一种镁基贮氢合金长储性能退化规律研究

Study on the Degradation Rule of Long-term Storage Performance of Mg-Based Hydrogen Storage Alloy

为探究Al粉和新型镁基贮氢合金ABM-2长储性能退化特性,采用71℃加速老化法研究金属粉在50%RH和75%RH环境中燃烧热和最小点火能量随老化时间的变化规律。结果表明:Al粉在71℃、50%RH环境中老化3d,最小点火能量大于1000mJ,燃烧热降为0。ABM-2在71℃、50%RH和75%RH环境老化56d后,最小点火能量由老化前100mJ分别升高至200mJ和240mJ,燃烧热分别降低5.05%和8.64%。XRD和EDS分析表明,ABM-2中的MgH2缓慢氧化生成Mg(OH)_(2)是导致ABM-2燃烧性能持续降低的主要原因,ABM-2中的Al表面形成氧化层,阻隔活性铝与水汽接触,因而相比Al粉具有较高的贮存稳定性。

In order to explore the long-term storage performance degradation characteristics of Al powder and a new Mg-based hydrogen storage alloy ABM-2,the 71℃accelerated aging method was used to research the law of change with aging time of combustion heat and minimum ignition energy(MIE)in 50%RH and 75%RH environments.The results show that MIE is greater than 1000 mJ and combustion heat drops to 0 when Al powder is aged for three days in 71°C,50%RH.After ABM-2 is aged for 56 days at 71℃,50%RH and 75%RH,the MIE is increased from 100mJ before aging to 200mJ and 240mJ,respectively,and combustion heat is decreased by 5.05%and 8.64%,respectively.XRD and EDS tests show that the main reason to cause the continuous decline in the combustion performance of ABM-2 is the slow oxidation of MgH2 in ABM-2 to form Mg(OH)2.An oxide layer is produced on the surface of Al in ABM-2,which cut off the contact between activated Al with water vapor,so ABM-2 has higher storage stability compared with Al powder.