Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (02): 403-407.doi: 10.3866/PKU.WHXB20110206

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

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).

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