A comparison of sulfur loading method on the electrochemical performance of porous carbon/sulfur cathode material for lithium-sulfur battery

To get a high sulfur loaded porous carbon/sulfur cathode material with an excellent performance, we investigated four different sulfur loading treatments. The samples were analyzed by the Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) patterns, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). We proved that it is more effective to introduce the sulfur into the pores of porous carbon at 300 A degrees C than at 155 A degrees C. Especially, the porous carbon/sulfur composite heated in a sealed reactor at 300 A degrees C for 8 h presents a fine sulfur load with sulfur content of 78 wt.% and exhibits an excellent electrochemical performance. The discharge capacity is 760, 727, 744, 713, and 575 mAh g(-1) of sulfur at a current density of 80, 160, 320, 800, and 1,600 mA g(-1) based on the sulfur/carbon composite, respectively. What is more, there is almost no decay at the current density of 800 mA g(-1) for 50 cycles and coulombic efficiency remains over 95 %.