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

Lithium-sulfur batteries (LSBs) are promisingelectrochemicalenergy storage devices to answer ever-increasing energy storage demands.Its practical applications, however, are impeded by several technicalobstacles, with shuttling of polysulfides as the main cause. A compositeapproach was developed for the design of effective sulfur host materialsto tackle the issue. Here, cobalt sulfide nanoparticles embedded incarved N-doped carbon nanoboxes dispersed in iron single-atom decoratedmultiwalled carbon nanotube porous structure, S-Co@CCNB/SAFe-MWCNT,were developed as an effective sulfur host for LSBs. The sulfur hostcombines the high electrical conductivity and physical polysulfideconfinement capability of MWCNTs, the excellent polysulfides chemisorptioncapability of CoS2, and the high catalytic efficiency ofiron single-atoms toward polysulfide conversion reactions, to achievea high performance LSB. The S-Co@CCNB/SAFe-MWCNT based LSB delivereda 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 of550 mAh g(-1) was maintained after a 500-cycle operationat 1 C, giving a low average capacity decay rate per cycle of 0.043%. CoS2 nanoparticles embeddedcarbon nanoboxesdispersed in iron single-atom decorated MWCNT porous structure aseffective sulfur host for lithium-sulfur batteries.