Sulfur/nickel ferrite composite as cathode with high-volumetric-capacity for lithium-sulfur battery

Abstract

Low volumetric energy density is a bottleneck for the application of lithium-sulfur (Li-S) battery. The low-density sulfur cooperated with the light-weight carbon substrate realizes electrochemical cycle stability, but leads to worse volumetric energy density. Here, nickel ferrite (NiFe2O4) nanofibers as novel substrate for sulfur not only anchor lithium polysulfides to enhance the cycle stability of sulfur cathode, but also contribute to the high volumetric capacity of the S/nickel ferrite composite. Specifically, the S/nickel ferrite composite presents an initial volumetric capacity of 1,281.7 mA h cm−3-composite at 0.1 C rate, 1.9 times higher than that of S/carbon nanotubes, due to the high tap density of the S/nickel ferrite composite.