A study on hydrogen storage and electrochemical properties of La0.55Pr0.05Nd0.15Mg0.25Ni3.5 (Co0.5Al0.5)(x) (x=0.0, 0.1, 0.3, 0.5) alloys

作者：Qin Ming; Lan Zhiqiang; Ding Yang; Xiong Kai; Liu Yixin; Guo Jin^*

来源：Journal of Rare Earths, 2012, 30(3): 222-227.

DOI：10.1016/S1002-0721(12)60027-1

• hydrogen storage alloy
• hydrogen storage property
• electrochemistry property
• rare earths

The La0.55Pr0.05Nd0.15Mg0.25Ni3.5(Co0.5Al0.5)(x)(x=0.0, 0.1, 0.3, 0.5) alloys were prepared by magnetic levitation melting under an Ar atmosphere, and the effects of Co and Al on the hydrogen storage and electrochemical properties were systematically investigated by pressure composition isotherms, cyclic voltammetry, Tafel polarization and electrochemical impedance spectroscopy testing. The results showed that the alloy phases were mainly consisted of (La,Pr)(Ni,Co)(5), LaMg2Ni9, (La,Nd)(2)Ni-7 and LaNi3 phases, and the cell volumes of (La,Pr)(Ni,Co)(5), LaMg2Ni9, (La,Nd)(2)Ni-7 and LaNi3 phases expanded with Co and Al element added. The hydrogen storage capacity initially increased from 1.36 (x=0) to 1.47 wt.% (x=0.3) and then decreased to 1.22 wt.% (x=0.5). The discharge capacity retention and cycle stability of the alloy electrodes were improved with the increase of Co and Al contents. The La0.55Pr0.05Nd0.15Mg0.25Ni3.5(Co0.5Al0.5)(0.3) alloy electrode possessed better electrochemical kinetic characteristic.

• 出版日期2012-3
• 单位百色学院; 广西大学