Metal-Free Polymer-Based Current Collector for High Energy Density Lithium-Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-metal batteries (LMBs) offer high energy density, but anode stability is crucial.
• Thin lithium anodes are prone to fragmentation, disrupting conductivity.
• Conventional copper current collectors are heavy and hinder uniform lithium plating.

Purpose of the Study:

• To develop a lightweight, metal-free current collector for LMBs.
• To improve the specific energy and cycle life of LMBs.
• To address limitations of traditional copper current collectors.

Main Methods:

• Fabrication of an ultra-light, 10 µm thick polymer-based current collector.
• Comparison of the specific mass of the polymer collector versus copper foil.
• Electrochemical testing of LMB cells with the novel current collector.

Main Results:

• The polymer current collector has a specific mass of 1.03 mg cm⁻², approximately 11% of copper foil.
• LMBs with the polymer collector achieved a specific energy of 448 Wh kg⁻¹, an 18% increase over copper-based cells.
• Enhanced cycle life was observed due to more homogeneous lithium deposition.

Conclusions:

• Metal-free polymer current collectors offer a viable alternative to copper for LMBs.
• This innovation significantly reduces battery mass and enhances energy density.
• The developed current collector promotes stable lithium plating, extending battery lifespan.