Folded-hand silicon/carbon three-dimensional networks as a binder-free advanced anode for high-performance lithium-ion batteries

Abstract

Folded-hand silicon/carbon (Si/C) three-dimensional (3D) networks were fabricated by chemical vapor deposition coupled with ultrasonic atomization and successfully applied for a binder-free anode in lithium-ion batteries. The microstructure, morphology and electrochemical performance for Si/C 3D networks were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge tests. The repeated folded-hand units for Si/C composites are assembled into interconnected 3D networks. The folded-hand Si/C 3D networks show an outstanding charge capacity of 2277 mAh g−1 at 0.1 C, and still remain 2167 mAh g−1 after 100 cycles. They reveal an excellent rate capacity of 1848 mAh g−1 and capacity retention of 99% after 100 cycles at 2 C, the charge capacities of 862 mAh g−1 and capacity retention of 93% after 500 cycles at 5 C. The LiFePO4//Si-C full cell can maintain high capacity of 137 mAh g−1 and capacity retention of 92% after 500 cycles at 1 C rate. The superior electrochemical performance is attributed to the formation of three-dimensional folded-hand interconnected networks.