A 3D Framework with Li₃ N-Li₂ S Solid Electrolyte Interphase and Fast Ion Transfer Channels for a Stabilized...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes offer high theoretical capacity but suffer from dendrite growth and solid electrolyte interface (SEI) fracture due to high reactivity and volume expansion.
• Existing SEI layers are prone to mechanical failure, hindering the performance and safety of lithium metal batteries.

Purpose of the Study:

• To address dendrite growth and SEI fracture in lithium metal anodes.
• To develop an in situ artificial inorganic SEI layer for enhanced lithium metal battery performance.

Main Methods:

• Fabrication of porous graphene oxide films doped with sulfur and nitrogen (SNGO) to serve as a lithium host.
• In situ formation of an inorganic-rich SEI layer (lithium nitride and lithium sulfide) on the SNGO host.
• Utilized 3D printing to create microchannels for improved ion transport and thermal/stress distribution.
• Performed COMSOL simulations to analyze ion transfer pathways and battery performance.

Main Results:

• The SNGO film facilitated the in situ formation of a robust inorganic SEI layer, improving Li-ion transport and SEI mechanical strength.
• 3D-printed microchannels optimized ion transfer and homogenized heat and stress distribution.
• The assembled anode demonstrated low capacity fading (0.1% per cycle at 2 C) with a sulfur cathode.
• Achieved stable capacity at low negative/positive electrode ratios (<3) in Li-S batteries due to high lithium utilization.

Conclusions:

• The SNGO host with an in situ artificial inorganic SEI layer effectively mitigates dendrite growth and SEI fracture in lithium metal anodes.
• The integrated approach of SNGO doping and 3D-printed microchannels significantly enhances the cycling stability and lithium utilization in Li-S batteries.