纳米化对Mg2Ni/MmNi5-x(CoAlMn)x复合储氢合金电极特性的影响

用高能球磨方法制备了Mg2Ni/MmNi5-x(CoAlMn) x复合储氢合金，并用化学镀对其进行包覆处理，X射线衍射（XRD）和扫描电镜（SEM)别证实复合合金具有团粒结构的特征，并在适当的球磨条件下达到纳米复合，本研究有模拟电池法分析了不同晶粒尺寸的单相和复合合金的电极特性，对于单相Mg2Ni和MmNi5-x(CoAlMn)x合金，球磨分别导致其放电容量增加加和降低，对纳米复合储氢合金而言，其放电容量并不是其组成合金的容理的简单加和，而是存在复合增强效应，当复合合金中组元相的晶尺寸小于100nm时，具有明显的复合增强效应。

ENHANCEMENT OF ELECTROCHEMICAL CHARACTERISTICS OF Mg2Ni/MmNi5-x(CoAlMn)x BY FORMING NANO-PHASE

Hydrogen storage composite was prepared by high energy ball milling of the mixture powder of Mg2 Ni and MmNi5-x(CoAlMn)x, alloys and subsequently wrapping with electroless plating. XRD and SEM analysis show that Mg2Ni/MmNi5-x(CoAlMn)x nano-phase composite has a mor- phology of particles composed of aggregate of constituent phases. The electrode properties of Mg2Ni alloy, MmNi5-x(CoAlMn)x alloy and nano-phase composite with different grain sizes were tested by the simulated battery test. It was found that the discharge capacity of Mg2 Ni alloy was obviously enhanced with increasing milling time, but vice verse for MmNi5-x(CoAlMn)x alloy. As to the nano phase composite, its discharge capacity was not simply the linear sum of the capacity of components constituted the composites. An enhancement effect on capacity has been observed in the nano-phase composite when the size of the phase inside composite is refined to less than 100 nm.