Improving the Electrochemical Performance of Li-S Batteries via a MnCo2S4-CoS1.097 Heterostructure with a Hollow Structure and High Catalytic Activity

Rechargeable lithium-sulfur (Li-S) batteries are thought to be one of the most important candidate materials for new accumulated energy devices due to the preeminent theoretical specific capacity and energy density. Nevertheless, the shuttle effect of higher-order lithium polysulfide (LiPSs) severely impedes its actual practice. In this work, the hollow tubular MnCo2S4-CoS1.097 heterostructure composite is explored as the effective sulfur host to provide strong chemisorption and swift kinetics of LiPSs redox reactions so as to limit the dissolution and shuttle of LiPSs and obtain a prominent electrochemical performance. As a conse-quence, the assembled cathode based on the MnCo2S4-CoS1.097 heterostructure host exhibits a prominent initial specific capacity of 973 mA h g-1 at a high rate of 1 C and still retains a capacity of 762 mA h g-1 even after 500 cycles with a capacity decay rate per cycle of 0.041%. Especially, the MnCo2S4-CoS1.097/S cathode is fully operational even at a high sulfur load of 6 mg cm-2. Therefore, this work highlights a new strategy for the rational design of the heterostructure and provides a new idea for the industrial applications of Li-S batteries.

Automated summary

In this study, a hollow tubular MnCo2S4-CoS1.097 heterostructure composite is used as an effective sulfur host to address the shuttle effect of higher-order lithium polysulfide (LiPSs) in lithium-sulfur batteries. The assembled cathode based on this heterostructure host exhibits excellent electrochemical performance.