非晶态泡沫锂电极体系稳定固/固界面的构建及电荷跃迁动力学研究

Li metal is an ideal anode material for Li-ion batteries with a high theoretical capacity and the lowest electrode potential. However, the severe safety and stability problems significantly restrict its application. This project uses the (QJ)critical=AK2 equation as the guidance. Through studying high-conductive inorganic non-aqueous electrolyte, foam substrate with amorphous coating layer and preset elastic SEI film with high strength, the high-conductive inorganic non-aqueous electrolyte/highly elastic SEI film/amorphous Li foam electrode system can be achieved. In such an electrode system, the (QJ)critical constant of Li anode can be improved for 10,000 times to resolve the Li dendritic crystal problem caused by the slow Li+ transfer kinetics in SEI film, and both the polarized over-potential and Li surficial movement can be reduced for 100 times to avoid the nucleation of Li dendritic crystal and improve the interfacial stability of Li anode during cycling, which are proposed to resolve the safety and interfacial stability problems of Li anode. Moreover, studying the dynamic behavior of Li anode reaction and building the kinetic equation for charge transition in the interfacial region contained the “interfacial distance” parameter have important theoretical significant and academic value for the development of electrochemical basic science and innovative research for chemical power source.

金属锂具有很高的理论比容量和最负的电极电势，是理想的锂电池负极，但存在难以克服的安全性和循环稳定性问题，限制其应用。本项目提出三维泡沫锂电极体系的“临界QJ常数”公式：(QJ)临界=AK＾2作指导，并通过研究高电导率无机非水电解液、泡沫基体非晶态层修饰和预置高强度弹性SEI膜，实现构建高电导率安全电解液/预置高强度弹性SEI膜/非晶态泡沫锂电极体系的目标，可提高锂金属负极(QJ)临界常数4个数量级，能有效解决因Li+在SEI膜中传质速度慢所导致的锂枝晶问题，并可同时降低极化过电势和金属锂表面位移各2个数量级，对防止电结晶步骤锂枝晶成核和提高锂金属负极充放电循环过程中的界面稳定性具有重要作用，有望解决锂金属负极的安全性和界面稳定性问题。同时，研究锂金属电极反应的动力学行为，建立含“界面间距”参数的界面电荷跃迁动力学方程，对发展电化学基础理论和指导化学电源创新研究具有重要理论意义和和学术价值。

金属锂具有很高的理论比容量和最负的电极电势，是理想的锂电池负极，但存在难以 克服的安全性和循环稳定性问题，限制其应用。本工作针对高比能量金属锂负极提出了三维锂电极体系的“临界QJ常数”公式：(QJ)临界=AK＾2作指导，通过研究三维基体表面修饰、SO2基无机非水电解液和预置高强度弹性SEI膜，实现了构建三维基体预置高强度弹性SE I膜锂电极体系的目标，降低了锂金属电沉积的成核过电势，抑制了锂枝晶的生长，有效提高了锂金属负极充放电循环过程中的界面稳定性和金属锂负极的安全性，并分析了SEI膜与金属锂的固/固“界面间距”对电荷跃迁的影响，对防止电结晶步骤锂枝晶成核和提高锂金属负极充放电循环过程中的界面稳定性起到了重要作用。研究成果共发表负责人作为通讯作者SCI论文13篇，获负责人为第一发明人授权中国发明专利1项，具有一定的科学意义和潜在应用价值。