N-Rich Bilayer Solid Electrolyte Interphase toward Highly Reversible Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) face challenges from continuous lithium/electrolyte interfacial reactions and dendrite formation.
• These issues limit the practical application of high-energy-density LMBs.

Purpose of the Study:

• To design and investigate N-rich polymer-inorganic bilayers at the lithium/electrolyte interface.
• To enhance the stability and lifespan of lithium metal batteries.

Main Methods:

• Fabrication of N-rich polymer-inorganic bilayers using nitrate-rich electrolytes.
• Characterization of the interfacial layer and lithium deposition morphology.
• Electrochemical testing of Li|Li symmetric cells and Li|S cells.

Main Results:

• The inner Li3N layer promotes uniform Li+ deposition, while the outer polymer layer accommodates volume changes.
• Synergistic effects prevent dendrite formation, leading to dense, spherical lithium nuclei.
• Li|Li cells demonstrated stable cycling over 1000 hours; Li|S cells achieved 697.6 mAh g-1 over 150 cycles with 99% Coulombic efficiency.

Conclusions:

• N-rich polymer-inorganic bilayers effectively suppress interfacial reactions and dendrite growth in LMBs.
• The designed interface significantly improves lithium plating/stripping reversibility and battery performance.
• This approach offers a promising strategy for developing high-energy-density and long-lifespan LMBs.