A sulfur-microporous (S-MIP) carbon composite was prepared for use as a cathode for rechargeable Li/S batteries. Two sulfur-embedded methods, S-impregnation (IS) and S-liquefied pore filling (LS), were applied for the preparation of the S-MIP carbon composites. The pristine elemental S of the polycrystalline α-S8 undergoes a structural change to an amorphous-S (a-S) structure in the S-MIP carbon composite created by the IS method. During sulfur loading of 40–50 wt %, the S-MIP carbon composite created by the IS method showed a BET SSA value of around 500 m2 g−1 and a pore volume of 0.2 cm3 g−1. However, after the LS process was applied to the S-MIP carbon composite, at 160 °C and 10 h, the a-S structure in the S-MIP carbon composite became recrystalline α-S8. Little remained of the porosity in the S-MIP carbon composite prepared by the LS method due to the large portion of the S crystalline phase. The best discharge capacity was obtained with an S-MIP carbon composite created by the IS method, with the result of 680 mA h g−1 after 50 cycles at 0.1 °C, i.e., ~47 % higher than that by the LS method.
This is a preview of subscription content, log in to check access.
This work was supported by the Next Generation Military Battery Research Center program of The Defense Acquisition Program Administration and Agency for Defense Development. We acknowledge the KAIST Central Research Instrument Facility for the use of Raman and TEM facilities, the National NanoFab Center for FT-IR facilities, and the KIER R & D Activity Center for SEM and XRD facilities.