用双辊快淬法制备了纳米晶稀土贮氢合金,XRD图谱表征为结晶较好的CaCu_5六方结构,Scherrer公式计算晶粒大小约为40nm.利用循环伏安法测定了纳米晶稀土贮氢合金电极中的氢扩散系数(DH=1.67×10~(-7)cm2/s),由于纳米晶粒具有较高的结晶度和细小的晶粒尺寸,高密度晶界为氢在合金内部的扩散提供快速通道,提高了贮氢合金的吸放氢效率,从而提高了氢的扩散性能,使电极中氢的扩散系数增大.
Nanocrystalline rare earth hydrogen storage alloy has been prepared by double-roller rapid quenching method.The alloy is of CuCa_5 hexagonal structure with crystal size about 40 nm determined by Scherrer formula. Cyclic voltammetry was used to determine the hydrogen diffusion coefficient(DH=1.67×10～(-7) cm~2/s) of the alloy. The nanocrystalline has high degree of crystallinity, small crystal particle size and high-density grain boundaries which provide a fast diffusion spread channel for hydrogen atoms to transport,and thus enhance the absorption and desorption of hydrogen.
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