Nitrogen-doped carbonaceous scaffold anchored with cobalt nanoparticles as sulfur host for efficient adsorption and catalytic conversion of polysulfides in lithium-sulfur batteries. (1st July 2021)

• Record Type: Journal Article
• Authors: Fan, Bin; Zhao, Dengke; Xu, Wei; Wu, Qikai; Zhou, Wei; Lei, Wen; Liang, Xinghua; Li, Ligui
• Is Part Of: Electrochimica acta. Volume 383(2021)
• Publication Date: 2021-07-01
• Subjects: Nitrogen doping -- Lithium–sulfur batteries -- Lithium polysulfides -- High sulfur loading; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.138371
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The conversion of sulfur is accelerated effectively by as-constructed Co-NCNT scaffold. The rationally designed Co-NCNT guarantees efficient electrons/ions transfer pathways. The S@Co-NCNT cathode with high sulfur loading shows excellent performances. Abstract: The effective inhibition of lithium polysulfides (LiPSs) and promotion of their conversion in the redox processes is indispensable to achieve the long cycle stability and excellent rate performance of lithium-sulfur (Li-S) batteries. Especially, the generally slow electrocatalytic sulfur redox kinetics and large interfacial Li2 S nucleation energy barriers have hindered the widespread application of Li-S batteries. Herein, a robust three-dimensional sulfur carrier (denoted as Co-NCNT) is well-constructed using the potassium citrate derived porous carbon sheets as substrate and the catalytic growth nitrogen-doped porous carbon nanotubes as vertical scaffolds. Such a rationally designed structure guarantees efficient electron transfer pathways and ions diffusion channels. More importantly, it is conducive to the adsorption/catalytic conversion of intermediate lithium polysulfides and the nucleation of Li2 S. Due to these merits, the S@Co-NCNT cathode achieves an initial discharge capacity up to 1072.7 mAh g −1 at 1.0 C, and it can retain a high capacity of 482.9 mAh g −1 with a capacity attenuation rate of only 0.045% per cycle after 1000 cycles. Upon a high sulfur loading of 5.87 mg cm −2, the S@Co-NCNT electrode can still reach an initial capacity of 739.5 mAh g −1 at 0.3 C. Particular emphasis is that our work broadens the way to prepare well-designed carbonaceous materials sulfur host for long-life Li-S batteries. Graphical abstract: The cobalt-catalyzed growth of nitrogen-doped carbon nanotubes on the porous carbon nanosheets is well-designed as the robust scaffold for efficient loading of sulfur. It is manifested that this structure is conducive to the adsorption/catalytic conversion of intermediate lithium polysulfides and the nucleation of Li2 S, holding great promise in developing practically viable lithium sulfur batteries Image, graphical abstract .