A robust and low-cost biomass carbon fiber@SiO2 interlayer for reliable lithium-sulfur batteries

Lithium-sulfur batteries were investigated as promising next-generation energy storage devices owing to their high capacity in comparison to conventional lithium-ion batteries. Nevertheless, the serious shuttle effect and sluggish redox kinetics originated from dissolution of polysulfides and insulating property of sulfur and lithium sulfide, restricted their practical applications. To overcome these stubborn problems, a robust and environment-friendly biomass carbon fiber interlayer anchored with uniformly-distributed SiO2 nanoparticles was demonstrated. Benefiting from the excellent conductivity of carbon fiber, together with the stable chemical adsorption of SiO2 for soluble polysulfides, this low-cost and lightweight interlayer could not only remarkably enhance sulfur utilization, but also efficiently capture the polysulfides by chemical entrapment strategies. With this biomass carbon fiber@SiO2 interlayer, the batteries delivered a high reversible capacity of 1352.8 mAh g(-1) at 0.1 C and enhanced capacity of 618.4 mAh g(-1) after 500 cycles at 1.0 C. Even up to 4.2 mg cm(-2) sulfur loading, high cycling stability was also achieved by this interlayer. We believe this robust and low-cost interlayer has a great potential for practical applications of Li-S batteries. (C) 2018 Elsevier Ltd. All rights reserved.