La_(1-x)Mg_xNi_(2.5)Co_(0.5)(x=0～0.4)储氢合金的制备及电化学氢化性能

Preparation and Electrochemical Hydrogenation Properties of La_(1-x)Mg_xNi_(2.5)Co_(0.5)(x=0～0.4)Hydrogen Storage Alloys

本文以感应熔炼法制备的La_(1-x)Mg_xNi_(2.5)Co_(0.5)(x=0~0.4)储氢合金作为研究对象,探究了熔炼过程中合金成分的损耗情况。通过对合金质量损耗的填补,并结合AES-ICP等测试手段,比较精确地制备出了目标合金。根据合金充放电前后的X射线衍射(XRD)测试结果,发现合金的氢化物随着Mg含量的增高而逐渐由非晶态转化成晶态,晶态氢化物由合金的α相转化成氢化物的β相。合金氢化物的晶胞参数a和c均显著增大,晶胞体积也有较大膨胀,但增大幅度却随着Mg含量的增加而逐渐减小。在0.1MPa干燥Ar保护条件下,填补0.9%的La和10.0%的Mg所制备的La_(0.7)Mg_(0.3)Ni_(2.5)Co_(0.5)合金不仅具有良好的电化学氢化性能和较大的放电容量,而且能够有效抑制合金的氢致非晶化。

The element loss during smelting of La1-xMgxNi2.5Co0.5（x=0-0.4）as hydrogen storage alloys by induction melting method was investigated.The target alloys were synthesized successfully by means of filling the mass loss combining with AES-ICP method.The hydrides of the alloys gradually transformed from amorphous to crystalline with increasing Mg content according to X-ray diffraction（XRD）for the alloys before and after charging and discharging.The cell parameters aand cof the alloy hydrides increased significantly,and the cell volumes also expanded considerably,but the increase extent decreased with increasing Mg content.In the condition of dry Ar gas under 0.1 MPa,the La0.7Mg0.3Ni2.5Co0.5 alloy prepared by filling 0.9% mass loss for La and 10% mass loss for Mg not only had agood electrochemical hydrogenation property and large discharge capacity,but also had an effective inhibition to the hydrogen-induced amorphization.