Petroleum coke derived porous carbon/NiCoP with efficient reviving catalytic and adsorptive activity as sulfur host for high performance lithium—sulfur batteries

Abstract

Sulfur-host material with abundant pore structure and high catalysis plays an important role in development of high-energy-density lithium—sulfur (Li—S) batteries. Herein, we implanted NiCoP nanoparticles into the N,S co-doped porous carbon derived from petroleum coke (PCPC) to fabricate the sulfur-host of PCPC/NiCoP composites. The high specific surface area of PCPC provides abundant adsorption sites for capturing LiPSs and the NiCoP nanoparticles to improve the polarity and boost the LiPSs conversion kinetics of PCPC. The Li—S cells fabricated with PCPC/NiCoP as sulfur-host deliver high discharge capacity of 1,462.7 mAh·g⁻¹ under the current density of 0.1 C and exhibit ultralong lifespan over 800 cycles under the current density of 1, 2, and even 5 C. Additionally, the prepared composites cathodes deliver an outstanding discharge capacity of 932.5 and 826.4 mAh·g⁻¹ at 0.5 and 1 C with a high sulfur loading of over 3.90 mg·cm⁻², and remain stable about 60 cycles. Furthermore, the promoted adsorption-conversion process of polysulfides by introducing NiCoP nanoparticles into PCPC was investigated by experimental and theoretical calculation studies. This work offers a new light for tacking the obstacles of porous carbon-based sulfur-host and propelling the development of petroleum coke-based porous carbon for high performance Li—S batteries.