锂电池用过渡金属基和石墨烯的片片相隔复合结构的设计合成和储锂机理研究

项目名称： 锂电池用过渡金属基和石墨烯的片片相隔复合结构的设计合成和储锂机理研究

项目编号： No.51271105

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 王勇

作者单位： 上海大学

项目金额： 80万元

中文摘要： 石墨烯和过渡金属基氧化物锂电池材料，由于具有较高的储锂容量，都被认为具有潜力替代商业碳负极。本项目设计了过渡金属氧化物纳米片分散在石墨烯纳米片上的片片相隔复合结构，针对性地解决两者仍存在的一些关键问题即：石墨烯极易团聚或堆积成为常规石墨片，失去其优异性能；金属氧化物的电导性较差，储锂时存在一定体积变化，导致储锂活性受到一定抑制。在设计的片片相隔复合结构中，两组分通过相似的纳米片结构的复合，能够最大程度地发挥协同功效,这是因为：二维的金属氧化物纳米片同石墨烯具有较大的接触或隔离面积，能够有效分隔石墨烯，防止其团聚；同时石墨烯也能通过片片紧密接触，有效缓解金属氧化物储锂时的体积变化和提高其电导性能。纳米片相对常见纳米粒子结构也更加稳定，不容易团聚。本项目将结合复合结构两种组分比例，形貌尺寸，复合匹配均匀程度等，达到储锂性能的优化，同时着重总结分析锂离子在该片片复合结构中插入、析出和储存的机理。

中文关键词： 石墨烯；金属氧化物；金属硫化物；锂电池；储锂机理

英文摘要： Graphene and transition metal oxides have been both suggested as promising andoe materials due to their high Li-ion storage capacities. This proposal designs new composies, namely the dispersion of transition metal oxides on graphene nanosheets (sheet-on-sheet composites), which aims to solve the current crucial problem with two component anodes. These problems are the heavy agglomeration of graphene materials, losing their intriguing properties; poor electrical conductivity of transition metal oxides; and partial pulverization and electrode cracking caused by the volume change of the metal oxide anodes during the repetitive cycling process with lithium ions, leading to a loss of electrical activity. In the proposed sheet-on-sheet composite, two components work together and exhibite complimentary synergistic effect. This is ascirbed to the following points: two dimensional transition metal oxides have large contact area with two dimensional graphene materials, leading to an effective separation of graphene nanosheets against further agglomeration. In addition, graphene materials are tightly stacked with transitional metal oxide nanosheets, therefore their volume changes or electrical conductivity can be accommodated or improved in the presence of graphene nanosheets.Compared to common nanoparticle, nanosheet st

英文关键词： graphene；metal oxide；metal sulfide；Li-ion battery；Li-storage mechanism