Cobalt Sulfide Nanoparticles Embedded Carved Carbon Nanoboxes Dispersed in Iron Single-Atom decorated Multiwalled Carbon Nanotube Porous Structure as a Host Material for Lithium–Sulfur Batteries

Abstract

Lithium−sulfur batteries (LSBs) are promising electrochemical energy storage devices to answer ever-increasing energy storage demands. Its practical applications, however, are impeded by several technical obstacles, with shuttling of polysulfides as the main cause. A composite approach was developed for the design of effective sulfur host materials to tackle the issue. Here, cobalt sulfide nanoparticles embedded in carved N-doped carbon nanoboxes dispersed in iron single-atom decorated multiwalled carbon nanotube porous structure, S-Co@CCNB/SAFe-MWCNT, were developed as an effective sulfur host for LSBs. The sulfur host combines the high electrical conductivity and physical polysulfide confinement capability of MWCNTs, the excellent polysulfides chemisorption capability of CoS 2 , and the high catalytic efficiency of iron single-atoms toward polysulfide conversion reactions, to achieve a high performance LSB. The S-Co@CCNB/SAFe-MWCNT based LSB delivered a high initial specific capacity of 1432 mAh g −1 at 0.1 C, with a decent specific capacity of 538 mAh g −1 maintained at 2 C. For cycling stability, a specific capacity of 550 mAh g −1 was maintained after a 500-cycle operation at 1 C, giving a low average capacity decay rate per cycle of 0.043%.

Single-atom cobalt encapsulated in carbon nanotubes as an effective catalyst for enhancing sulfur conversion in lithium–sulfur batteries

“…48 Materials with curved surfaces like the catalyst materials of Li–S batteries present novel opportunities for investigating and improving the characteristics of SACs in a variety of catalytic applications. 49–53 A study of the fundamental relationship between structure and properties is critical to identifying the parameters that have a substantial impact on electrocatalytic activity. Computational investigations such as molecular dynamics (MD) and density functional theory (DFT) have confirmed the presence of a ragged surface in catalysts.…”

Separator Modified by Carbon-Encapsulated CoFe Alloy Nanoparticles Supported on Carbon Nanotubes for Advanced Lithium–Sulfur Batteries

“…However, the physical and chemical adsorption of lithium polysulfides cannot effectively suppress the shuttle effect under long cycles and high-sulfur-loading conditions . Moreover, the sluggish redox of sulfur leads to the accumulation of lithium polysulfides in the electrolyte, which causes the shuttle effect and capacity attenuation. , In recent years, many kinds of metal nanostructures (e.g., Co, Ni, Sn, Fe, and Se/Te) as electrocatalysts have been developed in combination with chemical adsorption to effectively accelerate the redox reaction and alleviate the shuttle effect, thus improving the performance of Li–S batteries. Compared with monometal nanostructures, alloys are regarded as a significant group of heterogeneous catalysts consisting of mixed metallic components, which further increase catalytic activity, stability, and selectivity .…”