A Universal Spinning-Coordinating Strategy to Construct Continuous Metal-Nitrogen-Carbon Heterointerface with Boosted...

Constructing intimate coupling between transition metal and carbon nanomaterials is an effective means to achieve strong immobilization of lithium polysulfides (LiPSs) in the applications of lithium-sulfur (LiS) batteries. Herein, a universal spinning-coordinating strategy of constructing continuous metal-nitrogen-carbon (MNC, M = Co, Fe, Ni) heterointerface is reported to covalently bond metal nanoparticles with nitrogen-doped porous carbon fibers (denoted as M/MN@NPCF). Guided by theoretical simulations, the Co/CoN@NPCF hybrid is synthesized as a proof of concept and used as an efficient sulfur host material. The polarized CoNC bridging bonds can induce rapid electron transfer from Co nanoparticles to the NPCF skeleton, promoting the chemical anchoring of LiPSs to improve sulfur utilization. Hence, the as-assembled LiS battery presents a remarkable capacity of 781 mAh g^-1 at 2.0 C and a prominent cycling lifespan with a low decay rate of only 0.032% per cycle. Additionally, a well-designed Co/CoN@NPCF-S electrode with a high sulfur loading of 7.1 mg cm^-2 is further achieved by 3D printing technique, which demonstrates an excellent areal capacity of 6.4 mAh cm^-2 at 0.2 C under a lean-electrolyte condition. The acquired insights into strongly coupled continuous heterointerface in this work pave the way for rational designs of host materials in LiS systems.