Tailoring Electrode-Electrolyte Interfaces via Electrolyte Additive Engineering for Reliable 5 V-Class 500 Wh Kg^-1...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Nonaqueous electrolytes in lithium metal batteries (LMBs) face challenges due to cathode incompatibility and flammability.
• High-voltage operation is hindered by surface parasitic reactions and dendrite growth.

Purpose of the Study:

• To develop functional electrolytes for stable and nonflammable high-voltage LMBs.
• To investigate the role of 1,2-bis(bromoacetoxy)ethane (BBAE) additive in enhancing electrolyte performance and safety.

Main Methods:

• Design of functional carbonate-based electrolytes with BBAE additive.
• Experimental characterization and theoretical simulations of electrolyte behavior.
• Electrochemical testing of LMBs with various high-voltage cathodes (e.g., NCM90, LiCoO2).

Main Results:

• BBAE addition resulted in nonflammable electrolytes enabling 5.0 V cell operation.
• In situ formation of reinforced hybrid halide electrode-electrolyte interphases (EEIs) suppressed parasitic reactions and dendrite growth.
• Optimized electrolytes demonstrated enhanced fire retardancy and wide-temperature tolerance.

Conclusions:

• The BBAE additive provides a straightforward strategy for stabilizing high-voltage LMBs.
• Reinforced EEIs and improved electrolyte flame retardancy are key to safe and durable LMBs.
• This approach facilitates the practical application of high-energy-density lithium metal batteries.