Uniform Li Deposition through the Graphene-Based Ion-Flux Regulator for High-Rate Li Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes offer high energy density but suffer from dendrite growth and low Coulombic efficiency.
• Polyolefin separators are modified with functional materials to enhance stability and prevent dendrite penetration.

Purpose of the Study:

• To develop a functional polymer separator using a graphene-based Li-ion flux regulator (GLR) to homogenize Li-ion flux and suppress lithium dendrites.
• To evaluate the performance of the GLR-modified separator in lithium metal batteries.

Main Methods:

• Surface modification of polypropylene separators with a graphene-based Li-ion flux regulator (GLR).
• Fabrication and testing of Li-Cu and Li-sulfur cells using the modified separators.
• Characterization of ion transport and electrochemical performance.

Main Results:

• The GLR-modified polypropylene separator (GLR-PP) effectively homogenized Li-ion flux and suppressed dendritic lithium growth.
• Li-Cu cells with GLR-PP showed superior cycle and rate performance compared to cells with a graphene-only modified separator.
• Li-sulfur cells with GLR-PP demonstrated highly stable cycling over 500 cycles.

Conclusions:

• Tailoring polymer separator surfaces with porous 2D materials like GLR is an effective strategy for improving Li metal battery performance.
• The GLR-PP separator enhances long-term cycle stability and electrochemical kinetics in Li metal-based batteries.