Li-Mg-N-H储氢材料体系具有高储氢容量(5.6wt%)以及放氢热力学良好等优异性能，是目前最接近我国《能源技术革命创新行动计划》提出的目标要求的材料之一。但是存在吸放氢动力学性能差、放氢过程易释放NH3和循环稳定性差等缺点，阻碍其实际应用。KH及K基化合物是改善Li-Mg-N-H动力学性能最好的催化剂，LiBH4对调控其热力学性能作用显著，多孔炭兼具有优良的导热性能和阻止粉末材料颗粒长大作用，本项目在申请人前期工作的基础上，将KH(或K基卤化物)、LiBH4和多孔炭中两种或三种复合添加协同改性Li-Mg-N-H材料的吸放氢热力学、动力学和循环稳定性，研究改性Li-Mg-N-H的吸放氢机制，阐明KH（或K基卤化物）、LiBH4、多孔炭对Li-Mg-N-H材料储氢性能的协同改性作用机理；优化改性Li-Mg-N-H材料组成，为Li-Mg-N-H的实际应用奠定基础。

Li-Mg-N-H hydrogen storage system, which is prepared from (2LiNH2+MgH2) , shows excellent comprehensive hydrogen storage properties, for example, it possesses hydrogen storage capacity of 5.6wt%, and the calculated temperature for hydrogen desorption pressure of 1 atm is around 90℃. Therefore, it is one of potential hydrogen storage materials that almost meet the requirements of on-board applications. However, Li-Mg-N-H hydrogen storage system also has some drawbacks, such as poor hydrogen absorption/desorption kinetics, emission of NH3 during hydrogen desorption process, and bad hydrogen absorption/desorption cycling stability, thus frustrate its practical applications. KH and K-based compounds is excellent catalysts for improving the hydrogen absorption/desorption kinetic properties of Li-Mg-N-H. While LiBH4 shows eminent effects on enhancing the hydrogen absorption/desorption thermodynamic properties. Porous carbon has good thermal conductivity, and it also has the confinement effect on fine powder materials, thus prohibits the growth of particle size. Based on the previous study, in this project, we combine KH (or K-based compounds), LiBH4 and porous carbon to improve the hydrogen storage properties of Li-Mg-N-H, including the hydrogen absorption/desorption thermodynamic properties, kinetic properties and cycling properties. By systematically studying the hydrogen storage behavior of the modified Li-Mg-N-H, clarify the mechanism of the co-modification effects of KH (or K-based compounds), LiBH4 and porous carbon on Li-Mg-N-H. This work will provide a theoretical basis to further improve the comprehensive hydrogen storage performance of Li-Mg-N-H. The research content and research results of this project have a guiding role for the study of other hydrogen storage systems, and have important academic value and good application prospects.