Defect-Engineered Hexagonal Boron Nitride Enables Ionic Conduction for Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Lithium metal anodes face challenges with dendrite formation and interfacial instability, limiting their practical application.
• Hexagonal boron nitride (h-BN) is an electrically insulating material with potential for battery applications.

Purpose of the Study:

• To engineer defects in multiplayer h-BN to enhance ionic conductivity for lithium metal anodes.
• To demonstrate the effectiveness of defect-engineered h-BN in improving lithium metal anode stability and lithium-sulfur battery performance.

Main Methods:

• Multiplayer h-BN films were subjected to industrial-scale argon ion implantation to create controlled vacancy defects.
• Exfoliated h-BN flakes were integrated into a hybrid microfluidic-microelectronic chip for characterization.
• Cell-level demonstrations were performed using the engineered h-BN in lithium metal anodes and lithium-sulfur batteries.

Main Results:

• Controlled vacancy defects transformed h-BN into an efficient lithium-ion conductor while maintaining electrical insulation.
• Lithium metal anodes exhibited dendrite-free cycling with Coulombic efficiencies over 99.5% for 1000 cycles.
• Lithium-sulfur batteries with irradiated h-BN showed sustained specific capacity over 97% for 300 cycles, mitigating polysulfide shuttle.

Conclusions:

• Defect engineering of h-BN via argon ion irradiation is a scalable and robust route for creating efficient lithium-ion conductors.
• This approach significantly enhances the stability and performance of lithium metal anodes and lithium-sulfur batteries.
• The engineered h-BN provides a promising interface solution for next-generation high-performance batteries.