Loofah sponge as a high-loading 3D carbon matrix for lithium-sulfur batteries

A loofah sponge-derived 3D carbon matrix (LSC) with large specific surface area and high conductivity is prepared via a simple chemical activation and calcination process. The characterization analyses reveal that plentiful pyrrolic N groups exist in LSC, which can provide strong affinity for polysulfides species through a coordinate-like Li-N interaction, and thereby effectively alleviate the shuttle effect and the capacity decay. The Li-S cell with S/LSC cathode delivers a high initial discharge capacity of 1392 mAh g−1 and a retention discharge capacity of 848 mAh g−1 after 100 cycles at 0.1 C. The results demonstrate that the loofah sponge can be a highly efficient and cost-effective biochar for the cathode of Li-S batteries.