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

Although silicon is being researched as one of the most promising anode materials for future generation lithium-ion batteries owing to its greater theoretical capacity (3579 mAh g(-1)), its practical applicability is hampered by its worse rate properties and poor cycle performance. Herein, a silicon/graphite/amorphous carbon (Si/G/C) anode composite material has been successfully prepared by a facile spray-drying method followed by heating treatment, exhibiting excellent electrochemical performance compared with silicon/amorphous carbon (Si/C) in lithium-ion batteries. At 0.1 A g(-1), the Si/G/C sample exhibits a high initial discharge capacity of 1886 mAh g(-1), with a high initial coulombic efficiency of 90.18%, the composite can still deliver a high initial charge capacity of 800 mAh g(-1) at 2 A g(-1), and shows a superior cyclic and rate performance compared to the Si/C anode sample. This work provides a facile approach to synthesize Si/G/C composite for lithium-ion batteries and has proven that graphite replacing amorphous carbon can effectively improve the electrochemical performance, even using low-performance micrometer silicon and large size flake graphite.

Automated summary

A silicon/graphite/amorphous carbon (Si/G/C) composite material has been successfully synthesized through a facile spray-drying and heating treatment method, and it exhibits excellent electrochemical performance in lithium-ion batteries compared to a silicon/amorphous carbon (Si/C) sample. The Si/G/C composite shows higher initial discharge capacity, better cyclic and rate performance, demonstrating that graphite can effectively improve the electrochemical properties of silicon anode materials.