A Review of Electrospun Carbon-Based Nanofibers Materials used in Lithium-Sulfur Batteries.

Commercial lithium-ion batteries are gradually approaching their theoretical specific energy, which cannot meet the fast-growing energy storage demands. Lithium-sulfur (Li-S) batteries are anticipated to supersede lithium-ion batteries as the next-generation energy storage system owing to their high atheoretical specific capacity (1675 mAh g-1) and energy density (2600 Wh kg-1). Nonetheless, Li-S batteries encounter several challenges, including the inadequate conductivity of sulfur and lithium sulfide, sulfur's volume expansion, and the shuttle effect of lithium polysulfides, all of which significantly impact the practical utilization of Li-S batteries. Electrospun carbon-based nanofibers can simultaneously resolve these issues with their economical preparation, distinctive nanostructure, and exceptional flexibility. This review presents the most recent research findings on electrospun carbon-based nanofibers materials serving as sulfur hosts and interlayer components in Li-S batteries. We analyzed the impact of the material's structural design on the performance of Li-S batteries and the relative underlying mechanism. Finally, the current challenges and issues faced by carbon-based nanofibers composites in the application of Li-S batteries are summarized, and the future development trajectory are outlined.

Enhancing conversion of polysulfides via porous carbon nanofiber interlayer with dual-active sites for lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage. However, the notorious lithium polysulfides (LiPSs) shuttle effect and torpid redox kinetics hinder their practical application. Enhancing phase conversion efficiency and limiting the dissolution of LiPSs are critical for stabilizing Li-S batteries. Herein, sulfiphilic defective TiO2 nanoparticles (D-TiO2) were integrated into the lithiophilic N-doped porous carbon nanofiber membrane (D-TiO2@NPCNF) to construct interlayer for catalyzing the conversion of LiPSs. The D-TiO2@NPCNF provides hierarchical porous structure and large specific surface area, and the formed 3D conductive network accelerates the transport of electrons and ions. The dual-active sites (N and D-TiO2) enhance the interface conversion and chemisorption ability of LiPSs via forming "Li-N and Ti-S" bonds. Due to the structural advantage of the D-TiO2@NPCNF, the Li-S batteries exhibit excellent cycling stability (only 0.049% decay per cycle in 800cycles at 1.0C) and impressive specific capacity (608 mAh g-1 at 3.0C). This work is expected to deepen the comprehension of complex interphase conversion processes of LiPSs and provide novel ideas for the design of new interlayer materials.

Preparation of cellulose acetate derived carbon nanofibers by ZnCl2 activation as a supercapacitor electrode.

Porous carbon nanofibers are fabricated by one-step carbonization and activation of electrospun cellulose acetate (CA) nanofibres. Electrospun CA nanofibers were obtained by the electrospinning of a CA/DMAC/acetone solution, followed by deacetylation in NaOH/ethanol solution. One-step carbonization and activation was achieved by dipping the as-spun fibers in ZnCl2 solution, followed by one-step high temperature treatment. The effects of the concentration of the dipping solution on the microstructure of the CA-based carbon nanofibers (CACNFs), including the morphology, crystal structure, porous structure, specific surface area and surface chemical properties, have been investigated. The coating of ZnCl2 effectively improves the thermal stability of electrospun CA nanofibers and obviously enhances the oxygen-containing surface groups of the CACNFs. The CACNFs have a norrow pore size distribution (0.6-1.2 nm) and a high specific surface area (∼1188 m2 g-1). Electrochemical performances of the CACNFs were evaluated as supercapacitor electrodes in 6 M KOH solution. The CACNFs demonstrate high specific capacitance (202 F g-1 at 0.1 A g-1) and excellent rate capability (61% of the retention from 0.1 to 20 A g-1). After 5000 cycles of the electrode, the capacitance is maintained at 92%, and the coulombic efficiency is close to 100%, showing high electrochemical stability and reversibility. The renewable features and excellent performance make CACNFs quite a promising alternative to efficient supercapacitor electrodes for energy storage applications.