过渡金属氧化物(Co3O4、Fe2O3及NiO)晶面取向与锂离子迁移速率之间的构效关系研究

项目名称： 过渡金属氧化物(Co3O4、Fe2O3及NiO)晶面取向与锂离子迁移速率之间的构效关系研究

项目编号： No.21201177

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机化学

项目作者： 肖小玲

作者单位： 中国科学院大学

项目金额： 28万元

中文摘要： 过渡金属氧化物(Co3O4、Fe2O3及NiO)理论比容量远高于商品化碳负极材料，对于发展高比容量锂离子电池是一类很有潜力的负极材料，但这类负极材料的充放电速率也即倍率性能还有待于提高。电极材料的充放电速率主要取决于锂离子在材料中的迁移速率，一些电极材料具有锂离子迁移速率各向异性的规律，故暴露特定晶面能大大提高锂离子的迁移速率。本项目从锂离子迁移速率各向异性的特点出发，研究暴露不同晶面的Co3O4、Fe2O3及NiO倍率性能的差异，明确各种氧化物展示较好倍率性能的特定暴露晶面，以实现可控制备比容量更高、能快速充放电的负极材料Co3O4、Fe2O3及NiO。区别于传统的通过减小粒径或碳包覆来提高电极材料倍率性能的方法，本项目提出一种提高过渡金属氧化物倍率性能的新方法。同时构建Co3O4、Fe2O3及NiO晶面取向与锂离子迁移速率之间的构效关系，为提高其他电极材料的倍率性能提供借鉴与参考。

中文关键词： 过渡金属氧化物(Co3O4和Fe2O3)；晶面；锂离子迁移速率；电化学性能；构效关系

英文摘要： Transition metal oxides Co3O4, Fe2O3 and NiO, as anodes of lithium ion batteries, exhibit much higher capacities than that of graphite, which makes them very promising anode materials for developing lithium ion batteries with high capacity. However, the ralatively low rate capability of these oxides remain big challenge to be resolved. As we know, the rate capability of electrode materials mainly rely on the diffusion rate of lithium ion. Lithium ions show anisotropic diffusion rate in some electrode materials, which makes it possible that improving the rate capability by exposing specific crystal plane of the electrode materials. Within this proposal, we will first study the rate capability of Co3O4、Fe2O3 and NiO with exposing different crytal planes and find out which crystal plane works the best for fast Li+ transportantion. Then we will controlled synthesize the Co3O4、Fe2O3 and NiO with higher capacities and faster charge/discharge. Different from tranditional methods by decreasing material particle size and using carbon coating, a new method to improve the rate capability of transition metal oxides will be developed in this study. Furthermore, the stucture-activity relationship between crystal orientation of Co3O4、Fe2O3 and NiO and the diffusion rate of lithium ion will be constructed. Besides, our study

英文关键词： transition metal oxides (Co3O4 and Fe2O3)；crystal orientation；lithium diffusion；electrochemical properties；stucture-activity relationship