核壳结构纳米复合镁基储氢合金的制备及热力学调控机理研究

项目名称： 核壳结构纳米复合镁基储氢合金的制备及热力学调控机理研究

项目编号： No.51471070

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 王辉

作者单位： 华南理工大学

项目金额： 80万元

中文摘要： 如何利用纳米结构改善镁基合金的储氢性能并保持纳米结构和储氢性能的循环稳定性是解决镁基储氢合金实用化的关键问题。本项目提出利用核壳纳米结构中独特的界面和应力作用来调控镁基储氢合金的热力学性能。项目拟制备不同壳层材料、不同核/壳层尺寸的纳米镁基合金，准确表征核壳纳米复合镁基合金的微观结构、储氢热力学和动力学特性，揭示其吸/放氢反应机理；研究核壳界面结构的吸放氢特性及其对镁基合金储氢性能的影响；阐明核壳结构中应力的产生机制、微观结构影响因素（核层尺寸、壳层厚度、核壳界面等）及演变规律，全面揭示应力作用和界面特性对镁基合金吸/放氢平衡压、吸/放氢平台滞后、反应焓、反应熵等热力学参数的调控机理。本项目研究将为镁基储氢合金的热力学调控提供新的思路和理论指导，并为其它高容量储氢材料体系的热力学调控提供借鉴作用。

中文关键词： 储氢材料；镁基合金；核壳结构；纳米结构；储氢性能

英文摘要： The essential issue for improving the hydrogen storage properties of Mg-based alloys is how to reduce the dehydriding enthalpy by nanostructuring while keeping the structural stability of nanosized magnesium particles in the de-/hydrogenation cycles. The present project proposes a novel core-shell nanocomposite structure which could provide unique interface characteristic and stress regulation to alter the thermodynamics of magnesium hydride. The main research contents of this project include: the synthesis of core-shell nanostructured Mg-based hydrogen storage alloys with different shell materials, size and interface structure; The characterization and determination of microstructure and de-/hydriding kinetic and thermodynamic properties; The effect of shell materials on the core-shell interface structure and hydrogen storage performances; The de-/hydriding reaction mechanism of core-shell nanostructured Mg-based alloys; The hydriding and dehydriding characteristics of core-shell interface and its influence on the hydrogen sorption of magnesium based alloy; The formation mechanism of stress, the microstructure factors such as core size, shell thickness and core-shell interface, and the evolution of stress in the core-shell nanocomposite structure. The abovementioned study would elucidate the effects of interfacial stress on the thermodynamic properties, i.e. de-/hydriding equilibrium pressure,hydriding and dehydriding plateau hysteresis, reaction enthalpy, reaction entropy of Mg-based hydrogen storage alloys. The successful implementation of this project would open a new way to tune the thermodynamic properties of Mg-based hydrogen storage alloys, and promote the rapid development of other high-capacity hydrogen storage materials.

英文关键词： hydrogen storage materials;magnesium base alloy;core-shell structure;nanostructure;hydrogen storage properties