fig4

Figure 4. Electrochemical performance of the electrode based on the sulfur mass: (A) Cyclic voltammetry curves of S@SG-CNT electrodes at a scan rate of 0.1 mV s^-1; (B) initial three discharge/charge profiles of S@SG-CNT cathode at a current density of 0.1 A g^-1; (C) rate-cycle performance; (D) the second charge/discharge curves of the S@SG-CNT at 0.1, 0.2, 0.5, 1.0, 2.0, and 5.0 A g^-1, respectively; (E) cycling performance at 200 mA g^-1; (F) the 2nd, 100th, 200th, and 500th charge/discharge curves of the S@SG-CNT at 0.2 A g^-1, respectively; (G) long-term cycling performance; and (H) long cycling life of the S@SG-CNT with four different mass loading of S at 2000 mA g^-1.