High-Voltage Lithium-Metal Batteries Enabled by Localized High-Concentration Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable lithium-metal batteries (LMBs) offer high energy density but face challenges with electrolyte stability against lithium anodes and high-voltage cathodes.
• Developing stable electrolytes is crucial for advancing LMB technology towards practical applications.

Purpose of the Study:

• To introduce a novel "localized high-concentration electrolyte" (HCE) for stable and efficient lithium-metal battery operation.
• To demonstrate the performance benefits of this new electrolyte in Li||LiNi1/3Mn1/3Co1/3O2 batteries.

Main Methods:

• Formulation of a localized HCE using 1.2 m lithium bis(fluorosulfonyl)imide in a dimethyl carbonate/bis(2,2,2-trifluoroethyl) ether mixture (1:2 mol ratio).
• Electrochemical testing of Li||LiNi1/3Mn1/3Co1/3O2 cells to evaluate cycling stability, Coulombic efficiency, and capacity retention.

Main Results:

• Achieved dendrite-free cycling of lithium-metal anodes with high Coulombic efficiency (99.5%).
• Demonstrated excellent capacity retention (>80% after 700 cycles) in Li||LiNi1/3Mn1/3Co1/3O2 batteries.
• The developed HCE exhibits low concentration, low cost, low viscosity, improved conductivity, and good wettability.

Conclusions:

• The novel localized HCE significantly enhances the performance and stability of lithium-metal batteries.
• This electrolyte design offers a promising pathway for practical, high-performance energy storage solutions.
• The localized HCE concept is applicable to various electrochemical systems, including sensors and supercapacitors.