新型KSi储氢合金的制备及性能研究

KSi alloy that composes of light elements has become one of the hotspots in the research of hydrogen storage materials. KSi alloy has high hydrogen storage capacity, low dehydrogenation temperature and good cycling stability and thus is considered to be one of the most promissing alloy for hydrogen storage. However, the developement and applications of KSi alloy are blocked by the difficulty of preparation of high-purity KSi alloy and the sluggish de-/hydrogenation kinetics. In view of the above mentioned problems, in this project, the high-purity KSi alloy is prepared by an improved method, so called "high pressure sintering plus self purification proceess". Moreover, we intend to develop a new synthetic method to prepare KSi alloy or KSiH3 under medium and low temperature.The hydrogen storage performances of prepared KSi alloy are systematically studied and the relation between hydrogen storage performances and material microstructures, such as phase structure and surface appearance, is investigated. To improve the sluggish kinetics, dopants or catalysts are doped into KSi alloy. After doping, the improved performances of KSi alloy are studied during hydrogenation and dehydrogenation and the catalyzing agents and the improvement mechanisms are discussed. The results of this project not only propel the utilization of KSi alloy, but also provide experimental basises for the development of hydrogen storage properties of other light alloys.

由轻质元素构成的KSi合金是储氢材料研究的热点之一。KSi合金具有较高的储氢容量，较低的吸/放氢温度和良好的循环稳定性，具有潜在的应用前景。但合金存在合成困难和吸/放动力学性能缓慢等问题，制约了其发展和应用。针对这些问题，本项目拟采用高压烧结辅以低压自提纯法制备高纯KSi合金，并探索一种在中低温合成KSi合金或其氢化物KSiH3的方法；系统地研究KSi合金的储氢性能，获得形貌和相结构等微观结构与储氢性能之间的关系；利用催化掺杂法来改善合金的动力学性能，揭示掺杂剂或催化剂在掺杂后所形成的催化活性组元，研究催化活性组元对合金储氢性能的影响，获得性能改善的作用机制。本项目获得的结果将推进KSi储氢合金的实用化进程，也为其它轻质储氢合金的储氢性能改善提供实验基础。

由轻质元素构成的KSi合金是储氢材料研究的热点之一。KSi合金具有较高的储氢容量，较低的吸/放氢温度和良好的循环稳定性，具有潜在的应用前景。但合金存在合成困难和吸/放动力学性能缓慢等问题，制约了其发展和应用。本项目通过高压烧结辅以低压自提纯法实现高纯KSi合金的制备，突破了KSi合金难以高纯度制备的难点；通过KH替代K实现KSiH3的中低温合成；表征了KSi合金的储氢性能，获得KSi合金吸放氢的热力学和动力学数据；通过催化掺杂和构建复合体系初步改善了KSi合金的储氢性能；提出了AB3型超点阵储氢合金的亚单元体积控制机制，有望用于指导新型超点阵储氢合金的开发。项目执行期间共发表标注本项目基金号的 SCI 收录论文14 篇，申请国家发明专利 3 项，获得国家发明专利1项，培养硕士研究生3名，博士研究生1名。圆满地完成了本项目规定的考核任务。