倍率性能对锂离子电池在智能电网及电动汽车等领域的应用至关重要。决定磷酸铁锂及富锂层状氧化物等正极材料倍率性能的关键是材料中锂离子的迁移以及中心金属离子间的电子迁移。目前相关的电化学研究仍普遍采用传统固液界面的电极动力学模型，未考虑材料内部离子和电子迁移的耦合；实验上采用由大量活性材料颗粒构成的复杂电极，难以区分活性材料中的离子嵌脱与多孔电极内的离子传输。这不仅制约了对离子嵌脱微观机制和动力学的认识，也限制了动力学参数的准确获取。本项目基于纳微电极构建能准确研究上述正极材料本征离子嵌脱动力学的单颗粒和单“颗粒聚集体”电极；基于电荷（离子-电子）迁移建立锂离子嵌脱的微观动力学模型和单颗粒电极充放电宏观动力学模型，结合量子化学计算和有限元模拟，研究材料颗粒和颗粒聚集体的充放电行为；通过理论和实验结果对比印证，认识离子嵌脱微观机制，建立充放电动力学与材料物理及化学结构的关系，为材料的理性设计提供基础。

The power performance is crucially important for the applications of lithium ion batteries in smart grids and electric vehicles. The Li ion and electron transfer between the metal centers in intercalation materials such as LiFePO4 and LiNixMnyCozO2 is the key for the power performance of batteries. Currently, studies of charging/discharging behaviors of ion intercalation materials usually use electrodes with complicated compositions and structures, and the theoretical studies are generally based on the kinetic models for conventional solid-liquid electrochemical interfaces, which pay little attention on the electron/ion transfer processes in the active materials that are important for ion intercalation/de-intercalation. This severely inhibits the reliable determination of the intrinsic ion intercalation/de-intercalation properties of the battery materials. This project aims to tackle these problems by developing electrodes containing only a single particle and/or a single "particle aggregates" of ion intercalation/de-intercalation materials such as LiFePO4 and LiNixMnyCozO2, by utilizing the nano/micrometer-sized disk electrodes. This should allow accurate determination of the intrinsic ion intercalation/de-intercalation kinetics and its dependence on the particle composition and structures. In addition, we will develop microkinetic models to rationally describe the coupled electron and ion transfer in ion intercalation materials by combining quantum chemical calculation and contemporary charge transfer theories, and macroscopic dynamic models for charging/discharging behaviors of single particle electrodes. Through the combined experimental and theoretical results, we expect to establish the relationship between the charging/discharging dynamics of typical ion intercalation materials and their physical and chemical structure, which could provide a basis for rational design of battery materials.