Engineering High-Performance Li Metal Batteries through Dual-Gradient Porous Cu-CuZn Host

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Porous copper current collectors show potential for stabilizing lithium metal anodes (LMAs).
• Limitations include insufficient lithiophilicity of pure copper and limited porosity in 3D structures, hindering efficient composite preparation and performance.
• These issues lead to poor electrochemical performance in Li-Cu composite anodes.

Purpose of the Study:

• To develop a novel porous copper-copper-zinc (Cu-CuZn) host material for lithium metal anodes.
• To address the challenges of insufficient lithiophilicity and limited porosity in existing 3D porous copper structures.
• To enhance the preparation of Li-Cu composites and improve the electrochemical performance of Li-Cu composite anodes.

Main Methods:

• Fabrication of a dual-gradient porous Cu-CuZn (DG-CCZ) host architecture.
• Characterization of pore size distribution and gradient lithiophilic-lithiophobic properties.
• Electrochemical testing of Li half-cells, Li-Li symmetric cells, and Li-LFP full cells using the DG-CCZ host.

Main Results:

• The DG-CCZ host exhibits excellent capillary wettability to molten lithium and high porosity (66.05%).
• The gradient design promotes preferential interior lithium deposition, effectively suppressing lithium dendrite formation.
• Improved cycling stability was observed across all tested cell configurations.
• A pouch cell with a double-coated LiFePO4 cathode demonstrated a discharge capacity of 159.3 mAh g-1 at 1C.

Conclusions:

• The developed dual-gradient porous Cu-CuZn host significantly enhances lithium metal anode stability and electrochemical performance.
• This architecture effectively controls lithium deposition and inhibits dendrite growth, improving Li utilization efficiency.
• The study provides a promising strategy for designing advanced 3D lithium anodes for high-energy lithium metal batteries.