Fig. 5.

Excellent sodium-storage performance of as-prepared Sb₂S₃ electrodes. a CV curves of Sb₂S₃-150 in first three cycles with a scan rate of 0.1 mV s⁻¹. b Rate capability of the Sb₂S₃-120, Sb₂S₃-150 and Sb₂S₃-180 at various current densities (increased from 50 to 5000 mA g⁻¹). c Cycle performance of the Sb₂S₃-120, Sb₂S₃-150 and Sb₂S₃-180 electrodes at a current density of 200 mA g⁻¹. d Charge/discharge voltage profiles of Sb₂S₃-150 electrode for the first five cycles at a current density of 200 mA g⁻¹. e Three-dimensional Nyquist plots of Sb₂S₃-120, Sb₂S₃-150, and Sb₂S₃-180 electrodes at the open-circuit voltage. f Three-dimensional Nyquist plots of Sb₂S₃-120, Sb₂S₃-150, and Sb₂S₃-180 electrodes at a current density of 500 mA g⁻¹ after 50 cycles (the inset is the equivalent circuit model)