One-Step Synthesis of Multi-Core-Void@Shell Structured Silicon Anode for High-Performance Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Silicon anodes are promising for high-energy-density lithium-ion batteries but suffer from poor cycling stability.
• Existing core-void@shell architectures often use complex, environmentally unfriendly methods and have limited interfacial contact.
• Single-point van der Waals contact in traditional structures hinders efficient charge and mass transfer.

Purpose of the Study:

• To develop a facile, benign, one-step synthesis method for a novel multi-silicon-void@silicon dioxide (multi-Si-void@SiO2) anode structure.
• To investigate the electrochemical performance and cycling stability of the new anode material.
• To demonstrate the potential of this anode for commercial lithium-ion batteries.

Main Methods:

• One-step synthesis of multi-Si-void@SiO2 structures with abundant void spaces and multi-point chemical bonding.
• Fabrication of electrodes using the synthesized material.
• Electrochemical testing, including cycling stability at various current densities (0.1 A g⁻¹, 1.2 A g⁻¹, 2.0 A g⁻¹) and capacity retention analysis.

Main Results:

• The multi-Si-void@SiO2 anode exhibited highly stable cycling performance and excellent electrochemical properties.
• After 400 cycles (200 at 0.1 A g⁻¹ + 200 at 1.2 A g⁻¹), a specific capacity of 1440 mAh g⁻¹ was retained.
• A high specific capacity of 1182 mAh g⁻¹ was achieved even at a current density of 2.0 A g⁻¹.
• The anode demonstrated compatibility with various cathode materials used in lithium-ion batteries.

Conclusions:

• The developed multi-Si-void@SiO2 structure offers significant advantages over traditional architectures.
• The facile and benign synthesis method overcomes limitations of previous approaches.
• This anode material shows great promise for future commercial lithium-ion batteries requiring high energy and power density.