球磨时间对镁碳复合储氢材料结构和性能的影响

Effect of ball milling time on the structure and properties of Mg-C composites for hydrogen storage

采用氢气气氛中高能球磨反应法，制备了40Mg60C镁碳复合储氢材料，研究了球磨时间对材料粒度、晶体结构和放氢性能的影响。结果表明，球磨2h材料的粒度即可达纳米级，约10～20nm，球磨时间再延长，材料团聚程度加重；球磨2h的材料为纳米晶和非晶结构，当球磨时间增加到4h时，材料几乎成为非晶结构；球磨时间4h时，材料储氢量已趋于饱和，最大放氢量为3．15％（质量分数）；材料放氢温度随球磨时间的增加而降低，球磨5h材料的初始放氢温度和放氢峰温降为275．18和314．94℃。

The 40Mg60C composite for hydrogen storage was prepared by high-energy ball milling reaction with hydrogen. The effect of ball milling time on particle size, crystal structure and dehydriding property was researched. It was shown that the particle size of the composite reached about 10-20nm by ball milling for 2h,and the agglomeration phenomenon aggravated as milling time prolonging. Nanocrystal structure and amorphous structure coexisted in the material milled for 2h,while only amorphous structure existed in the material milled for 4h. The hydrogen storage of the material milled for 4h was saturated, which was up to 3.15wt%. The dehydriding temperature decreased as ball milling time prolonging,and the initial dehydriding temperature and the dehydriding peak temperature of the material milled for 5h were lowed down to 275.18 and 314.94 ℃ respectively.