基于内短路式预锂化技术的锂离子电池负极反应界面设计及其作用机理研究

由于纳米化反应机制，硅基负极在首次充电时产生的过高容量损失导致其实用化发展缓慢，因而需要进行预锂化修饰。在此，内短路式预锂化技术被认为是促进硅基负极迈向商品电池的重要前提。然而，目前对该技术的反应机制研究较为缺失，尤其是金属锂/负极界面在预锂化过程中的结构演变与作用机制尚无报道。我们前期研究发现在预锂化反应过程中，负极反应界面的SEI膜生长和金属锂溶解行为会造成金属锂与负极的空间隔离，导致预锂化反应提前结束。因此，我们推测通过优化金属锂/负极反应界面可促进预锂化的进行。为证实这一假说，本课题拟采用基于金属锂膜的内短路式预锂化技术对负极进行处理，并通过比较法和科学推论法来研究不同反应环境下的界面结构演变行为。采用原子力显微镜、固体核磁共振波谱等表征手段，系统研究反应界面在预锂化过程中的结构演变规律以及作用机制，阐明涵盖界面演变因素的内短路式预锂化反应新机理，为该技术的发展提供详细理论指导。

Due to the nanocrystallization, the high capacity loss during the first charge of the Si anode leads to the slow development of its practical application, so it needs to carry out pre-lithiation modification. In this regard, the internal short-circuit pre-lithiation (ISCPL) technology is considered as an important prerequisite to promote the development of Si anode towards commercial batteries. However, the research on the reaction mechanism of this technology is relatively lacking, especially the structural evolution and action mechanism of lithium/anode interface in the process of pre-lithiation have not been reported. Our previous study found that in the process of ISCPL, the SEI film growth and lithium metal dissolution at the reaction interface would cause the spatial isolation of lithium metal and anode, leading to the premature end of pre-lithiation reaction. Therefore, we hypothesize that the ISCPL can be promoted by optimizing the lithium metal/anode interface. To confirm this hypothesis, this project intends to use the ISCPL technology based on lithium metal film to process the anode, and the evolution behavior of interface structure under different reaction environments is studied by comparison and scientific inference method. In order to provide a detailed theoretical guidance for the development of this technology, a new mechanism of ISCPL reaction covering the interface evolution factors is elucidated by using the in-situ atomic force microscopy and solid state NMR spectroscopy.