Realizing Fast Diffusion Kinetics Based on Three-Dimensional Ordered Macroporous Cu₉S₅@C for Potassium-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium-ion batteries (PIBs) are promising for large-scale energy storage due to abundant resources and similar mechanisms to lithium-ion batteries.
• The large size of potassium ions leads to slow reaction kinetics, limiting the performance of PIBs.
• Developing efficient anode materials is crucial for advancing PIB technology.

Purpose of the Study:

• To synthesize a novel anode material for high-performance potassium-ion batteries.
• To address the challenge of sluggish potassium-ion kinetics in PIBs.
• To enhance the rate capability and cycling stability of PIBs.

Main Methods:

• Fabrication of 3D ordered macroporous copper sulfide embedded in carbon (3DOM Cu9S5@C) using a sulfidation and ion exchange strategy.
• Utilized 3D ordered macroporous Zn-based metal-organic frameworks as precursors.
• Characterization of the material's structure and electrochemical performance as a PIB anode.

Main Results:

• The 3DOM Cu9S5@C composite exhibits an interconnected 3D ordered macroporous structure.
• This structure facilitates rapid transport of potassium ions and enhances electrode-electrolyte contact.
• Achieved a remarkable rate capacity of 170 mA h g-1 at 2.0 A g-1 and cycling stability of 316 mA h g-1 at 100 mA g-1 after 200 cycles.

Conclusions:

• The 3DOM Cu9S5@C composite is a highly effective anode material for potassium-ion batteries.
• The unique porous structure significantly improves ionic diffusion kinetics and electrochemical performance.
• This work presents a viable strategy for developing advanced electrode materials for high-performance PIBs.