Built-in electric field accelerated polysulfide conversion for advanced lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage devices, but they still suffer by the shuttle effect and sluggish conversion of lithium polysulfides (LiPSs). Herein, we proposed a NiO-Co₉S₈ p-n junction heterostructure as a sulfur host material, in which built-in electric field traps while NiO catalytically converts LiPSs to suppress their dissolution in the electrolyte. Li-S batteries based on the NiO-Co₉S₈/rGO as a sulfur host material can exhibit high capacity, excellent rate performance (653.2 mAh g⁻¹ at 3 C) and an ultralow capacity decay rate (0.059% per cycle over 1000 cycles at 1 C). This work sheds light on heterostructure design for Li-S batteries approaching practical application.