稀土储氢合金在高能效金属空气电池中的应用

使用水系电解质的金属空气电池具有理论储能密度高、材料成本低等优势，是极具前景的高性能电池。但Mg、Al等活泼金属在水溶液中不可避免会发生自腐蚀并析出氢气，不仅造成能量效率的巨大损失，也是巨大的安全隐患。本项目拟利用稀土储氢合金的可逆吸放氢性能，对金属水解产生的氢中间体进行调控，抑制析氢副反应，从而提高金属空气电池的能量效率。向金属空气电池的负极区引入储氢合金后，体系存在金属的直接氧化、储氢合金吸放氢、金属和储氢合金间氢和电子的转移等一系列相互耦合的过程。本项目将通过电化学原位光谱和质谱研究上述过程的动力学，阐明电化学过程中的氢电转移机制；进一步通过稀土储氢合金结构优化、表面改性以及电池各组件的整体优化，研制出全电池原理样机。本项目的实施不仅为高性能金属空气电池的研发提供了新的思路，对于拓展传统稀土储氢合金的功能，促进稀土资源均衡高效利用也有重要意义。

Metal air batteries using aqueous electrolytes are highly attractive due to their high theoretical energy storage density and low material cost. However, reactive metals such as magnesium or aluminum are subjected to inevitable hydrolysis reaction by forming hydrogen, which will cause severe loss of energy efficiency and also safety concerns. This project proposes to use the reversible hydrogen absorption/desorption properties of rare earth hydrogen storage alloys to inhibit H2 formation by controlling the hydrogen intermediate in the hydrolysis reaction, which will promote the energy generation efficiency of the metal air battery. After introducing rare earth hydrogen storage alloys into the anode chamber of metal air batteries, there exist coupled processes including direct oxidation of metal, hydrogen absorption/desorption of the hydrogen storage alloy and the electron and hydrogen transfer between the metal and the hydrogen storage alloy. In this project, we will develop in situ spectroscopy and mass spectroscopy approaches to study the above mechanisms in the operation of the battery, which, together with structure control and surface modification of the rare earth hydrogen storage alloy as well as optimization of the battery components, eventually lead to the development of a prototype full battery. This project will provide new insights into the development of high performance metal air batteries. It also extend the functionality of conventional rare earth hydrogen storage alloys, which is of critical importance for more balanced, value added utilization of the rare earth resources.