Functionalized Boron Nitride-Based Modification Layer as Ion Regulator Toward Stable Lithium Anode at High Current...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries face limitations in energy density.
• Lithium metal batteries offer higher energy density but suffer from lithium dendrite growth.
• Controlling lithium dendrite formation is crucial for practical applications.

Purpose of the Study:

• To develop a novel composite separator for lithium metal batteries.
• To inhibit the formation and spread of lithium dendrites.
• To enhance the cycling stability and performance of lithium metal batteries.

Main Methods:

• Fabrication of a composite separator with functionalized boron nitride nanosheet modification layer.
• Utilizing the separator's polar groups and nanoscale channels to regulate lithium-ion fluxes.
• Investigating the lithiophilic effect and shunting action for uniform lithium deposition.

Main Results:

• The composite separator effectively suppressed lithium dendrites.
• Li||Li symmetrical cells demonstrated stable cycling for 800 hours at high current densities (10 mA cm⁻²).
• LiFePO₄||Li full cells exhibited 82% capacity retention after 800 cycles.

Conclusions:

• The developed composite separator successfully regulates lithium-ion flux and promotes uniform lithium deposition.
• The synergistic effect of lithiophilic modification and shunting action effectively suppresses dendrite growth.
• This approach significantly enhances the long-term stability and performance of lithium metal batteries.