双组元Mg-TM调制结构储氢薄膜的控制制备与储氢特性

Magnesium-based materials are promising reversible hydrogen storage materials with low-cost and high-capacity. However, thermodynamics of magnesium hydride are rather stable and kinetics of hydrogen desorption are slower. Alloying and microstructure control are the main methods to improve the hydrogen storage properties of magnesium-based alloys. We proposed to regulate its hydrogen storage performance via modulation structure with specific intragranular ordered structure. Hydrogen storage films of Mg-TM (Ti, Zr, Ni) with two-component structure will be prepared by spin-mask and semi-cosputtering method. Also the structural transformation behavior of Mg-TM- (H) Micro-mechanism will be studied. We will investigate the effects of anisotropic electron transfer caused by the Mg-TM binary structure on the thermodynamics and kinetics of hydrogen absorption and desorption; and the stability of the structure during the hydrogen absorption and desorption cycles. Meanwhile, the structure and hydrogen storage characteristics of the three-component Mg-TM-RE long-period ordered magnesium alloy were be also compared. This project will provide new structural control strategies for fully exploiting the effective hydrogen storage properties of Mg-based materials. The results of this project will help people understand the microscopic process of hydrogen absorption and desorption and phase transition of Mg-TM. This study plays a positive role in the development of magnesium-based novel hcydrogen storage materials, which has important academic significance and application reference value..

镁基材料是极具发展前景的低成本高容量可逆储氢材料。但氢化镁热力学较稳定、放氢动力学较缓慢。合金化和组织调控是改善镁基合金的储氢性能的主要方法。本项目提出了利用调制结构特有的晶内有序结构来调控其储氢性能。利用旋转掩膜结合半共溅射方法制备双组元调制结构Mg-TM(Ti,Zr,Ni)储氢薄膜，研究Mg-TM-(H)薄膜吸/放氢反应的结构转变行为及其微观机制。探索Mg-TM双组元调制结构引起的各向异性电子迁移对吸放氢转变的热力学与动力学影响，考察吸放氢循环中调制结构的稳定性。同时还与三组元Mg-TM-RE型长周期有序结构镁合金的结构与储氢特性相比较。本项目为充分挖掘镁基材料的有效储氢性能提供新的结构调控思路，研究结果有助于人们深入了解双组元调制结构Mg-TM的吸放氢相变的微观过程，对发展镁基新型结构储氢材料起到积极作用，因而具有重要的学术意义及应用参考价值。

本项目研究通过制备含调制结构的双组元Mg-TM储氢合金，利用其特有的晶内有序结构来调控储氢性能，以期改善镁基材料热力学较稳定、放氢动力学缓慢的缺点。本研究利用自行摸索的半共溅射方法制备双组元调制结构Mg-TM(Ti,Zr,Ni)储氢薄膜，研究Mg-TM-(H)薄膜吸/放氢反应的结构转变行为及其微观机制及其对吸放氢转变的热力学与动力学影响。研究结果开创性地实现了1）多晶与晶内调制结构复合结构。2）这种方法同步实现了储氢材料制备合金化、纳米化、催化、界面、应变控制。3）首次发现双组元调制结构储氢可逆化。4）其主要机制与应力应变、催化、调制结构中Mg-TM晶内异质界面和普通柱状晶界面相结合对合金薄膜储氢性能的重要影响有关。本项目的研究结果有助于人们深入了解调制结构对Mg-TM的吸放氢脱氢相变的微观过程细节，对研发新型镁基结构储氢合金起到启示与参考，同时也开发了一种简便易行的超晶格结构制备方法，因而具有重要的学术意义及应用参考价值。