Strong Lithium Polysulfide Chemisorption on Electroactive Sites of Nitrogen‐Doped Carbon Composites For High‐Performance Lithium–Sulfur Battery Cathodes

Abstract

Despite the high theoretical capacity of lithium-sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAh g(-1) after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca. 6 mAh cm(-2)) with a high sulfur loading of approximately 5 mg cm(-2), which is ideal for practical applications of the lithium-sulfur batteries.

Biomass-derived renewable carbon materials for electrochemical energy storage

“…To explore the potential of sulfur cathode, various carbon materials (including expensive nanostructured carbons, such as carbon naontubes (CNTs), graphene and ordered porous carbon) with high conductivity and suitable porosity have been used to host sulfur to leverage the poor conductivity of sulfur cathode and trap the dissolved lithium polysulfides [17][18][19]. In addition, plenty of carbon materials ranging from classic activated carbons (ACs) to nanostructured carbons have also been used as electrode materials for supercapacitors to push up their energy densities [20].…”

Nucleophilic substitution between polysulfides and binders unexpectedly stabilizing lithium sulfur battery

“…[5] This shuttle effect, together with low conductivity, leads to poor sulfur utilization and fast-capacity fade, which have hindered widespread use of rechargeable Li-S batteries. [6][7] Efforts to trap the shuttling polysulfides have mainly focused on meso/nano-carbon matrix as summarized by Liu et al, [8][9][10][11][12][13][14][15][16][17][18][19][20] formation of sulfur composites initiated by Wang et al [21][22][23] and metal oxide/sulfide hosts reviewed by Mai et al [24] Since divinyloxyhydroxyolysulphides was first developed by T.A. Skotheim et al as an alternative binder solution for Li-S batteries, [25] polymers including gelatin, [26][27][28] polyethylene oxide, [29] polyacrylic acid, [30] carboxyl methyl cellulose, [31] polyvinylpyrrolidone [32] , gum arabic binder, [33] carbonyl-β-cyclodextrin [23] and polyamidoamine dendrimer [34] were identified as promising binders to address the issue.…”

Structural Design of Lithium–Sulfur Batteries: From Fundamental Research to Practical Application

“…One of the most popular strategies to utilize nanocarbon is the integration of primary nanoparticles into microsized secondary structures [22, [164][165][166][167]. As shown in Fig.…”