纳米组装和复合结构MgFe2O4负极材料合成及储锂性能研究

项目名称： 纳米组装和复合结构MgFe2O4负极材料合成及储锂性能研究

项目编号： No.21471049

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 尹艳红

作者单位： 河南师范大学

项目金额： 85万元

中文摘要： 发展高比容量、高循环稳定性的负极材料是锂离子电池研究的前沿课题之一。MFe2O4 (M = Ni, Cu, Co, Zn，Mg)系材料价格低且理论比容量高（大于1000 mAh/g），但由于锂化过程体积变化大、易团聚、导电性差，其稳定性和倍率性能较差，首次容量损失较大。纳米化材料虽可在一定程度上改善其稳定性，但效果有限。因此，本项目设计合成纳米MgFe2O4颗粒的组装结构（空/实心球、核壳）和复合结构（MgFe2O4/C或导电聚合物）。多孔组装结构可缓冲材料体积变化，有利于电解液渗透，提高离子扩散速率。复合结构可以提高材料导电性，减少与电解液的接触，提高首次效率，缓冲体积膨胀，从而改善其循环稳定性。拟采用凝胶浇注或水热法结合喷雾造粒技术制备多种结构MgFe2O4材料，研究其电化学性能及储锂机理，探讨其构效关系，为高比容量、循环稳定的新型MgFe2O4负极材料设计制备提供研究依据。

中文关键词： 锂离子电池；负极；MgFe2O4；复合材料；分级结构

英文摘要： Development of anode materials with high specific capacity, long cycling life has become one of the leading topics in the research field of li ion battery. MFe2O4 (M = Ni, Cu, Co, Zn，Mg) is cheap, with a theoretical capacity larger than 1000 mAh/g. Because of the large volume change during charge/discharge process, agglomeration, and low electronic conductivity, it exhibits unstable cycling performance, poor high rate capability and lower charge/discharge efficiency. Making nano material can improve the cycling stability to some extent, but that cannot solve all the problems. As a consequence, nano self-assembly (hollow/solid sphere) and composite structure (MgFe2O4/C or conducting polymer) MgFe2O4 material will be synthesized in this work. The porous assembly structure can release the volume change, accelerate the permeating of electrolyte and increase ionic diffusion rate. The composite structure can improve the electronic conductivity, reduce the contact between active material and electrolyte, increase the charge/discharge efficiency. In addition, the composite carbon or conducting polymer can act as a buffer to stabilize the structure, thus the cycling stability can be improved. Multiple structure MgFe2O4 will be synthesized using the gel-cast/hydrothermal and spray drying process. The electrochemical performance, lithium storage mechanics and structure-activity relationship will be studied. And a theoretical technical foundation for high specific capacity, long cycling life MgFe2O4 material will be established.

英文关键词： li-ion battery;anode;MgFe2O4;composite material;hierarchy