非晶Mg-Fe复合物的机械球磨制备及其电化学储氢特性

研究了机械球磨制备的(2Mg+Fe)+x%Ni(x=0, 50, 100, 200)复合物的微结构和电化学储氢性能. 结果表明, 不加镍粉时, 镁粉与铁粉混合物经120 h球磨后仍然为纯镁与纯铁两相组织, 其电化学放电容量不到20 mA·h/g. 而加入镍粉和提高球磨强度有助于Mg-Fe非晶的形成, 并使颗粒尺寸减小, 添加镍粉越多, Mg-Fe非晶化程度越高, 放电容量越大, 而组合钢球混合球磨的粉末比等径钢球球磨的非晶化程度更高, 颗粒也更加细小均匀. 在x=100时, 不同尺寸和等径钢球球磨120 h合成的Mg₂Fe非晶复合物的最大放电容量分别达到542.0和455.3 mA·h/g.

Mechanical Ball Milling Preparation and Electrochemical Hydrogen Storage Properties of Amorphous Mg-Fe Composites

The microstructure and electrochemical properties of (2Mg+Fe)+x%Ni(mass fraction)  composites(x=0, 50, 100, 200) prepared by using the ball milling method have been investigated. The results show that there are still Mg and Fe single phase for the nickel-free mixtures of Mg and Fe powders milled for 120 h, and the discharge capacity of the nickel-free composite is less than 20 mA·h/g. However, increasing the Ni content and enhancing the milling power make it easy to form amorphous Mg-Fe structure and to reduce the crystal size. The Mg-Fe composites could reach higher amorphorization extent and the  better electrochemical properties with introducing more amount of Ni. Compared with the composites obtained by milling with the uniform balls, the composites milled with mixed balls have a higher amorphorization extent, much more homogeneous and smaller particle sizes. As x=100, the maximal discharge capacities of the composite milled for 120 h with the balls of  different sizes and the uniform balls are 542.0 and 455.3 mA·h/g, respectively.