关键词: 有序介孔碳, CMK-3/硫复合材料, 室温, 钠硫电池

Abstract: A series of ordered mesoporous carbon (CMK-3)/sulfur composite (C_xS_y) with different sulfur contents were synthesized via a melt-diffusion method. XRD, Raman, BET, SEM, and TEM techniques were used to characterize the structure and morphology of the as-prepared composite. The electrochemical performance of CMK-3/sulfur composite as the electrode of Na/S battery was tested at room temperature. Cyclic voltammograms show that one obvious reduction peak was located at about 1.61V, which is corresponding to the formation of Na₂S_x (x=2~5), while two oxidation peaks were displayed at about 1.82V and 1.95V, which are belonging to the decomposition of Na₂S_x (x=2~5). When the sulfur content in CMK-3/sulfur composite was 50 wt% (C₁S₁), the discharge capacity reached 500 mAh·g^-1 under 0.05C (1C=558 mAh·g^-1) rate in the first cycle and the capacity became 305.6 mAh·g?1 after 50 cycles. From the result of EIS tested at about 1.6 V under different temperatures, the activation energy was calculated to be 21.83 kJ·mol^-1. This result provides the basis for further study of porous electrode materials for room-temperature Na/S battery.

Key words: ordered mesoporous carbon, CMK-3/S composite, room-temperature, Na/S battery