Regulating Solvating Sites for Stable High-Voltage Lithium Metal Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• High-voltage lithium metal batteries (LMBs) require stable electrolytes for long-term performance.
• Increasing salt-to-solvent ratios can improve stability but faces solubility limitations.

Purpose of the Study:

• To develop a novel strategy for enhancing electrolyte stability in high-voltage LMBs.
• To improve the compatibility of electrolytes with lithium metal anodes and high-voltage cathodes.

Main Methods:

• Introduced a dual-anchoring strategy to regulate glyme solvation sites using directional atomic interactions (Fδ--Hδ+ and Hδ+-Oδ-).
• Investigated the impact of these interactions on Li+ coordination and glyme oxidation potential.
• Fabricated and tested lithium metal batteries with the modified electrolyte.

Main Results:

• Achieved an ultrahigh coulombic efficiency (CE) of 99.76% for lithium metal anodes (LMAs).
• Demonstrated extended battery lifespans: 834 cycles at 4.4 V and 370 cycles at 4.5 V for Li||NCM811 cells.
• Showcased 100 cycles in anode-free pouch cells, indicating excellent overall stability.

Conclusions:

• The dual-anchoring strategy effectively enhances the oxidative stability of ether-based electrolytes.
• This approach offers a promising pathway for advancing next-generation high-voltage lithium metal batteries.