Micro-nano structure composite cathode material with high sulfur loading for advanced lithium–sulfur batteries

摘要: ABSTRACT A micro-nano structure based on polydopamine-grafted hollow carbon nanofiber–sulfur composite (HCNF@PDA–S) is designed as a cathode material for effective trapping of sulfur and polysulfides lithium–sulfur batteries. Hollow nanofiber@polydopamine (HCNF@PDA) hybrid first prepared by an in-situ polymerization dopamine monomer decorating the surface HCNFs then elemental infiltrated into HCNF@PDA nanostructure thermal treatment. The obtained HCNF@PDA–S shows micron-sized nanofiber in length nano-sized polydopamine grafted outer surfaces with homogeneously distribution sulfur. Compared HCNF–S composite, high content approximately 80 wt% exhibits better electrochemical performance, which delivers initial discharge capacity 800 mAh g−1 maintains 530 after 200 cycles at 0.5 C rate. enhancements performances may be attributed to unique PDA coating layer, micro-sized offer electronic conductivity provide firm porous network tolerating volume expansion cathode, layers effectively prevent dissolution electrolyte.