High sulfur content microporous carbon coated sulfur composites synthesized via in situ oxidation of metal sulfide for high-performance Li/S batteries

Abstract

Good progress has been made in improving lithium sulfur batteries through trapping sulfur in porous carbon materials by controlling the pore size. However, microporous carbon/sulfur composites suffer from lower sulfur contents through the traditional sulfur loading methods. In this paper, we present an effective and facile approach to prepare a double-hollow-sphere structured microporous carbon coated sulfur composite by in situ oxidizing the microporous carbon coated metal sulfide precursor. The composite efficiently traps sulfur inside the microporous-walled hollow carbon sphere. With the appropriate sulfur content ranging from 55 wt% to 75 wt%, the composites demonstrate promising cycling performance. The composites deliver a capacity retention of 96.11% at 0.2C after 100 cycles, and a relatively low decay rate of 0.05% per cycle after 1000 cycles at 1C.