中文摘要：

采用真空感应熔炼技术制备了La_（2-x）Sm_xMg_（16）Ni（x=0,0.1,0.2,0.3,0.4）储氢合金。用X射线衍射（XRD）研究了合金吸放氢前后的相结构,用Sievert测试了合金吸放氢动力学曲线,采用Arrhenius法估算了合金吸放氢的活化能。结果表明,铸态合金的主相是La_2Mg_（17）,并存在少量的第二相SmNi和Sm_5Mg_（41）。合金吸氢后形成了氢化物LaH_3和MgH_2。合金的吸氢量、吸放氢动力学随Sm替代量的增加而增加,当Sm替代量从x=0增加到x=0.4时,最大吸氢量从4.458%（质量分数,下同）增加到4.925%。在3 MPa,498 K下,10 min的吸氢量分别为：4.308%,4.342%,4.488%,4.564%,4.787%;在真空、498 K下,20 min的放氢量分别为1.684%,1.521%,1.779%,1.666%,2.131%。Sm替代对合金吸放氢动力学性能的改善主要归因于Sm使合金的活化能降低。随着合金中Sm替代量的增加,合金生成焓ΔH的绝对值及吸氢平台压先减小后增加。制备合金中,La_（1.7_Sm_（0.3）Mg_（16）Ni合金的生成焓ΔH的绝对值最小,为-53.07 k J·mol-1。

英文摘要：

Hydrogen storage alloys of La2-xSmxMg16 Ni（x=0-0.4） were prepared by induction melting furnace. The alloy structure was analyzed by X-ray diffraction （XRD） before and after hydrogen absorption. The absorption/desorption hydrogen dynamics was investigated at different temperatures under pressure of 3 MPa. The activation energy of the alloy for absorption/desorp- tion hydrogen was counted by Arrhenius means. The results showed that the main phase of the alloy was La2Mg17 when La was partially replaced by Sm, and the second phase was SmNi and Sm5 Mg41. LaH3 and MgH2 phases were found in the ahoy after hydrogen absorp- tion. With increase of Sm content, the maximum absorption hydrogen storage capacity and the absorption/desorption hydrogen dynamics kinetics were increasing. The hydrogen absorption capacity was 4. 308% , 4. 342% , 4. 488% , 4. 564% , 4. 787% （ mass fraction, the same hereinafter） , at 3 MPa and 498 K within 10 min. However, the hydrogen desorption capacity was 1. 684% , 1. 521% , 1. 779% , 1. 666% , 2. 131% in vacuum and 498 K within 20 min. The absorption/desorption hydrogen dynamics of the alloy was improved be- cause Sm reduced the activation energy of the alloy. With the increase of Sm content in the alloy, the absolute value of formation en- thalpy （AH） and hydrogen absorption platform pressure decreased firstly and then increased. The AH of Lal.TSm0.3 Mg16Ni alloys was the minimum value in prepared alloys, which was -53.07 kJ .mol-1.