Anions Tuned Solid Electrolyte Interphase in Lithium‐Ion Batteries

Abstract It is a key and challenging problem to study how the lithium salt anion affects the solid electrolyte interphase (SEI) film formation process. However, the current research focuses on the solvation structure of electrolytes with a general considered conclusion of the preferential reduction effect of anions, while the action mechanism of anions on the solvation structure is rarely studied. Herein, the specific role of anions in the SEI film formation process is illustrated by comparing the influence of anions on the solvation structure with two kinds of boron containing lithium salts. It is found that lithium salt anions can affect the coordination capability of lithium ions and solvents, and then affect the energy consumption in the desolvation process of lithium ions and the composition of SEI film. This work provides a method to study the film formation process, which have certain reference and guide significance for the research of electrolyte field.