FeSb₂ Nanoparticles Embedded in 3D Porous Carbon Framework: An Robust Anode Material for Potassium Storage with Long...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Antimony (Sb)-based materials are promising anodes for potassium ion batteries (PIBs) due to high capacity.
• However, large volume changes during cycling limit their stability.
• Developing stable Sb-based anodes is crucial for advancing PIBs.

Purpose of the Study:

• To design and synthesize an extremely stable anode material for PIBs using Sb-based compounds.
• To overcome the cycling stability limitations of Sb-based materials.
• To investigate the potassium storage mechanism and activation process of the new anode.

Main Methods:

• Synthesis of FeSb2 nanoparticles embedded in a 3D porous carbon framework (FeSb2@3DPC).
• Electrochemical characterization including galvanostatic cycling and ex situ analysis (XRD, TEM).
• Investigation of the synergistic effects of nano/porous structures and material composition.

Main Results:

• The FeSb2@3DPC composite achieved an ultra-long cycle life of over 4000 cycles at 500 mA g⁻¹.
• Ex situ studies revealed a gradual activation process for FeSb2 in potassium storage.
• Electrochemical polarization decreased, and capacitance-controlled charge storage became dominant after activation.

Conclusions:

• The FeSb2@3DPC composite exhibits excellent stability and long cycle life for PIBs.
• The nano/porous structure and inactive Fe contribute to enhanced performance.
• The material demonstrates a gradual activation mechanism, leading to improved potassium storage capability.