柔性海绵金属纤维耦合淬火锂金属负极及其界面调控机制研究

设计制备高性能柔性金属锂负极是推动可穿戴锂硫电池产业化应用的关键问题之一。本项目利用淬火锂SEI膜调控技术，结合新型柔性轻质的海绵金属纤维载体，构建柔性海绵金属纤维/淬火锂金属一体化负极。系统研究合成工艺对柔性复合负极材料的微结构、组分、相结构、界面和SEI膜组分的影响关系，揭示海绵金属纤维生长机制及其毛细耦合吸附金属锂机理和雾化淬火SEI成膜机制。分析复合负极结构的物相组分和微结构对上述柔性负极及其锂硫电池电化学性能的影响规律。研究淬火锂SEI膜的力学稳定性及其界面电场分布和电极反应动力学，解析淬火对金属锂负极的性能强化机制。探索海绵金属纤维与淬火锂的界面连接方式和电荷分布规律，结合同步辐射、原位光谱等手段阐明海绵金属纤维与淬火SEI膜对锂枝晶生长的协同抑制效应。分析海绵金属纤维/淬火锂负极的界面结构演变和失效机制，为设计构建高性能的柔性锂硫电池负极提供有价值的理论基础和实验依据。

One of the key issues to promote the commercialization of high-performance wearable lithium sulfur batteries is to rationally design/fabricate advanced flexible lithium metal anodes. Based on these requirements, the proposed project aims at integrating quenched Li metal into novel flexible and light-weight sponge metal fibres to fabricate flexible sponge metal fibres/quenched Li metal anodes by a facile hydrothermal-quenching method. We will systematically study the effect of synthetic parameters and techniques on the microstructure, phase, component, interface and SEI composition of sponge metal fibres/quenched Li metal anodes. And then we address the growth mechanisms of sponge metal fibres and its capillary adsorption effect on molten Li metal as well as the SEI formation mechanism by spray quenching method. In addition, we intend to investigate the influence of electrode microstructures and phase composition on the electrochemical performance of sponge metal fibres/quenched Li metal anodes and their lithium sulfur batteries. The mechanical stability of quenched SEI and its interface charge distribution as well as electrode reaction kinetics will be investigated in detail, and then we address the enhancement effect on the electrochemical performance by quenching way. Additionally, we analyze the connection mode and charge distribution rule between sponge metal fibres and quenched Li metal. By means of synchrotron radiation and in situ spectroscopy, we will clarify the synergistic effect on the suppressed dendrite growth of Li between sponge metal fibres and quenched Li metal. Moreover, we will reveal the interface evolution rule and failure mechanism of flexible sponge metal fibres/quenched Li metal anodes. This project will provide valuable theoretical basis and experimental evidence for the development of high-performance anode materials for application in advanced flexible lithium sulfur batteries.