LiBH4/Li3AlH6复合物的放氢性能与机理

Dehydrogenation Properties and Mechanism of LiBH4/Li3AlH6 Composite

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8 MPa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

Abstract:

LiBH4/Li3AlH6 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 LiBH4-Li3AlH6 composite dehydrogenates shows three reactions: (1) Li3AlH6 decomposes with hydrogen desorption and formation of Al; (2) part of Al reacts with LBH4 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 LiBH4-Li3AlH6 composite was discussed