3D copper foam/bamboo charcoal composites as high sulfur loading host for lithium-sulfur batteries

Abstract

In this study, a three-Dimensional (3D) copper foam/bamboo charcoal/sulfur cathode is designed for high sulfur loading lithium-sulfur (Li-S) battery. In the cathode, an interconnected conductive skeleton of 3D copper foam and the bamboo charcoal within the pores of 3D structure are facilitating fast ion and electron transport physically. The bamboo charcoal can improve the volume utilization. More importantly, the 3D copper foam can accommodate sulfur by chemically binding sulfur onto skeleton to form CuS. Based on the design, cathodes with sulfur loading of 6–10 mg can discharge and charge reversibly with initial discharge capacity of 1513 mAh g−1 and 1168 mAh g−1 and Coulombic efficiency of nearly 100% at 0.02 C. These results suggest that filling the pore of 3D foam with porous bamboo charcoal and combining sulfur on copper are effective to enable fluent electron and Li+ and offer enough sulfur accommodation for real applications of Li-S batteries.