基于酚醛树脂的纳米结构金属氧化物/碳复合材料及其储锂性能研究

As a new type of anode material for lithium ion batteries, many transition metal oxides such as SnO2, Fe2O3, Co3O4, NiO, etc. have higher specific capacity compared with the traditional graphite-based material. However, the application of metal oxides is limited by the poor cycling performance, owing to the large volume effect during the charge-discharge process. Aiming at this problem, we propose a novel methodology to synthesize carbon nanocomposites with metal oxide nanowire arrays and three-dimensional networks, using mesoporous phenolic resin with two-dimensional hexagonal and gyroid cubic nanostructure as hard template. Based on the strategy of structure and composition control, the unique nanostructured metal oxide/carbon composites will provide higher Li+ diffusion ability and better withstanding of the huge volume change, which is favorable for the storage of lithium ion. In addition, the carbon matrix can be served as a conductive agent and cushion layer to relax the stress and protect the metal oxide from severe pulverization and agglomeration, leading to the enhanced reversible capacity with excellent cycling performance. This proposal will focus on the key problems such as the construction and component optimization of nanowire arrays and three-dimensional networks, study the general synthesis method of nanostructured metal oxide/carbon composites, explore the relationship between the composition, structure and electrochemical properties, and make a foundation for the application of new anode materials for lithium ion batteries.

作为一类新型锂离子电池负极材料，过渡金属氧化物（如SnO2、Fe2O3、Co3O4、NiO等）相比传统的石墨负极具有更高的比容量，但金属氧化物在充放电过程中体积效应严重、循环稳定性差，限制了其实际应用。针对以上问题，本项目围绕结构调整策略和组成调整策略，提出一种以六方柱状和双连续立方结构的介孔酚醛树脂为模板，制备金属氧化物纳米线阵列和三维网络结构/碳复合材料的方法，利用纳米结构金属氧化物优良的锂离子扩散能力、储锂能力、应力缓冲能力以及碳材料突出的导电性和软垫效应，有效降低锂离子电池负极材料的体积效应，防止材料粉化和团聚，提高电极可逆容量和循环稳定性。项目将针对纳米线阵列、三维网络结构的构建以及组分优化等关键问题，深入研究纳米结构金属氧化物/碳复合材料的普适性制备方法和组成-结构-性能关系，为新型锂离子电池负极材料的应用奠定基础。

作为一类新型锂离子电池负极材料，过渡金属氧化物（如SnO2、Fe2O3、Co3O4、NiO等）相比传统的石墨负极具有更高的比容量，但金属氧化物在充放电过程中体积效应严重、循环稳定性差，限制了其实际应用。针对以上问题，本项目围绕结构调整和组成调整策略，制备纳米结构金属氧化物/碳复合材料，利用纳米结构金属氧化物优良的锂离子扩散能力、储锂能力以及碳材料突出的导电性和软垫效应，有效降低锂离子电池负极材料的体积效应，防止材料粉化和团聚，提高电极可逆容量和循环稳定性。项目通过自组装技术、模板技术和静电纺丝技术，制备了一系列孔隙率高、导电性好的多孔碳/金属氧化物复合材料。研究表明纳米结构金属氧化物和多孔碳的协同作用使复合材料的稳定性显著提高，在100 mA g-1时循环充放电120次后，电容量最高可达789 mAh g-1。项目深入研究了金属氧化物/碳复合材料的组成、结构和储锂性能之间的关系，为提高金属氧化物负极材料的电化学性能提供了思路。