Multifunctional Cyclized Polyacrylonitrile (cPAN) as a Coating for Sb-Based Anodes in Sodium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Antimony (Sb) conversion electrodes offer high energy density for sodium-ion batteries (NIBs).
• Volume expansion during cycling causes mechanical instability, limiting Sb electrode performance.
• Conductive polymer binders (CPBs) can stabilize conversion materials, but their effects on ion insertion and surface chemistry are not well understood.

Purpose of the Study:

• To systematically investigate the impact of a cyclized-polyacrylonitrile (cPAN) layer on the sodium-ion (de)insertion chemistry of Sb-based conversion electrodes in NIBs.
• To elucidate the role of CPBs in enhancing the electrochemical performance of conversion electrode materials.

Main Methods:

• Electrochemical characterization techniques were employed.
• Systematic investigation of Sb-based electrodes with and without cPAN protective layers.

Main Results:

• The cPAN layer increased the achievable capacity of the Sb electrode system.
• The cPAN layer facilitated sodium-ion transport to the Sb active material.
• Charge transfer resistance of the electrode was reduced at early cycles by the cPAN layer.
• CPAN layer contributes to capacity through sodium ion storage.

Conclusions:

• A cPAN protective layer effectively enhances the performance of Sb-based conversion electrodes in NIBs.
• CPBs can improve sodium-ion battery performance by enhancing ion transport and electrode stability.
• Further research into CPB-electrode interactions is warranted for optimized energy storage solutions.