Vigilancia Tecnológica

Abstract Lithium-sulfur (Li–S) batteries have received great attention due to their high theoretical specific capacity and energy density, wide range of sulfur sources, and environmental compatibility. However, the development of Li–S batteries is limited by a series of problems such as the non-conductivity and volume expansion of the sulfur cathode and the shuttle of lithium polysulfide. It is frequently feasible to alleviate these difficulties by blending carbon-based conductive additives with the cathode material, utilizing a nanostructured cathode, or enhancing the cathode's flexibility. Here, an ion/electron dual-conductive three-dimensional (3D) network structure has been constructed using TEMPO-oxidized cellulose nanofibrils (OCNF) and modified carbon nanotubes. We improved the ionic/electronic conductivity of the cathode materials by adding NCNT or SCNT, and also boosted its electrochemical performance through effective inhibition of polysulfide shuttling by amino or sulfonic acid groups that adsorb the polysulfide. The results showed that the 40-CNFSC@S composite cathode with the introduction of sulfonated carbon nanotubes (SCNT) contained up to 73.9 wt% of sulfur and exhibited the best electrochemical performance, with an initial specific capacity of 1052 mAh g?1 at 0.5 C, and the specific capacity was still as high as 837 mAh g?1 after 120 cycles. Its great cycling stability allows for environmentally friendly and low-cost cellulose-based materials to be utilized in Li–S batteries.