Yanghuan Zhang, Zhonghui Hou, Ying Cai, Feng Hu, Yan Qi, Dongliang Zhao
September 5, 2016
La–Mg–Ni–Mn-based AB 2 -type La 1– x Ce x MgNi 3.5 Mn 0.5 ( x = 0, 0.1, 0.2, 0.3, 0.4) alloys were fabricated by melt spinning. X-ray diffraction and scanning electron microscopy revealed that the experimental alloys consisted of a major phase LaMgNi 4 and a secondary phase LaNi 5 . The Ce substitution for La and melt spinning refined the grains of the alloys clearly. Electrochemical tests showed that the as-cast and as-spun alloys exhibited excellent activation capability. With the increase in the spinning rate and Ce content, the discharge capacities of the alloys initially increased and then decreased, whereas their cycle stabilities always increased. Moreover, the electrochemical kinetics of the alloys initially increased and then decreased with the growth of Ce content and spinning rate. The major reason leading to the capacity degradation of the alloy electrodes was determined to be the pulverisation of the alloy particles and the corrosion and oxidation of the alloy surface.