Hydrogen storage properties of as-cast and annealed low-Co La1.8Ti0.2MgNi8.9Co0.1 alloys  

作　　者：Wei-Qing Jiang Jin Guo Zheng-Cheng Zhou Yin-Yan Wei 

机构地区：[1]College of Physics Science and Technology,GuangxiUniversity,Nanning 530004,China [2]School of Basic Medical Sciences,Youjiang Medical Universityfor Nationalities,Baise 533000,China

出　　处：《Rare Metals》2016年第7期559-565,共7页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51071054 and51271061);the Natural Science Foundation of Guangxi(Nos.2010GXNSFD013004 and 2012GXNSFBA053149)

摘　　要：Low-Co Lal.8Ti0.2MgNi8.9Co0.1 alloys were prepared by magnetic levitation melting followed by annealing treatment. The effect of annealing on the hydrogen storage properties of the alloys was investigated systematically by X-ray diffraction （XRD）, pressure-com- position isotherm （PCI）, and electrochemical measure- ments. The results show that all samples contain LaNi5 and LaMg2Ni9 phases. LaCo5 phase appears at 1,000 ℃. The enthalpy change of all hydrides is close to -30.6 kJ.mo1-1 H2 of LaNi5 compound. Annealing not only increases hydrogen capacity and improves cycling stability but also decreases plateau pressure at 800 and 900 ℃. After annealing, the contraction of cell volume and the increase of hydride stability cause the high rate dischargeability to reduce slightly. The optimum alloy is found to be one annealed at 900 ℃, with its hydrogen capacity reaching up to 1.53 wt%, and discharge capacity remaining 225.1 mAh·g-1 after 140 charge-discharge cycles.Low-Co Lal.8Ti0.2MgNi8.9Co0.1 alloys were prepared by magnetic levitation melting followed by annealing treatment. The effect of annealing on the hydrogen storage properties of the alloys was investigated systematically by X-ray diffraction （XRD）, pressure-com- position isotherm （PCI）, and electrochemical measure- ments. The results show that all samples contain LaNi5 and LaMg2Ni9 phases. LaCo5 phase appears at 1,000 ℃. The enthalpy change of all hydrides is close to -30.6 kJ.mo1-1 H2 of LaNi5 compound. Annealing not only increases hydrogen capacity and improves cycling stability but also decreases plateau pressure at 800 and 900 ℃. After annealing, the contraction of cell volume and the increase of hydride stability cause the high rate dischargeability to reduce slightly. The optimum alloy is found to be one annealed at 900 ℃, with its hydrogen capacity reaching up to 1.53 wt%, and discharge capacity remaining 225.1 mAh·g-1 after 140 charge-discharge cycles.

关 键 词：La-Mg-Ni-based alloy Annealing treatment Hydrogen storage Electrochemical characterization 

分 类 号：TG139.7[一般工业技术—材料科学与工程] TG146.16[金属学及工艺—合金]