掺杂镧系金属对氢化燃烧合成镁镍储氢合金的影响

Effect of Lanthanum Metals Doping on the Magnesium Nickel Hydrogen Storage Alloys Synthesized by Hydriding Combustion

借助于XRD,TG-DSC等技术研究了掺杂镧系金属对氢化燃烧合成镁镍储氢合金合成条件及合金性能的影响。结果表明:掺杂镧系金属的试样在氢气压力为2.0MPa,600℃下保温2h可大量形成Mg2NiH4;氢气压力越大,形成Mg2NiH4越多;过高的合成温度和过长的保温时间极不利于Mg2NiH4的形成;镧系金属的掺入使Mg2NiH4晶胞发生了一定的畸变;掺杂镧系金属的Mg2NiH4放氢温度为271.7℃左右,比未掺杂的降低了110℃左右;掺杂镧系金属试样的总放氢量可达3.21%(质量分数,下同);掺杂镧系金属的试样在300℃,0.1MPa下的放氢时间为7min^8min;活化可适当提高吸放氢量。

The effects of lanthanum metals doping on the synthesis of magnesium nickel hydrogen storage alloys synthesized by hydriding combustion were investigated through XRD, TG-DSC and SEM. The results indicate that a large number of magnesium nickel hydrides Mg2NiH4 can be synthesized at 600℃ for 2 hours by lanthanum metals doping. The increase of hydrogen pressure would form more Mg2NiH4, adversely, a higher synthesis temperature and a longer holding time would go against the formation of Mg2NiH4. The dehydriding temperature for the samples doped with Lanthanum metals is about 271.7℃, about 110℃ lower than that of undoped samples. For the samples doped with Lanthanum metals, the dehydriding amount is 3.21%, and dehydriding time is normally 7 minutes-8 minutes at 300℃, 0.1 MPa. It is found that the activation could improve the hydriding and dehydriding amounts.