High-performance lithium-sulfur batteries using hierarchical Fe2O3/Ketjen black composites as sulfur host materials

The polysulfide shuttle effect limits the wide application of lithium-sulfur batteries, which have high energy density and specific capacity. In this work, hierarchical Fe2O3/Ketjen black (HFO/KB) composites are developed to improve the cycle performance of Li-S batteries. The HFO/KB hosts exhibit strong chemical adsorption toward polysulfide, which can effectively suppress the lithium polysulfide shuttle effect and further improve the utilization of active sulfur. As a result, lithium-sulfur batteries with Fe2O3/Ketjen black@S (HFO/KB@S) cathode deliver an initial discharge capacity of 1356 mAh/g and retain a high capacity of 1021 mAh/g after 100 cycles at 0.2 C. At the high rate of 2 C, the HFO/KB@S cathode exhibits a high capacity of 761 mAh/g after 500 cycles. This work demonstrates that the HFO/KB@S composites are promising cathode for future commercial applications of lithium-sulfur batteries.

Automated summary

In this study, hierarchical Fe2O3/Ketjen black (HFO/KB) composites were developed to enhance the cycle performance of lithium-sulfur batteries. By promoting chemical adsorption of polysulfide, the composites effectively suppress the polysulfide shuttle effect and improve the utilization of active sulfur. The results show that the HFO/KB@S composites have great potential as cathode materials for commercial applications of lithium-sulfur batteries.