Abstract:
Lithium-sulfur (Li-S) batteries are considered promising energy-storage systems because of their high theoretical energy density, low cost, and eco-friendliness. However, problems such as the shuttle effect can result in the loss of active materials, poor cyclability, and rapid capacity degradation. The utilization of a structural configuration that enhances electrochemical performance via dual adsorption-catalysis strategies can overcome the limitations of Li-S batteries. In this study, an integrated interlayer structure, in which hollow carbon fibers (HCFs) were modified with in-situ-generated Ni nanoparticles, was prepared by scalable one-step carbonization. Highly hierarchically porous HCFs act as the carbon skeleton and provide a continuous three-dimensional conductive network that enhances ion/electron diffusion. Ni nanoparticles with superior anchoring and catalytic abilities can prevent the shuttle effect and increase the conversion rate, thereby promoting the electrochemical performance. This synergistic effect resulted in a high capacity retention of 582 mAh g-1 at 1 C after 100 cycles, providing an excellent rate capability of up to 3 C. The novel structure, wherein Ni nanoparticles are embedded in cotton-tissue-derived HCFs, provides a new avenue for enhancing electrochemical performance at high C rates. This results in a low-cost, sustainable, and high-performance hybrid material for the development of practical Li-S batteries.
摘要:
锂硫(Li-S)电池被认为是有前途的储能系统,因为它们的理论能量密度高,低成本,和生态友好。然而,诸如穿梭效应之类的问题可能导致活性材料的损失,循环性差,和快速的容量退化。通过双吸附-催化策略增强电化学性能的结构配置的利用可以克服Li-S电池的局限性。在这项研究中,集成的夹层结构,其中中空碳纤维(HCFs)用原位生成的Ni纳米颗粒改性,通过可扩展的一步碳化制备。高度分层多孔HCF充当碳骨架并提供增强离子/电子扩散的连续三维导电网络。Ni纳米粒子具有优越的锚定和催化能力,可以防止穿梭效应,提高转化率,从而促进电化学性能。这种协同效应导致100次循环后在1C下的582mAhg-1的高容量保留,提供高达3C的优异倍率性能。该新颖结构,其中Ni纳米颗粒嵌入棉花组织来源的HCFs中,提供了在高C倍率下增强电化学性能的新途径。这导致低成本,可持续,和高性能的混合材料,用于开发实用的Li-S电池。