Interface engineering of metal phosphide on hollow carbons by Dual-template method for High-performance Lithium-sulfur batteries

Abstract

• Hollow polyhedral sulfur hosts were constructed using a core–shell dual template. • Multi-phase interfaces boost the LiPSs kinetics. • The In-situ regulation of the surface physiochemistry on hollow substrates. • Excellent electrochemical performance of long lifespan with high sulfur loading. 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 Co 2 P nanoparticles (Co x P NPs) on hollow N-doped carbon substance (Co x P/NC) was successfully fabricated by the in-situ conversion of ZIF-67@ZIF-8 dual templates. The abundant multi-phase interfaces on Co x P/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@Co x P/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).