分级结构的纳米晶磷酸铁锂微球的脱嵌锂机制及其比较研究

项目名称： 分级结构的纳米晶磷酸铁锂微球的脱嵌锂机制及其比较研究

项目编号： No.51504196

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 矿业工程

项目作者： 吴怡芳

作者单位： 西北有色金属研究院

项目金额： 22万元

中文摘要： LiFePO4是极具潜力的锂离子电池正极材料。而分级结构的纳米晶LiFePO4微球既能保持微米材料较高的振实密度，又具有纳米材料优异的锂离子迁移速率，是目前国内外锂离子电池领域的一个新兴热门课题。本项目通过化学还原共沉淀法制备分级结构的纳米晶LiFePO4微球，通过对电化学脱/嵌锂样品的晶体结构和微观缺陷结构特性的深入研究，结合电化学性能测试和电极动力学参数的表征，从微观、介观和宏观三个层次阐明了锂离子脱嵌过程中的相转变动力学和脱嵌锂机制。本项目的完成不仅可以推进分级结构的纳米晶LiFePO4微球的产业化进程，而且也有助于为长期处于争论状态的脱嵌锂机制的研究提供丰富的理论和实验依据。

中文关键词： 磷酸铁锂；分级结构；脱嵌锂；动力学

英文摘要： LiFePO4 is one of the most potential material as cathode for lithium ion batteries. The hierarchical nano-grain LiFePO4/C microspheres consisting of primary nano-grains exhibit both high Li-ion diffusion rate and a high tap density. The organization of nanoscale building blocks into hierarchical architectures is of great interest for scientists all over the world in the field of lithium ion batteries. In this project, the hierarchical nano-grain LiFePO4 microspheres are prepared by a chemical co-precipitation method. Based on in-depth study of crystal structure and micro-defects for electrochemical Li-insertion/extraction samples, combined with evaluation of electrochemical performance and electrode kinetic parameters (lithium ion migration rate and electrical conductivity), we expect to clarify the transformation kinetics and mechanisms in the process of Li-insertion/extraction reaction from the level of micro- and mesoscopic systems to macroscopic systems. The completion of project can not only promote the industrialization of hierarchical nano-grain LiFePO4/C microspheres, but also help for the debate about the mechanism in Li-insertion/extraction process. It will provide a theoretical and experimental basis for further research in this respect.

英文关键词： LiFePO4;hierarchical structure;Li-insertion/extraction;kinetics