Among Li-ion-based batteries, lithium-sulfur (Li-S) battery has been regarded as a promising candidate for nextgeneration energy storage technology to meet the urgent demand for breakthroughs in every aspect of industrial standard. However, several intrinsic drawbacks within the Li-S battery system still remain unconquered. For instance, Significant progress has achieved for developing lithium-sulfur (Li-S) batteries with high specific capacities and excellent cyclic stability. However, some critical issues emerge when attempts are made to raise the areal sulfur loading and increase the operation current density to meet the standards for various industrial applications. In this work, polyethyleniminefunctionalized carbon dots (PEI-CDots) are designed and prepared for enhancing performance of the Li-S batteries with high sulfur loadings and operation under high current density situations. Strong chemical binding effects towards polysulfides and fast ion transport property are achieved in the PEI-CDots-modified cathodes. At a high current density of 8 mA cm −2 , the PEI-CDots-modified Li-S battery delivers a reversible areal capacity of 3.3 mAh cm −2 with only 0.07% capacity decay per cycle over 400 cycles at 6.6 mg sulfur loading. Detailed analysis, involving electrochemical impedance spectroscopy, cyclic voltammetry, and density functional theory calculations, is done for the elucidation of the underlying enhancement mechanism by the PEI-CDots. The strongly localized sulfur species and the promoted Li + ion conductivity at the cathode-electrolyte interface are revealed to enable high-performance Li-S batteries with high sulfur loading and large operational current.
Lithium Sulfur BatteriesThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.
The plasticized poly(vinyl alcohol) (TPVA) was successfully prepared using poly(vinyl alcohol) (PVA) and 1‐butyl‐3‐methylimidazolium bromide (BMIMBr). Plasticizing effect of the degree of polymerization (DP) on PVA was investigated by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and melt flow indexer (MI). It was found that new hydrogen bonds between PVA and BMIMBr were formed, which was confirmed by the‐OH shift of PVA in FT‐IR analysis. XRD analysis showed that the original lattice and more irregular molecular chain structures in the amorphous region of PVA were destroyed effectively, which was conducive to the decrease of degree of crystallinity. Moreover, the plasticizing effect decreased with the increase of DP duo to more molecular entanglements in PVA. TPVA‐1799 possessed the largest thermal processing window and best melt flowability, which was significant for melt spinning in the future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.