Efficient Polysulfide Trapper of Nitrogen and Nickel Doping Amylum Scaffold for Ultrahigh Performance Lithium-Sulfur Batteries
n recent years, lithium-sulfur batteries (LSBs) have attracted increasing attention due to extraordinary theoretical capacity, high energy density, eco-friendly and low cost of sulfur. But increasing sulfur loading and restraining shuttle of polysulfide are the primary issues to be solved. Herein, a novel N, Ni-doping amylum scaffold was fabricated by carbonizing amylum with urea and NiCl·6H2O (AC/Ni/N) at 1000 ℃ under Ar atmosphere. The AC/Ni/N scaffold was used to modify separator as an effective polysulfide trapper for LSBs. This AC/Ni/N modified separator not only exhibits a high polysulfide confinement, but provides abundant conductive pathways to permit the fast diffusion of Li+ ions and electrons. More importantly, the synergistic catalysis of Ni nanoparticles and N atoms plays a key role in improving the reaction kinetics of LSBs. Consequently, the LSBs with AC/Ni/N modified separator deliver a superior rate performance and ultra-long cycling life with a very low decay rate of 0.043% per cycle at 4 C. Moreover, the cathode with high sulfur loading of 7 mg cm-2 and low electrolyte of 7.8 μL/mg, delivers a high discharge capacity of 714 mAh g-1 after 100 cycles.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers