A carbon nanofiber@mesoporous δ-MnO2 nanosheet-coated separator for high-performance lithium-sulfur batteries

Hollow carbon nanofiber@mesoporous delta-MnO2 nanosheets (HCNF@p delta-MnO2) with large surface area composite are prepared by a facile hydrothermal method and decorated on the celgard separator as lithium polysulphides reservoir for lithium -sulfur (Li -S) batteries. In this structure, the bifunctional HCNF provides excellent electrical conductivity and physical confinement of polysulfides. The porous delta-MnO2 coated on the wall HCNF provides more adsorption sites of polysulfides due to the large surface area. Due to the synergistic effect between HCNF and mesoporous delta-MnO2, the Li -S batteries with simple cathode (sulfur content reach 70 wt%) structure and HCNF@delta-MnO2 (coating thickness 2 [im) modified separator delivers an initial capacity of 1156 mA h g(-1) at 0.2 C and a reversible capacity of 856.1 mA h g(-1) after 200 cycles at 0.5 degrees C. This result provides a simple and scalable way to improve the electrochemical property of Li -S batteries.