锂空气电池三维多孔非碳电极催化材料的设计构筑及性能研究

Li-air batteries with high theoretical energy density is a promising next-generation lithium battery technique. The operation in dried air without gas tanks can increase the whole energy density of the batteries and save the limited space in the electric vehicles. The key and challenge in the development of real Li-air are the design and fabrication of electrode catalysts with high CO2 reduction and evolution reaction activities. This project will develop novel method to construct three-dimensional porous non-carbon electrode catalyst materials from both the nano and molecule levels. The crystal structure, porous structure, electronic structure and the property of the interfaces with be tuned through the heteroatom-doping and surface modification during the synthesis and post-treatment processes. The CO2 reduction and evolution reaction activities are expected to be significantly improved. The relationship of the catalytic activities with the structure, composition, pore and interfacel property of the electrode catalysts will be systematically investigated. In situ characterization techniques, such as in situ X-ray diffraction and adsorption, and differential quantitative mass spectrometry, will be employed to investigate the electrode reaction processes to elucidate the energy storage mechanism for three-dimensional porous electrode catalysts and disclose the key factors that impact on the performance of these catalysts. This research will develop new three-dimensional porous electrode catalysts with properties of high specific capacity, good rate capability, excellent cycleability in pure CO2, and will shed some new light on the development of Li-air batteries operated in dried air.

具有高比能量的锂空气电池是极具应用前景的下一代锂电技术。开发在干燥空气中稳定循环的锂空气电池对于提升电池的整体能量密度、节省汽车内有限的空间具有重要意义，其关键和难点问题在于设计构筑出具有高二氧化碳还原和析出催化反应活性、可以在二氧化碳中稳定循环的高性能电极催化材料。本项目拟通过微纳米及分子层面的结构设计，构筑三维多孔结构非碳电极催化材料，对其进行杂原子掺杂和表面复合改性，调控材料的晶体结构、孔道结构、电子结构和表界面物理化学性质，提升材料的二氧化碳催化反应活性。系统地研究三维多孔电极催化材料的结构、组成、孔道和表面性质对传质过程、放电产物的沉积和分解、催化机制等的影响。利用原位X-射线衍射和吸收、差分电化学质谱等在线检测手段研究电池电极反应过程，阐释电池的储能机制，并在机理研究的基础上对其性能进行优化，为开发在干燥空气中稳定循环锂空气电池进行有益探索。

电极材料决定了电池的性能。本项目通过微纳米及分子层面的结构设计，构筑了三维多孔结构非碳电极催化材料，对其进行复合改性，调控材料的晶体结构、孔道结构、电子结构和表界面物理化学性质，提升材料的二氧化碳催化反应活性。系统地研究三维多孔电极催化材料的结构、组成、孔道和表面性质对传质过程、放电产物的沉积和分解、催化机制等的影响。所制备的具有三维结构的泡沫镍负载四氧化三钴-氧化镍（Co3O4-NiO）复合材料Co3O4-NiO@Ni，直接作为锂-氧气电池正极表现出非常优异的电化学性能，在100mA/g的电流密度下，放电比容量高达7905mAh/g；在截止容量为500mAh/g时，可以稳定循环120次，优于本项目的预期指标。提出了均相催化提升锂二氧化碳电池性能的新策略，首次将钌基配合物用作锂二氧化碳电池均相催化剂，延缓了最终产物碳酸锂的生成，有效降低了充电极化，实现了高效的锂二氧化碳电池电化学性能。在锂金属电池、锂硫电池、钠离子电池、锌离子电池电极材料方面也做一系列开创性工作。在Angew Chem., Nat. Commun., Energy Environ. Sci., ACS Nano, Energy Storage Materials, Adv. Sci.等国际知名学术期刊上共发表SCI 收录论文34篇，影响因子大于10的有21篇，申请并授权了4项国家发明专利。