Application of Spectroscopic Techniques in the Development of Fast-Charging Lithium-Ion Batteries

Fast charging of lithium-ion batteries (LIBs) is now a critical challenge for the development of electric vehicles (EVs). The difficulty of achieving fast-charging LIBs arises from the sluggish Li-ion transport in both electrolytes and electrode materials and the sluggish charge transfer processes across the electrode–electrolyte interphases (EEIs). To overcome these obstacles, it is important to fully understand the transport mechanism of Li+ in electrode materials, electrolytes, and EEIs. Spectroscopic techniques are useful tools to detect the structural changes and reveal the mass transport mechanism during the cycling of the batteries, which are helpful to guide the design of novel electrode materials and electrolytes as well as optimal interphases for fast-charging batteries. In this paper, recent advancements in the application of spectroscopic techniques for the development of fast-charging LIBs are reviewed. We focus on the key roles of spectroscopic techniques in revealing the reasons for improved fast-charging capabilities of LIBs, including their application in the fields of electrolyte engineering, interphase modification, Li-plating detection, and composition/structure optimization. Moreover, the application of electrospectroscopic techniques in exploring the interfacial reactions of the electrodes is also discussed. Finally, some perspectives and research directions for improving spectroscopic techniques to advance the development of fast-charging LIBs are provided.