Selectively fluorinated aromatic lithium salts regulate the solvation structure and interfacial chemistry for all-solid-state batteries

Solid polymer electrolytes suffer from the polymer-dominated Li + solvation structure, causing unstable electrolyte/electrode interphases and deteriorated battery performance. Here, we design a class of selectively fluorinated aromatic lithium salts (SFALS) as single conducting lithium salts to regulate the solvation structure and interfacial chemistry for all-solid-state lithium metal batteries. By tuning the anionic structure, the Li + -polyether coupling is weakened, and the Li + -anion coordination is enhanced. The hydrogen bonding between the SFALS and polymer matrix induces a special “triad”-type solvation structure, which improves the electrolyte homogeneity and mechanical strength, and promotes the…