Multiphase and Multicomponent Nickel‐Iron Oxide Heterostructure as an Efficient Separator Modification Layer for Advanced Lithium Sulfur Batteries

Abstract Lithium sulfur batteries (LSBs) have been seen as of considerable potential candidate for lithium‐ion batteries (LIBs) to satisfy high energy density demand. However, the application of LSBs until now has been stubbornly dragged by the “shuttle effect” of lithium polysulfides (LiPSs) due to dissolution of LiPSs in electrolyte and reaction with the lithium anode, incurring a severe capacity decay. Herein, the straightforward separator modification method that multiphase and multicomponent nickel‐iron oxide heterostructure grown on oxidized carbon nanotube (NiFe₂O₄−NiO/OCNT) composites directly coated on the polypropylene (PP) separator, has been implemented, which effectively inhibits the migration of LiPSs, enhances the electron and lithium‐ion transfer, and promotes the redox kinetics by virtue of the heterostructure interfaces between NiFe₂O₄, NiO, and OCNT. In conclusion, the synthesized NiFe₂O₄−NiO/OCNT/PP separator delivers good rate capacities and high stability up to 1000 cycles at 2 C with a low‐capacity decay rate of approximately 0.065 % per cycle.