Oxygen‐vacancy‐containing cerium oxide nanoparticle‐decorated nanonetwork‐structured carbon toward high‐performance lithium–sulfur batteries

Abstract

Lithium–sulfur (Li–S) batteries have been regarded as promising next‐generation energy‐storage devices owing to their inherently high theoretical energy density. Unfortunately, the poor capacity and cycling life caused by severe polysulfide shuttle effect and sluggish redox kinetics in sulfur cathodes greatly impede the practical application of Li–S batteries. Herein, a new class of nanonetwork‐structured carbon decorated with oxygen‐vacancy‐containing cerium oxide nanoparticles (NSC–CeO2−x), in which carbon skeleton is composed of highly conductive carbon nanotube core welded by hybrid carbon shell, has been developed via one‐step heating treatment of hybrid molecular brush and further employed as functional interlayer to modify separator of Li–S battery. Owing to the synergistic effect of the highly active CeO2−x nanoparticles and the three‐dimensional carbon nanonetwork in enhancing the preservation of the soluble polysulfides and boosting the redox kinetics of sulfur species, the NSC–CeO2−x significantly promotes the electrochemical performance of sulfur cathode. As a result, the as‐constructed Li–S batteries exhibit an ultrahigh initial sulfur utilization of 92.9% and an extremely large capacity of 751 mA h g−1 at a high rate of 5 C. Remarkably, a stable capacity of 728 mA h g−1 over 300 cycles at 1 C is also achieved.

Superfine SnO2–x Particles Embedded in a Porous Carbon Matrix as a Separator-Modifying Material for High-Performance Lithium Sulfur Batteries

“…Relative to the GO-modified material, SnO 2– x is introduced to enhance the adsorption and catalysis of polysulfides. Compared with the NSC-CeO 2– x -modifying material, the PC carbon matrix has abundant pores, so it has a higher specific surface area, which is not only more conducive to the adsorption of polysulfides but also enables the uniform distribution of SnO 2– x in PC. Therefore, the battery with the SnO 2– x /PC-modified separator has better 1 C cycle performance and lower impedance.…”

Alveoli‐Inspired Carbon Cathodes with Interconnected Porous Structure and Asymmetric Coordinated Vanadium Sites for Superior Li−S Batteries

“…[19][20][21][22][23][24][25] Therefore, the coordinated MÀ N 4 centers, especially FeÀ N 4 , CoÀ N 4 , and NiÀ N 4 stuctures have been widely explored in LiÀ S batteries. [26][27][28][29] However, the symmetric MÀ N 4 coordination structure shows a symmetric electron distribution at the metal center and results in near-vertical adsorption for polysulfide, therefore limiting the activation of reactants and conversion kinetics of polysulfide. [30][31][32] Heteroatoms with different atomic radii and electronegativity (such as B, O, F, P, and S, etc.)…”

Alveoli‐Inspired Carbon Cathodes with Interconnected Porous Structure and Asymmetric Coordinated Vanadium Sites for Superior Li−S Batteries

“…[19][20][21][22][23][24][25] Therefore, the coordinated MÀ N 4 centers, especially FeÀ N 4 , CoÀ N 4 , and NiÀ N 4 stuctures have been widely explored in LiÀ S batteries. [26][27][28][29] However, the symmetric MÀ N 4 coordination structure shows a symmetric electron distribution at the metal center and results in near-vertical adsorption for polysulfide, therefore limiting the activation of reactants and conversion kinetics of polysulfide. [30][31][32] Heteroatoms with different atomic radii and electronegativity (such as B, O, F, P, and S, etc.)…”

“…Recent studies have demonstrated that the monodisperse dispersed metal atoms with N coordination (M−N 4 ) can build atomic‐level contact/catalytic interfaces for accelerating liquid‐solid and solid‐solid conversion [19–25] . Therefore, the coordinated M−N 4 centers, especially Fe−N 4 , Co−N 4 , and Ni−N 4 stuctures have been widely explored in Li−S batteries [26–29] . However, the symmetric M−N 4 coordination structure shows a symmetric electron distribution at the metal center and results in near‐vertical adsorption for polysulfide, therefore limiting the activation of reactants and conversion kinetics of polysulfide [30–32] .…”