一维富锂锰基正极材料介尺度结构演化过程机制及调控规律

项目名称： 一维富锂锰基正极材料介尺度结构演化过程机制及调控规律

项目编号： No.91534102

项目类型： 重大研究计划

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 张卫新

作者单位： 合肥工业大学

项目金额： 67万元

中文摘要： 为了满足电动汽车和电网储能等重大应用需求，研究开发具有更高能量密度和快速充放电能力的锂离子电池意义重大。富锂锰基正极材料因具有能量密度高、价格低、环境友好等优点而备受关注，但仍存在首次不可逆容量高、倍率性能与循环性能差等问题。本课题设计乙醇−水混合溶剂共沉淀反应，旨在通过引入乙醇溶剂改变晶粒成核生长的热力学与动力学过程，并结合后续煅烧反应过程调控制备一维介尺度结构富锂锰基正极材料xLi2MnO3·(l-x)LiMO2（M=Mn，Co，Ni等）。采用实验、计算和理论分析等研究手段，建立数学模型，揭示一维介尺度结构富锂锰基正极材料的形成、演化和控制机制，阐明反应和传质的协同作用对材料晶体结构、表/界面结构、形貌等介尺度结构和电化学性能的调控规律，为实现一维介尺度结构富锂锰基正极材料的规模化制备提供科学依据，也为富锂锰基正极材料应用于下一代锂离子动力电池奠定理论与实验基础。

中文关键词： 一维；富锂锰基正极材料；共沉淀反应；介尺度结构；模拟计算

英文摘要： It is of great importance to develop advanced lithium-ion batteries (LIBs) with high energy densities and rapid charge/discharge rates to meet the demands for next generation LIBs in electric vehicles and grid energy storage applications. Lithium-rich manganese-based cathode materials have received an upsurge of interest due to their high energy densities, low cost and environment benign for LIBs. However, these materials suffer from high initial irreversible capacity loss, poor rate capability and cycle performance. This project aims to clarify the process for preparing one dimentional (1D) lithium-rich manganese-based cathode materials xLi2MnO3·(l-x)LiMO2 (M=Mn, Co, Ni) with mesoscale structure based on co-precipitation in ethanol/water mixed solvent and followed by calcination. This strategy is based on adjusting thermodynamics and kinetics of the co-precipitation reaction for the crystallite nucleation and growth by introducing ethanol solvent. The formation, evolution and control mechanisms will be investigated through experiment, computation, modeling and theoretical analysis. This project will reveal the synergistic effects of both reaction and mass transfer on the mesoscale structures such as crystallite, surface/interface and morphology structures, correlated with electrochemical performances of the electrode materials. The research results will provide scientific basis for the large-scale production of 1D mesoscale structured lithium-rich manganese-based cathode materials based on the co-precipitation reaction in ethanol/water mixed solvent, and lay theoretical and experimental foundation for the application of lithium-rich manganese-based cathode materials in next generation power LIBs.

英文关键词： one dimension;lithium-rich manganese-based cathode material;co-precipitation reaction;mesoscale structure;simulation computation