Iron Hexadecafluorophthalocyanine Nanoparticle/Porous Carbon Composites as Cathode Materials for Li–S Batteries

The shuttle behavior and sluggish conversion kinetics of polysulfides (LiPSs) significantly hinder sulfur utilization and cycle stability of lithium–sulfur (Li–S) batteries. Herein, iron hexadecafluorophthalocyanine (FePcF16) nanoparticles were in situ tailored on oxidized apple pomace carbon (OAPC) with a 3D porous structure to construct a high-performance FePcF16/OAPC sulfur host for advanced Li–S batteries. The designed FePcF16 nanoparticles have strong adsorption and catalytic conversion capabilities, which can reduce the redox reaction energy barrier, accelerate the conversion rate, and inhibit the LiPS shuttle. Meanwhile, the unique porous structure of OAPC effectively realizes the sulfur accommodation and rapid transport of substances. The average capacities of batteries with FePcF16/OAPC were 926.83, 847.11, and 782.63 mA h/g after 500 cycles at 1, 2, and 3C current densities, with capacity decay rates of only 0.020%, 0.031%, and 0.043% per cycle, respectively. Furthermore, it delivers favorable cycling stability at a sulfur load of 4.32 mg/cm2.