fig4

Figure 4. Cyclic voltammetry curves of (A) Se@MIL-53-800 and (B) Compared CV result of different cathodes in the 5^th cycle at a voltage of 1.75–2.6 V vs. Li⁺/Li with the scan rate of 0.1 mV s^-1; (C) The discharge/charge curves at different cycles at the voltage of 1.75-2.6 V vs. Li⁺/Li with the current density of 0.2 C. The electrochemical properties of pure Se, Se@MIL-53-800, Se@MIL-68-800, and Se@MIL-100-800 cathodes in Li-Se cell; (D) Cycling performance and corresponding Coulombic efficiency at 0.2 C; (E) Rate capability and (F) Nyquist plots of these four different cathodes at fresh state.