原位析出Li_3Bi对Li-Mg-N-H体系放氢动力学性能的影响

In situ formation of Li_3Bi and its improvement on the dehydrogenation kinetic property of Li-Mg-N-H system

基于对Li-Mg-N-H体系放氢动力学机理的研究发现,其放氢过程的速率控制步骤是Li+、H+或H-的扩散。在实验中,原位析出的Li3Bi相增加了Li-Mg-N-H体系放氢过程中Li+离子的扩散速率,进而使得该体系在200℃下放氢量(质量分数)从4.37%增加到4.55%,达到90%放氢量的放氢时间从298min缩短到11min。

Based on the understanding of dehydrogenation and hydrogenation reaction mechanism,the origin of kinetic barrier of the Li-Mg-N-H system is the mobility.In the experiment,the formation of Li3 Bi phase increases the diffusion rate of Li＋.The dehydrogenation capacity（mass fraction）is increased from 4.37%to 4.55%and the time required for 90% dehydrogenation is reduced from 298 min to around 11 min for the sample with 10% Bi（mass fraction）measured at 200 ℃.