Multifunctional Electrolyte Additive Stabilizes Electrode-Electrolyte Interface Layers for High-Voltage Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium metal batteries (LMBs) offer high energy density but suffer from unstable electrode-electrolyte interfaces and cathode degradation.
• These issues lead to significant capacity decay, limiting the practical application of LMBs.

Purpose of the Study:

• To introduce N,O-bis(trimethylsilyl) trifluoro acetamide (BTA) as a multifunctional additive to enhance LMB performance.
• To investigate BTA's role in stabilizing electrode-electrolyte interfaces and mitigating cathode degradation.

Main Methods:

• Utilized BTA as an electrolyte additive in Li||NMC811 metal batteries.
• Analyzed the formation of solid electrolyte interphases (SEI) on anode and cathode surfaces.
• Evaluated electrochemical performance, including cycling stability and rate capability.

Main Results:

• BTA effectively removes trace water and hydrofluoric acid (HF), preventing interface disruption.
• BTA promotes the formation of LiF-rich, Si- and N-containing SEI films on both electrodes.
• The modified electrodes exhibit improved interfacial stability and reduced capacity decay.

Conclusions:

• The single BTA additive significantly enhances the electrochemical performance of LMBs.
• Demonstrated remarkable cycling and rate performance, with 162 mA h g⁻¹ after 100 cycles at 45 °C.
• Presents a cost-effective strategy for improving LMBs using a multifunctional additive.