3D Bismuth Anode with Synergistic Structural and Interfacial Optimization for High-Performance Sodium-Ion Capacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion capacitors (SICs) face kinetic mismatches between anodes and cathodes.
• Bismuth-based anodes offer low potential and high capacity but suffer from significant volume expansion.

Purpose of the Study:

• To develop a stable and high-performance anode material for SICs.
• To mitigate the volume expansion issue of bismuth anodes during cycling.

Main Methods:

• Synthesis of bismuth nanoparticles anchored on porous carbon (Bi@PCN) using liquid-phase and thermal reduction.
• Electrochemical testing of Bi@PCN as an anode in SICs.

Main Results:

• The Bi@PCN composite demonstrated excellent rate capability (50 A g⁻¹) and cycling stability over 10,000 cycles.
• The porous carbon framework effectively accommodated the volume expansion of bismuth during alloying.
• The Bi@PCN//AC SIC achieved high energy and power densities (118.16 Wh kg⁻¹ and 11,574.83 W kg⁻¹).

Conclusions:

• Bi@PCN is a promising high-rate anode material for advanced sodium-ion capacitors.
• Anchoring bismuth on porous carbon effectively addresses the volume expansion challenge.
• This approach enhances the stability and performance of alloy-based anodes for energy storage devices.