Electrochemical reduction engineering for composite Sb/Cu₂Sb anodes toward high-efficiency potassium storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-capacity anode materials with long-term cycling stability are crucial for advancing potassium-ion batteries (PIBs).
• Antimony (Sb)-based materials show promise for high-energy PIBs but suffer from volume expansion and capacity decay.
• Existing anode materials face challenges in achieving both high capacity and durability for practical PIB applications.

Purpose of the Study:

• To develop a novel composite anode material for high-performance potassium-ion batteries (PIBs).
• To address the limitations of Sb-based anodes, specifically volume expansion and capacity fade.
• To establish a scalable method for creating advanced alloy/carbon composite anodes.

Main Methods:

• Controlled synthesis of a composite anode material (Sb/Cu₂Sb/NC) using a molten salt electrolytic method.
• Incorporation of electrochemically inactive Cu component to buffer lattice stress.
• Utilizing a nitrogen-doped carbon (NC) network to enhance conductivity and ion diffusion.

Main Results:

• The Sb/Cu₂Sb/NC anode delivered a high capacity of 348.6 mAh g^-1 after 100 cycles at 0.1 A g^-1.
• Excellent long-term cycling stability was observed, maintaining 192.9 mAh g^-1 after 1000 cycles at 1.0 A g^-1.
• An assembled Sb/Cu₂Sb/NC//PTCDA full cell showed a capacity of 134.3 mAh g^-1 after 300 cycles at 0.1 A g^-1.

Conclusions:

• The novel Sb/Cu₂Sb/NC composite is a promising anode material for high-performance PIBs.
• The molten salt electrochemical reduction method provides a scalable and versatile approach for next-generation anodes.
• The integrated design effectively mitigates volume expansion and enhances electrochemical performance in PIBs.