钼基纳米多孔材料的可控构筑及储锂机制研究

As a key component in rechargeable lithium ion batteries, electrode materials play an important role in determining the electrochemical performance of the batteries. It is of particular importance to develop low-cost, high performance electrode materials. This project will focus on the design and fabrication of new porous molybdenum-based anode materials. New preparation strategies will be developed to manipulate the porous structures, dimension and crystallinity of these molybdenum-based materials. The phase, crystallinity and carbon content of the porous molybdenum-based materials will be well controlled through careful selection of the synthesis and post-treatment processes. The porous structure introduced will facilitate the penetration of the electrolyte with the electrode and shorten the diffusion distance of lithium ions and electrons. The surface coating is expected to enhance the lithium ion and electron conductivities of the molybdenum-based materials. Consequently, the rate capability and cycling stability of these materials will be improved. In situ characterization techniques, such as in situ X-ray diffraction and adsorption, will be employed to investigate the processes of lithium ion intercalation/de-intercalation to elucidate the energy storage mechanism for molybdenum-based materials and disclose the key factors that impact the performance of these materials. This research will develop new porous molybdenum-based materials with properties of high specific capacity, good rate capability, excellent cycleability and low cost, and will shed some new light on the mechanism of the reversible lithium ion storage in the molybdenum-based materials.

电极材料作为锂离子电池的重要组成部分，是提高锂离子电池性能的关键，也是制约锂离子电池发展的瓶颈。本项目拟以比容量高的钼基电极材料为研究对象，利用多孔结构有利于电极内部被电解液浸润，可以加快材料内部的传质过程这一特点，开发新的制备路线，设计合成出结构、形貌和晶相可控的新型钼基多孔电极材料。优化制备和后处理条件，控制多孔骨架材料的晶相、结晶度和碳含量；再对材料进行表面包覆等复合改性，改善锂离子的迁移率和导电性，从而进一步提高其电化学性能；以原位X-射线衍射和吸收等在线检测手段研究锂离子电池充放电过程，阐释钼基电极材料的储锂机理，为开发容量大、倍率特性好、循环稳定性高和成本低的锂离子电池电极材料进行积极探索。

新型电极材料开发是提高锂离子电池性能的关键，也是当前研究的一个热点。形貌和结构调控是提高材料性能的有效途径。钼基电极材料具有理论比容量高的优点，但是其结构和循环稳定性差，影响了其实际应用。本项目以钼基电极材料为研究对象，通过开发新的制备路线，设计合成出了结构、形貌和晶相可控的新型钼基多孔电极材料。多孔结构有利于电极内部电解液和锂离子的输运，加快材料内部的传质过程，并容纳充放电过程中钼基电极材料的体积变化，提高其倍率性能和结构稳定性；进一步通过表面包覆等复合改性改善材料的锂离子迁移率和导电性，从而提高电极材料的倍率性能；利用原位X-射线衍射和吸收等在线检测手段研究了锂离子电池充放电过程，阐释钒基电极材料的储锂机理。本课题研究为开发高性能锂离子电池电极材料进行了积极探索。项目实施过程中，在Adv. Funct. Mater. J. Power Sources等国际知名学术期刊上共发表SCI收录论文5篇和中文核心1篇，申请了1项国家发明专利。