球磨La_2Mg_(17)+x%Ni(x=50,100,150,200)复合贮氢合金的电化学性能研究

Electrochemical Properties of Ball-Milled La_2Mg_(17)+x%Ni(x=50,100,150,200) Composite Hydrogen Storage Alloy

研究了球磨制备的La2Mg17+x%Ni(x=50,100,150,200)复合贮氢合金的电化学性能。XRD分析表明:随着Ni含量的增加,复合合金的晶体结构逐渐转变为非晶结构。电化学测试显示:球磨制备的La2Mg17+x%Ni复合贮氢合金在首次循环后即可达最大放电比容量,合金具有较好的活化性能;复合合金的放电比容量也随Ni粉加入量的增加而增大。在经过60 h球磨后制得的非晶态的La2Mg17+200%Ni复合贮氢合金,其303 K下放电比容量为353.1 mAh.g-1。电化学放电比容量的提高应归因于非晶结构的形成以及Ni粉对表面状态的改变。

The electrochemical properties of the ballmilled La2Mg17 ＋ x% Ni （x = 50, 100, 150, 200） composites hydrogen storage alloy were investigated. The XRD analysis showed that the crystal structure of the composite alloy gradually transformed into amorphous with the increase of Ni content. The electrochemical tests indicated that the composite alloy by ball milled could reach up to the maximum discharge capacity at their first cycle, and the alloys had good activation performance. The discharge capacity of the composite alloy increased with increasing amount of added Ni. After 60 h ball-milling, the La2Mg17 ＋ 200% Ni composite exhibited a high discharge capacity of 353. 1 mAh.g-1 at 303 K. The improvement of electrochemical discharge capacity was attributed to the formation of a homogeneous amorphous structure as well as the modification of the surface state after Ni addition.