基于锂电池"石墨烯包覆Sn、Si基"负极体系的模拟计算与结构稳定新方法

项目名称： 基于锂电池"石墨烯包覆Sn、Si基"负极体系的模拟计算与结构稳定新方法

项目编号： No.11204090

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 赵灵智

作者单位： 华南师范大学

项目金额： 30万元

中文摘要： 采用模拟计算和实验制备相结合的方法，设计并优化石墨烯包覆体系中具有多相协同效应的三元锡合金、以及异相界面微结构吻合的硅表面修饰层物质，模拟并从电子结构层次阐明各物相的嵌锂机制，揭示各相嵌脱锂时的变化规律、协同效应及对体系比容量和结构稳定的贡献机制。主要内容有：(1)三元锡合金及硅修饰层的设计与计算方案；(2)各物相的物化特性及协同效应新机制；(3)分子设计所拟定物相的制备及控制方法；(4)石墨烯包覆前后界面微结构在深度循环时的变化规律及转变、失效机制；(5)电极过程和电池性能研究。本课题在阐明相关机理的同时，拟在探索多元/多相化合物的计算方案、改善复合电极结构稳定与循环特性的新方法、构建嵌脱锂的界面通道耦合模型方面取得突破。研究结果可为具有多相协同作用的、核壳结构式、高容量、长寿命复合负极的制备和应用提供理论依据，为今后同类材料设计提供计算方法与思路，也深化对锡/硅基负极电化学机理的认识。

中文关键词： 三元锡合金；硅修饰层；第一性原理计算；协同效应；核壳结构

英文摘要： By using the simulation calculation combining experimental approach，this project will design and optimize the ternary tin alloy with synergistic effect of multi-phases and the modified layer on Si surface with anastomotic microstructure mutually of heterophase boundary both in graphene-coated tin- and silicon-based anodes for lithium ion battery, simulate and elucidate from electron structure level lithium insertion mechanism of all phases, reveal the phases variation law, synergistic effect and contribution mechanism to the specific capacity and structural stability during lithium intercalation and de-intercalation. The main content of the project can be summarized as follows: (1) Design and calculation scheme of the ternary tin alloy and the modified layer on Si surface, (2) Physicochemical character of all phases and its new mechanism of synergistic effect, (3) Fabrication and control method of the phases from the molecular design, (4) Variation law and mechanism of convert and invalidation of heterophase boundary microstructure during deep charge/discharge cycles before and after graphene-coated the anodes, (5) Study of electrode process and battery performance. The project will not only provide some relevant mechanisms but also make breakthroughs about the calculation scheme of multicomponent and multiphase

英文关键词： Ternary tin alloy；Si-modified layer；The first-principle calculation；Synergistic effect；Core-shell structure