo 454000, Henan Province, P. R. China
  • Received:2010-10-20 Revised:2010-11-16 Published:2011-01-25
  • Contact: HAN Shu-Min E-mail:hanshm@ysu.edu.cn
  • Supported by:

    The project was supported by the National High-Tech Research and Development Program of China (863) (2007AA05Z117), National Natural Science Foundation of China (50971112, 51001043), China Postdoctoral Science Foundation (20100470990), and Natural Science Foundation of Hebei Province, China (E2010001170).

摘要:

利用真空感应熔炼和退火方法制备了LaMg8.40Ni2.34合金. 采用X射线衍射(XRD)分析、扫描电镜(SEM)和压力-组成-温度(PCT)测试仪测试了合金的相组成、微观形貌和储氢性能. LaMg8.40Ni2.34合金由La2Mg17、LaMg2Ni和Mg2Ni组成,且在第一次吸放氢循环中就可以完全活化. 在558 K下的可逆储氢量为3.01%(质量分数), 合金的PCT曲线表现出双吸氢平台, 分别对应着形成的MgH2和Mg2NiH4. 但是放氢曲线却只有一个平台出现, 这是由MgH2和Mg2NiH4之间的协同脱氢作用产生的. LaMg8.40Ni2.34合金在吸放氢时的活化能分别为(52.4±0.4)和(59.2±0.1) kJ·mol-1, 均低于Mg2Ni合金. 与纯Mg和Mg2Ni合金相比, LaMg8.40Ni2.34合金具有良好的活化性能、较高的储氢性能和优良的动力学性能.

关键词: 储氢材料, La-Mg-Ni合金, 压力-组成-温度曲线, 多相结构

Abstract:

The LaMg8.40Ni2.34 alloy was prepared by vacuum induction melting and subsequent heating treatment. The phase structure, morphology, and hydrogen storage properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and pressure-composition-temperature (PCT) measurements. The LaMg8.40Ni2.34 alloy was composed of La2Mg17, LaMg2Ni, and Mg2Ni phases. The alloy can be activated in the first hydriding/dehydriding process. Its reversible hydrogen storage capacity was 3.01% (mass fraction) at 558 K. PCT curves showed two hydriding plateaus corresponding to the formation of MgH2 and Mg2NiH4 and only one dehydriding plateau, which is due to the synergetic effect of hydrogen desorption between MgH2 and Mg2NiH4. The activation energy values of LaMg8.40Ni2.34 alloy were (52.4±0.4) and (59.2±0.1) kJ·mol-1 for the hydriding and dehydriding processes, respectively, and these were lower than that of the Mg2Ni alloy. The LaMg8.40Ni2.34 alloy exhibited good activation behavior, hydrogen adsorption and desorption reversibility, and kinetic properties.

Key words: Hydrogen storage material, La-Mg-Ni alloy, Pressure-composition-temperature curve, Multiphase structure

MSC2000: 

  • O642