Preparation and Electrochemical Performance of Porous Biomass Carbon/Sulfur Composite Cathode Materials

• 1、School of Chemistry,Xiangtan Univerisity,Xiangtan 411105,China

Abstract：Lithium-sulfur (Li-S) batteries are nominated as one of the most promising next-generation electrochemical storage systems due to their relatively low cost, high capacity and theoretical energy density. However, the insulation of sulfur and the dissolution of intermediates polysulfide necessitate the addition of high conductivity matrices to enhance the active-material utilization, which are usually high-cost. In this work, the biomass-derived porous carbon (ALC) is fabricated by carbonizing bio-waste lotuspetiole and subsequently activating the material with KOH. The morphology, structure of the composites are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD). The as-prepared ALC possesses a large specific surface area of 2966 m2/g and an average pore size of 2.697 nm, introducing strong physical adsorption to significantly suppress the dissolution and diffusion of polysulfide. Herein, a high initial discharge capacity of 1358 mAh/g at 0.2 C with the utilization of sulfur is up to 81%, and large reversible capacity of 1064 mAh/g after 50 cycles at 0.2 C, meaning its outstanding prospects for the better cyclability and electrochemical performance as application of Li-S battery.

Keywords： Biomass carbon Elemental sulfur Cathode material Lithium-sulfur batteries