Silicon/Graphite/Amorphous Carbon as Anode Materials for Lithium Secondary Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon anodes offer high theoretical capacity for lithium-ion batteries but suffer from poor rate capability and cycle stability.
• Existing silicon/carbon composites face challenges in optimizing performance for practical applications.

Purpose of the Study:

• To develop a novel silicon/graphite/amorphous carbon (Si/G/C) composite anode material.
• To enhance the electrochemical performance of silicon-based anodes for lithium-ion batteries.

Main Methods:

• Facile synthesis of Si/G/C composite via spray-drying followed by heat treatment.
• Electrochemical performance evaluation of Si/G/C and Si/C anodes in lithium-ion batteries.

Main Results:

• The Si/G/C composite achieved a high initial discharge capacity of 1886 mAh g^-1 at 0.1 A g^-1 with 90.18% initial coulombic efficiency.
• Si/G/C demonstrated superior cyclic and rate performance compared to Si/C, delivering 800 mAh g^-1 at 2 A g^-1.
• The study utilized micrometer silicon and large flake graphite, showing effectiveness even with lower-performance precursors.

Conclusions:

• Replacing amorphous carbon with graphite in silicon composites significantly improves electrochemical performance.
• The facile spray-drying method offers a scalable approach for synthesizing high-performance Si/G/C anodes.
• Si/G/C composites represent a promising anode material for advanced lithium-ion batteries.