Mg+x%Mm(NiCoMnAl)_5复合储氢材料吸放氢性能研究

Hydriding Properties of Mg+x% Mm(NiCoMnAl)_5 Nano-/amorphous Composite Materials Prepared by Ball Milling

采用高能球磨法制备了Mg+x%Mm(NiCoMnAl)_5(x=10、20、30和40)纳米晶和非晶混合结构的复合储氢材料,并对其结构和吸放氢性能进行了研究．XRD结果表明,Mg与Mm(NiCoMnAl)_5球磨200h后有Mg_2Ni和La_2Mg_(17)相生成．吸氢动力学研究发现,在423K和3．4 MPa下,随着x增大,吸氢速率和最大吸氢量都出现了先增大后减小的趋势．当x=20时,复合材料的吸氢性能达到最佳,其最大吸氢速率达到0．45%/s,50s内即可吸氢3．6%．热重分析结果表明,Mg的氢化物相放氢温度降低到259℃(x=40)．

The Mg＋x% Mn（NiCoMnA1）s（x= 10、20、30 and 40） nano-/amorphous composite materials have been prepared by ball milling. Their microstructure and hydriding properties have been investigated. X-ray diffraction （XRD） results showed that La2Mg17 and Mg2Ni phases were formed after ball milling. The hydriding results showed that the addition of Mm （NiCoMnAl）s significantly improved the hydriding properties of Mg. The hydriding rate and the hydrogen capacity first increased and then decreased with the increase of the Mm（NiCoMnAl）5 content. When x was equal to 20, the composite material had the best hydriding performance. The maximum hydriding rate was 0.45 %/s and the hydriding capacity reached 3.6 within 50 s at 423 K and 3.4 MPa. TG analysis showed that the desorption temperature of magnesium hydrides was 259℃ when x was equal to 40.