基于放氢过程中形成三元金属硼化物的LiBH4多组元反应体系的构建、储氢性能及机理

LiBH4 has attracted rather more attention as a high-capacity hydrogen storage material. One important approach for improving the hydrogen storage properties of LiBH4 is to develop the multicomponent reactive systems. On the basis of our recent related studies, the present project starts from the construction of novel LiBH4 multicomponent reactive systems that allow the formation of the ternary metal borides during the dehydrogenation process, and contains four main research contents. Firstly, the formation condition and rule of the ternary metal borides will be studied, upon which the critical factors that affect the construction of novel LiBH4 multicomponent reactive systems will be revealed. Secondly, the efficacy of ternary metal borides formation on the improvement of hydrogen storage properties will be ascertained based on the systematical analysis of the de-/hydrogenation properties for the LiBH4 multicomponent reactive systems. The third task of this project is to explore the interaction and structure evolvement of components during the de-/hydrogenation process, and to clarify the de-/hydrogenation mechanism of the novel LiBH4 multicomponent reactive systems. Finally, the effect of ternary metal borides formation on the thermodynamic and kinetic characteristics of de-/hydrogenation of LiBH4 will be intensively investigated, and the micro-mechanism of hydrogen storage property improvement for the LiBH4 multicomponent reactive systems will be fundamentally revealed. In a word, the implementation of this project will provide the reliable theoretical basis and technical guidance for the optimization design and property improvement of LiBH4 and other metal borohydrides hydrogen storage materials.

LiBH4是目前广受关注的一种高容量储氢材料，多组元反应体系的构建是改善其储氢性能的重要途径。在申请人前期工作的基础上，本项目以能在放氢过程中形成三元金属硼化物的新型LiBH4多组元反应体系的构建为出发点，研究体系放氢过程中三元金属硼化物的形成条件和规律，揭示影响新型LiBH4多组元反应体系构建的关键因素；系统分析新型LiBH4多组元反应体系的吸放氢性能，查明并区分不同三元金属硼化物的形成改善LiBH4储氢性能的不同功效；探索新型LiBH4多组元反应体系吸放氢过程中的结构演变和组元之间的相互作用，揭示LiBH4多组元反应体系的吸放氢机制；深入研究三元金属硼化物的形成对LiBH4吸放氢热力学和动力学特性的影响，从根本上阐明LiBH4多组元反应体系储氢性能改善的微观机理。通过这些研究工作，为LiBH4和其它金属硼氢化物储氢材料的优化设计和综合性能改善提供理论依据和技术指导。

针对LiBH4多组元反应体系面向储氢应用存在的关键科学和基础问题，本项目在体系放氢过程中三元金属硼化物的形成条件和规律研究的基础上，构建了放氢过程中能形成MgNi2.5B2和MgAlB4的LiBH4/Mg-稀土-Ni氢化物和LiBH4/LiAlH4/MgF2、以及LiBH4/YbAl氢化物、LiBH4/LiAlH4/CaC2、LiBH4/稀土氟化物和LiBH4/SrF2等新型LiBH4多组元反应体系。借助LiBH4放/吸氢反应路径的调控和组元之间的协同催化作用，有效实现了体系可逆吸放氢性能的改善。探索了新型LiBH4多组元反应体系放/吸氢过程中的结构演变和组元之间的相互作用，揭示了体系的放/吸氢反应机制。研究了新型LiBH4多组元反应体系的放/吸氢热力学和动力学特性，查明了体系储氢性能改善的内在原因。通过这些研究工作，发表了学术论文8篇（其中SCI收录7篇），申请了国家发明专利9项（其中已授权3项），并为LiBH4和其它金属硼氢化物储氢材料的优化设计和综合性能改善提供了理论依据和技术指导。