Hexachloro-1,3-butadiene as a Functional Additive for Constructing an Efficient Solid Electrolyte Interface Layer for...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Lithium (Li) metal anodes offer high energy density but suffer from dendrite growth and side reactions.
• Developing stable solid electrolyte interface (SEI) layers is crucial for practical Li metal batteries.

Purpose of the Study:

• To investigate hexachloro-1,3-butadiene (HCBD) as a functional additive for stabilizing Li metal anodes.
• To elucidate the mechanism of SEI formation and its impact on Li anode performance.

Main Methods:

• Density functional theory (DFT) calculations to predict HCBD-Li anode interactions.
• Electrochemical testing of Li||Li symmetrical cells with HCBD additive.
• Performance evaluation of LiFePO4-based cells using functionalized Li anodes.

Main Results:

• HCBD forms a LiCl-rich SEI layer with high ionic conductivity.
• The SEI layer promotes uniform Li+ deposition/stripping and suppresses side reactions.
• Li||Li symmetrical cells achieved 7000 h cycling lifespan with low hysteresis (10 mV).
• LiFePO4 cells showed improved cycling stability (141.1 mAh g-1 after 350 cycles at 1 C).

Conclusions:

• HCBD is an effective additive for stabilizing Li metal anodes.
• The HCBD-derived SEI layer significantly enhances battery performance and lifespan.
• This approach offers a promising strategy for next-generation high-energy-density batteries.