Localized high-concentration electrolyte enabled by a novel ester diluent for lithium metal batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Achieving stable cycling of lithium metal anodes is crucial for high-energy-density batteries.
• High-voltage cathodes present challenges due to electrolyte instability and degradation.
• Developing advanced electrolytes is key to overcoming these limitations.

Purpose of the Study:

• To develop a novel electrolyte system for stable lithium metal anode cycling.
• To enhance the performance of lithium metal batteries with high-voltage cathodes.
• To investigate the effectiveness of ester diluents in localized high-concentration electrolytes (LHCEs).

Main Methods:

• Application of a novel ester diluent-based localized high-concentration electrolyte (LHCE).
• Evaluation of electrolyte oxidation resistance after dilution.
• Fabrication and testing of Li||Cu cells to assess Coulombic efficiency.
• Analysis of the solid electrolyte interphase (SEI) film for long-term stability.

Main Results:

• The ester diluent-based LHCE demonstrated retained oxidation resistance after dilution.
• Achieved over 99.5% Coulombic efficiency in Li||Cu cells.
• A robust SEI film was formed, enabling superior long-term operation.
• Successfully operated with a high-voltage cathode.

Conclusions:

• Ester diluents are effective in formulating localized high-concentration electrolytes (LHCEs).
• The developed LHCE strategy promotes stable lithium metal anode cycling.
• This approach is promising for advancing lithium metal battery technology with high-voltage cathodes.