Novel Solid/Liquid Surface Electrochemistry Methods for a Safer Lithium-ion Battery: Dendrite and Dead Lithium Prevention

锂离子电池的安全性和快速充电的可能性主要受到石墨阳极镀锂的限制。了解电极-电解质界面动力学对石墨上锂枝晶形成的影响对锂离子电池的未来至关重要。近年来，人们观察到局部固体电解质间相（SEI）组成控制了锂的优先电镀，并证明了局部电化学表征的必要性。本研究旨在利用几种最先进的实验方法研究SEI上的电化学过程，以了解石墨表面基团如何与电解质分子相互作用，并促进锂和过渡金属的电沉积。目标是识别石墨上的金属镀层特征，并利用这些见解来提高电池安全性并实现快速充电。金属成核、生长和腐蚀将通过原位电化学扫描透射电子显微镜（ec-STEM）和扫描电化学显微镜（SECM）进行观察，以关联界面的结构和化学演变，并在同步加速器设施上使用高分辨率x射线显微镜（STXM）进行初步研究。研究局部电化学响应和表面动力学将有助于理解石墨表面与锂离子电解质之间的相互作用以及锂在石墨上的成核机制。该计划将使人们更好地了解锂离子电极上的金属电镀，并开发防止枝晶形成的新方法。此外，这项工作的见解将有助于实现更高能量和更可持续的金属电池。

Lithium-ion batteries' safety and the possibility of fast charging are mainly limited by lithium plating on the graphite anode. Understanding the impact of electrode-electrolyte interface dynamics on lithium dendrite formation on graphite is critical for the future of lithium-ion batteries. Recently, preferential lithium plating controlled by local solid electrolyte interphase (SEI) composition was observed, and the need for localised electrochemical characterisation was demonstrated.The proposed work aims to study the electrochemical processes on the SEI using several state-of-the-art experimental methods to understand how graphite surface groups interact with the electrolyte molecules and facilitate the electrodeposition of lithium and transition metals. The goal is to identify metal plating signatures on graphite and use the insights to improve battery safety and enable fast charging. Metal nucleation, growth and corrosion will be observed with in-situ electrochemical scanning transmission electron microscopy (ec-STEM) and scanning electrochemical microscope (SECM) to correlate the structural and chemical evolution of the interface and initial studies using very high-resolution x-ray microscopy (STXM) at a synchrotron facility. Looking into the localised electrochemical responses and surface dynamics will allow an understanding of the interplay between graphite surface and lithium-ion electrolyte and the lithium nucleation mechanism on graphite.The programme will result in a better understanding of metal electroplating on lithium-ion electrodes and develop new methods for preventing dendrite formation. Moreover, the insights from this work will facilitate the realisation of higher energy and more sustainable metal batteries.