Dual Structure-Material Design of Separators toward Dendrite-Free Lithium Metal Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Lithium metal anodes are crucial for high-energy-density batteries but suffer from lithium dendrite formation, hindering practical applications.
• Lithium dendrites lead to short circuits and capacity fading, posing safety risks and limiting battery lifespan.

Purpose of the Study:

• To develop a novel separator for lithium metal anodes that suppresses dendrite growth.
• To enhance the stability and cycling performance of lithium metal batteries through rational separator design.

Main Methods:

• Fabrication of interconnected hollow porous polyacrylonitrile nanofibers (HPPANF) using a dual structure-material design strategy.
• Characterization of HPPANF separator's morphology, electrolyte uptake, ion conductivity, and performance in lithium metal batteries.
• Evaluation of lithium deposition behavior and cycling stability under high current density.

Main Results:

• The HPPANF separator exhibited interconnected mesopores facilitating high electrolyte uptake and ion conductivity.
• The separator's polar groups provided 3D ion channels, acting as a polymer-based solid-state electrolyte.
• Dendrite-free lithium deposition was achieved, leading to enhanced cycling stability of 1300 hours at 3 mA cm⁻².

Conclusions:

• The dual structure-material design of HPPANF separators effectively controls lithium ion flux, preventing dendrite formation.
• This rational separator design offers a promising strategy for stabilizing lithium metal anodes and improving battery performance.
• The HPPANF separator demonstrates potential for advancing next-generation high-energy-density batteries.