Accelerating polysulfide conversion by employing C/MoS2 composite host for lithium-sulfur batteries

Abstract

Among various energy storage devices, lithium-sulfur batteries are the most promising candidate due to their high energy density and low cost. Polysulfide migration is a severe problem to inhibit the wide application of lithium-sulfur batteries. The efficient polysulfide inhibition is a determining factor for the high electrochemical performance of lithium-sulfur batteries. Therefore, the development of suitable host materials can inhibit that polysulfide inhibition has become a hot topic of research. Herein, we propose that the C/MoS₂ composites can be used as sulfur host to catalyze the polysulfide conversion to improve the cycle stability of lithium-sulfur batteries. Thanks to the presence of the C/MoS₂ host, the as-prepared C/MoS₂@S cathode exhibits high capacity even at high rate of 5 C. This work provides direct evidence for the catalytic effect of C/MoS₂ for accelerating polysulfide conversion kinetics.