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

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.