Underlying Mechanism of Electrolyte Compositional Engineering Based on Additive Solvation-Structure Governing Solid...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Optimizing additive dosage is crucial for solid electrolyte interphase (SEI) formation in lithium-ion batteries (LIBs).
• Understanding additive decomposition and its influence on SEI properties is key to improving battery performance and longevity.

Purpose of the Study:

• To investigate how the lithium-ion solvation nature of electrolyte additives influences SEI formation in LIBs.
• To determine the relationship between additive dosage and SEI reinforcement based on solvation characteristics.
• To propose a more effective approach to electrolyte engineering for LIBs.

Main Methods:

• Analysis of additive decomposition characteristics based on lithium-ion solvation.
• Observation of additive migration to the negative electrode during SEI formation.
• Correlation of additive dosage with SEI reinforcement for varying solvation strengths.

Main Results:

• Additives with strong lithium-ion solvation spontaneously migrate to the negative electrode, enabling SEI reinforcement through increased dosage.
• Weaker solvating additives lead to population-based SEI formation, where dosage-dependent modification is ineffective.
• Additive solvation properties significantly control SEI formation and reinforcement.

Conclusions:

• Electrolyte compositional engineering guided by additive solvation properties offers a more effective strategy than traditional trial-and-error methods for LIB optimization.
• Tailoring additives based on their lithium-ion solvation capabilities can precisely control SEI formation and enhance battery performance.
• This research provides a fundamental understanding for designing advanced electrolytes for next-generation lithium-ion batteries.