An In Situ Generated Organic/Inorganic Hybrid SEI Layer Enables Li Metal Anodes with Dendrite Suppression Ability,...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• High-quality solid electrolyte interphase (SEI) layers are crucial for suppressing lithium dendrite growth and enhancing the cycling stability of lithium metal batteries.
• Developing robust and efficient SEI layers remains a key challenge in advancing lithium metal battery technology.

Purpose of the Study:

• To construct a uniform and compact organic/inorganic hybrid SEI layer using 1-(6-bromohexanoyl)-3-butylurea (LiBr-HBU).
• To evaluate the performance enhancement of lithium metal batteries utilizing the novel LiBr-HBU SEI layer.

Main Methods:

• Synthesis of an organic/inorganic hybrid SEI layer (LiBr-HBU) using 1-(6-bromohexanoyl)-3-butylurea.
• Characterization of the LiBr-HBU SEI layer's structure, electrolyte wettability, air stability, and Li+ conductivity.
• Electrochemical testing of Li//Li symmetric cells and lithium-sulfur cells with and without the LiBr-HBU SEI layer.

Main Results:

• The LiBr-HBU SEI layer demonstrated a uniform, compact structure with superior electrolyte wettability and air stability.
• Achieved a Li+ conductivity of 2.75 × 10^-4 S cm^-1, approximately 50-fold higher than native SEI layers.
• Li//Li symmetric cells showed significantly improved cyclability (1333 h at 15 mA cm^-2), and lithium-sulfur cells exhibited enhanced rate capability (548 mAh g^-1 at 10 C) and cycling stability (513 mAh g^-1 at 0.5 C after 500 cycles).

Conclusions:

• The LiBr-HBU SEI layer effectively suppresses lithium dendrite growth and improves battery cycling stability.
• The developed artificial SEI layer offers a promising strategy for commercial processing of lithium metal anodes, protecting them against corrosion.
• This approach paves the way for next-generation high-performance lithium metal batteries.