添加Si對(duì)Mg-Li合金儲(chǔ)氫性能的影響

添加Si對(duì)Mg-Li合金儲(chǔ)氫性能的影響Effect of Si addition on hydrogen storage performance of Mg-Li alloy

在氬氣保護(hù)下，采用熱處理并結(jié)合機(jī)械球磨合金化制備Mg90Li10+x%Si(x=0, 2, 5, 8(質(zhì)量分?jǐn)?shù)))合金儲(chǔ)氫材料，研究Si的添加對(duì)Mg-Li合金儲(chǔ)氫性能的影響。結(jié)果表明：Mg90Li10+x%Si(x=2, 5, 8)合金材料經(jīng)過熱處理和機(jī)械合金化后，Li容易擴(kuò)散進(jìn)入Mg晶格體內(nèi)形成Mg(Li)固溶體，Si與Mg結(jié)合生成Mg2Si，而Mg2Si不僅能改善Mg-Li合金的吸/放氫動(dòng)力學(xué)性能，而且還能提高M(jìn)g-Li合金的熱力學(xué)性能。Mg90Li10+x%Si(x=0, 2, 5, 8)合金的初始脫氫溫度從632 K(x=0)分別下降到了610 K(x=2)、598 K(x=5)和598K(x=8)；Mg-Li合金的脫氫表觀活化能為396.5 kJ/mol，而添加Si后，其分別下降了13.3 kJ/mol(x=2)、21.1 kJ/mol(x=5)和67.4kJ/mol(x=8)。

The Mg90Li10+x%Si(x=2, 5, 8 (mass fraction)) alloys hydrogen storage material were synthesized by heat treatment in combination with mechanical milling, and the Si effect on the hydrogen storage properties of Mg-Li alloys were studied. The results show that the Li atom diffuses easily into Mg matrix to Mg(Li) solid solution, and the Si element reacts with Mg element to form Mg2Si. It is clearly that the existence of Mg2Si can improve the hydrogen absorption/desorption kinetic properties and thermodynamic performance for Mg-Li alloys. For example, with the addition of Si, the initial hydrogen desorption temperature for the Mg90Li10+x%Si alloys decreases from 632 K(x=0) to 610 K(x=2), 598 K(x=5) and 598 K(x=8), respectively. The apparent activation energies for the Mg90Li10+x%Si (x=2, 5, 8) alloys are 13.3 kJ/mol(x=2), 21.1 kJ/mol(x=5) and 67.4 kJ/mol(x=8) lower than that of Mg-Li alloy.

全文下載：https://pan.baidu.com/s/1pLV3F4n