锂离子电池三元层状正极材料LiNixCoyMnzO2（x+y+z=1）的高倍率充放电过程研究

项目名称： 锂离子电池三元层状正极材料LiNixCoyMnzO2（x+y+z=1）的高倍率充放电过程研究

项目编号： No.51502039

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 周永宁

作者单位： 复旦大学

项目金额： 21万元

中文摘要： 锂离子电池电极材料的倍率性能对于动力电池的应用至关重要。然而，目前国际上对于电极材料倍率性能的认识非常有限，尤其是在高倍率充放电过程中电极材料的变化情况。本项目拟通过固相反应法制备一组LiNixCoyMnzO2（x+y+z=1）三元层状正极材料。采用同步辐射X射线衍射谱，对它们进行不同倍率充放电过程中的原位结构表征（0.1C, 1C, 10C, 30C, 60C），研究其不同倍率条件下充放电过程中的晶体结构变化；采用电子显微镜技术，对不同倍率充放电过程中特定状态的样品进行微观结构形貌及原子排布的非原位表征。寻找结构变化与材料倍率性能之间的关系；探索层状正极材料高倍率充放电过程中容量衰减的机理；并研究高倍率充放电过程中静置（弛豫）过程对循环性能的影响。本项目的实施将有助于深入认识锂离子电池层状正极材料的高倍率充放电过程，为发展高倍率层状正极材料和设计可快速充电动力电池提供方向。

中文关键词： 锂离子电池；快速充电；倍率性能；原位表征

英文摘要： Rate capability of the electrode materials for lithium-ion batteries is crucial for the application of high power batteries in electric vehicles. However, the understanding about the rate capability of the electrode materials is quite limited, especially for the evolution of the materials during high-rate cycling. This project proposes to synthesize a group of layer structured LiNixCoyMnzO2 (x+y+z=1) cathode materials. By using synchrotron based X-ray diffraction technique, we are going to characterize the crystal structure change of the electrode materials in the real time during charge-discharge process at different C rate (0.1C, 1C, 10C, 30C, 60C). The local structure and atom arrangement of the samples at certain states during the charge-discharge process will be characterized by electron microscopy. The relationship between the structure changes and the rate capability will be investigated. The capacity fading mechanisms of the cathode materials during high-rate cycling will also be studied, as well as the impact of relax process on the cycle performance. The project will be quite helpful to the battery society to further understanding the high rate charge-discharge process of the battery materials. This will provide the guidance for developing layer structured cathode materials with better high rate capability and designing fast-charging enabled power batteries.

英文关键词： Lithium ion batteries;fast charging;rate capability;in-situ characterization