Design Rules for Selecting Suitable Weakly Solvating Electrolytes for Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Weakly solvating electrolytes (WSE) are crucial for regulating Li+ solvation structures.
• Developing robust solid electrolyte interphase (SEI) layers is key for battery performance.
• Existing experimental methods for solvent characterization are often challenging.

Purpose of the Study:

• To establish a high-throughput computational workflow for identifying suitable solvents for WSE.
• To develop a novel descriptor (Ws) for screening potential WSE solvents.
• To validate the computational approach through experimental and simulation methods.

Main Methods:

• High-throughput calculation of Li+-solvent binding energy in stable conformations.
• Calculation of molecular polarity index (MPI) as an alternative to donor number and dielectric constants.
• Experimental verification, molecular dynamics (MD) simulations, and survival probability analysis.

Main Results:

• A workflow was developed and verified using 26 common solvent molecules.
• A new descriptor, Ws, was constructed based on binding energy and MPI.
• The Ws descriptor effectively screened solvents in 6 typical WSE systems.

Conclusions:

• The study presents a universal and efficient strategy for distinguishing potential solvents for WSE.
• The workflow can be adapted for other battery systems, accelerating materials discovery.
• This computational approach facilitates the design of advanced battery electrolytes.