Figure 5

Electrochemical characterization of different electrodes.

Voltage profiles of (a) CNS/Si and (b) CNS/Si/Al₂O₃ with the potential window of 0.01~1 V. The current densities are 0.2 A g⁻¹ for the 1^st cycle, 0.5 A g⁻¹ for the 2^nd and 3^rd cycles and 1 A g⁻¹ for the rest cycles. (c) Charge/discharge capacity of four electrodes over 100 cycles: Si film (black squares), CNS/Si with Si mass percent of 22.1% (red circles), 62.9% (blue triangles) and CNS/Si/Al₂O₃ with Si mass percent of 62.5% (green stars). (d) Charge/discharge capacity and Coulombic efficiency of CNS/Si/Al₂O₃ at high current densities ranging from 0.5 A g⁻¹ to 8 A g⁻¹.