Deciphering DSCl‐Assisted Solvation and Interfacial Dynamic Evolution for High‐Performance Lithium Batteries

Abstract Electrolyte engineering advances high‐energy‐density lithium metal batteries (LMBs) by regulating electrode‐electrolyte interphases (EEI) and Li⁺ solvation structures. However, a significant challenge remains in optimizing the inner Helmholtz plane (IHP) and constructing stable EEI simultaneously, as current strategies often neglect the IHP's critical role in governing ion transport and solvation dynamics. Here, dimethylsulfamoyl chloride (DSCl), an additive with unique molecular design is introduced to precisely modulates the IHP and fine‐tunes Li⁺ solvation, offering mechanistic insights into its impact on intermolecular and interfacial interactions between electrodes and electrolytes. Specifically, DSCl preferentially adsorbs onto electrode surfaces, modulating the IHP to create a low‐solvent‐coordination environment that promotes ion transport. This facilitates the formation of LiCl‐rich cathode‐electrolyte interphase with reduced Li⁺ desolvation barriers and improved Li⁺ diffusion, while at the anode it drives the development of layered and inorganic‐rich solid‐electrolyte interphase that reinforces both mechanical strength and ion conductivity. Accordingly, the Li/Li cells exhibit stable cycling for over 700 h at 0.5 mA cm⁻²/0.5 mAh cm⁻² and only 0.5 wt.% DSCl‐containing LMBs realize 4.3/4.6 V‐LiNi_0.8Co_0.1Mn_0.1O₂ outstanding cycling performance and excellent rate performance (even at 9C). These findings underscore DSCl's potential to regulate solvation and interphase stability, providing a promising strategy for advancing LMBs technology.