快淬纳米晶和非晶Mg_(20)Ni_(10-x)Co_x(x=0～4)合金的贮氢性能(英文)

Hydrogen Storage Behaviour of Nanocrystalline and Amorphous Mg_(20)Ni_(10-x)Co_x(x=0～4) Alloys by Melt-Spinning

为了改善Mg2Ni型合金的贮氢性能,采用Co部分替代合金中的Ni以及快淬工艺制备了纳米晶和非晶态Mg20Ni10-xCox(x=0,1,2,3,4)贮氢合金。用XRD、SEM、HRTEM分析了铸态及快淬态合金的微观结构,并测试了合金的气态吸/放氢动力学及电化学贮氢性能。结果表明,在快淬无Co合金中没有形成非晶相,但快淬含Co合金中形成一定量的非晶相。Co替代Ni及快淬处理显著地改善了合金的气态吸放氢性能。同时,Co替代Ni也显著地提高了快淬态合金的放电容量和电化学循环稳定性。

In order to improve the hydriding and dehydriding behaviour of the Mg2Ni-type alloys,Ni in the alloy was partially substituted by Co,and melt-spinning technology was used to prepare the Mg20Ni10-xCox（x=0,1,2,3,4） hydrogen storage alloys.The structures of the as-cast and spun alloys were studied by XRD,SEM and HRTEM.The hydriding and dehydriding kinetics as well as the electrochemical performances of the alloys were measured.The results show that no amorphous phase is detected in the as-spun Co-free alloy,but the as-spun alloys substituted by Co display the presence of an amorphous phase.The substitution of Co for Ni and the melt spinning significantly improve the hydrogen absorption and desorption performances of the as-cast and spun alloys.Meanwhile,the substitution of Co for Ni enhances the discharge capacity and cycle stability of the as-spun alloys dramatically.