Interface Engineering of Metal Phosphide on Hollow Carbons by Dual-template Method for High-performance Lithium-sulfur Batteries

Abstract Tailoring well-dispersed nanoparticles on the sulfur host with high catalytic activity is of great importance yet remains challenging in lithium-sulfur batteries (LSBs). Herein, a novel multi-phase interface structure of embedded CoP and Co2P nanoparticles (CoxP NPs) on hollow N-doped carbon substance (CoxP/NC) was successfully fabricated by the in-situ conversion of ZIF-67@ZIF-8 dual templates. The abundant multi-phase interfaces on CoxP/NC enabled efficient lithium polysulfides (LiPSs) capture, accelerated Li-ion diffusion, and boosted LiPSs conversion, thus forming a rapid and robust “adsorption-diffusion-conversion” network. Moreover, the well-defined hollow carbon polyhedrons physically inhibit the LiPSs diffusion and provide superior conductivity. As a result, the assembled S@CoxP/NC cathode with a high sulfur loading of 82% delivers an excellent rate capability (617.7 mAh g-1 at 3C), impressive stability (a small capacity decay of 0.053% per cycle over 1250 cycles at 1C), and favorable durability of thick sulfur cathodes (with a high areal sulfur loading of 4.68 mg cm-2 over 300 cycles).