中文摘要：

采用机械球磨法制备LiBH4/Li3AlH6复合体系,通过TG/DSC/MS、XRD等方法对其储氢性能及机理进行研究,并对其放氢反应激活能进行计算。结果表明,LiBH4-Li3AlH6复合体系从室温加热到500℃条件下发生3步放氢反应：首先,Li3AlH6分解生成Al并放出氢;然后部分生成的Al与LiBH4发生反应放出氢气;最后,剩余的Al与LiH反应放出氢气。复合体系总的放氢量达到8.5%（质量分数,下同）,完全放氢后的复合物在8MPa和400℃条件下最大吸氢量达到4.9%。并对LiBH4-Li3AlH6复合体系放氢过程机理进行了分析。

英文摘要：

LiBH 4 /Li 3 AlH 6 hydrogen storage composite was prepared by ball-milling,and its hydrogen storage properties and mechanism were studied by TG/DSC/MS and XRD analysis.The activation energies of the dehydrogenation reactions were calculated.The experimental results show that LiBH 4-Li 3 AlH 6 composite dehydrogenates shows three reactions：（1） Li 3 AlH 6 decomposes with hydrogen desorption and formation of Al;（2） part of Al reacts with LBH 4 with hydrogen desorption;（3） Al reacts with LiH.The total hydrogen desorption capacity reaches 8.5 wt%.And the mechanism of hydrogen desorption process of LiBH 4-Li 3 AlH 6 composite was discussed.