Li+/Li电对电化学氧化还原动力学行为研究

项目名称： Li+/Li电对电化学氧化还原动力学行为研究

项目编号： No.21473011

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 张存中

作者单位： 北京理工大学

项目金额： 40万元

中文摘要： 由于锂空气电池、锂硫电池有出色的高能量密度特点，近些年得到广泛关注和迅速发展。围绕这两种锂电池的安全性和循环效率，本申请将对电化学氧化还原过程中金属锂电极表面不均匀因素的发生、发展和锂离子在电解质中的传质行为以及它们之间的相互作用进行研究，重点是借助微电极/超微电极的独特优势(低的iR降、响应时间短、信噪比高等)对Li+/Li电对电化学氧化还原总过程进行解析，在各种电解质条件中得到Li+/Li电化学氧化还原总过程中各个基本步骤(锂离子传质、电荷转移、电化学结晶、金属锂腐蚀等)动力学行为特征及相关变化规律，阐明电解质的各种关键成分(溶剂、添加剂、支持盐、聚合物等)与各个基本动力学步骤的关系，将基本步骤的动力学行为与高倍率光学显微镜和扫描电镜现场观测结果进行结合，从复杂过程中基本步骤动力学行为的层面上阐明"锂枝晶"形成和生长、电极循环容量衰减的原因与机理。

中文关键词： 金属锂；二次电池；电极过程；电化学结晶；SEI膜

英文摘要： Due to the excellent energy density performance, lithium metallic-based batteries, Li-S battery and Li-air(O2) battery, have been focused extensively and developed rapidly in recent years. Based on the safety performance and redox cycle efficiency of lithium batteries, the non-uniform cases formed on the surface of lithium anode in redox cycle, mass transfer process and interaction among these non-uniform cases and mass transfer process will be investigated in this project. The total electrochemical redox process of Li+/Li couple is a complex and involves many element electrochemical steps and chemical steps. In this project, the element electrochemical steps, for example, mass transfer step, charge transfer step, electrochemical crystallization and corrosion, involved in total electrochemical redox process of Li+/Li couple will be investigated and explored by technique of ultra-microelectrode in different electrolytes condition ascribed to merits of technique of ultra-microelectrode, such as, low iR drop, short response time, higher S/N ratio. The relationships among important ingredients of electrolyte (solvent, support salt, additive agents, polymer et.al) and dynamic performance of element steps are also investigated for illumination of the reason and mechanism of main apparent problem, such as, formation of

英文关键词： lithium；secondary battery；electrode process kinetic；electro-crystallization；SEI